Structural Insulated Panel (SIP) House

PV Feed In Tariff

2011-06-15T12:46:00.001Z

It's now six months since I added a 2.1KW PV array to the house. The feed in tariff ( 42.8p unit + use all the PV energy you can) is a game changer as far as I'm concerned when comparing the costs of solar thermal with solar PV. At the half way point for the year it looks like this will generate over 2300 units of energy and pay back more than my annual electricity costs.

At the end of each quarter I submit the generation meter reading to EDF and about 30days later I receive payment.

The panels look ugly - but I can forgive them that. The system was installed by Solar Sam under the Navitron scheme. Good professional work and good system insurances come with the install. Unlike Solar thermals which drop off delivery as your tank gets hotter, PV panels keep delivering even in cloud conditions.

I used to say add PV electric once you had run out of all other energy saving measures, but now with FITS I recommend them at any stage.

(Poppies and other flowers on garage roof coming on :)

Green roof on garage

2011-05-13T21:38:00.002Z

I have almost completed a garage, and today I put on a green roof supplied by Sky Gardens in the UK. The Verdant Blanket consists of 80 species of native provenance, chosen for suitability to green roof applications. I have bees (note the Warre bait hive full of bees in the background) which swung me to the flowers even though I know a green roof will not supply them much ... if anything. Also I'm going to be able to see taller flowers on the garage than a low, sedum type planting. The cost of the blanket, substrate (a light bark like and crushed brick mixture 80 mm), drainage layer, fleeces and river stone edging is about £42 m2. We installed in one day. (2.5 man days - my thanks to Des and David). It weighed in total about 2.5 metric tonnes or 100kg/m2.

The second picture is the 'high tech' filter fleece and drainage layer. The cups store water, and also provide a drainage path under the substrate.

The EPDM covered roof is designed for loads up to 200kg/m2, with a 200 mm up stand and 6 degree slope to a single drainage hole. Greater than 20 degrees and green roof design gets more complex. I suggest if building from new, just use ibeams and let your supplier do all the load calculations.

If I had done a simple turf roof I would have need 250mm of earth and would have needed a much higher design load. While it may have been less 'technical' than this roof, it just would not have been practical for me. It often find green solutions require technology in my builds (like the drainage layer), which I try to resist as it somehow feels wrong, but often I have to give way to the practicalities or building regulations.

Energy use in a Structurally Insulated House

2010-03-31T14:16:00.004Z

Structural Insulated Panel houses have greater thermal efficiency due to good insulation properties (0.2 W/m2 K or better) and also air tightness. Below I have tried to work out how much energy was used in one year by my SIP house.

The summary is that I used about 11,000 KWh of imported energy for the year. A typical UK house uses 22,000 KWh (I expect a detached house of this size would normally use much more than this).

Imported energy splits as:

Electric = 6500 KWh (approx half not used for space heating)
Wood Burner = 4500 KWh (all for space heating - see below for calculation)

Home made energy contributions include:

Solar thermal/hydro = 1500 KWh (minimal space heating)
Passive Solar = 2700 KWh (I'm only including the special sky light window)

The split of energy is thus:

My conclusion is, while this SIP house has made a very large impact on my energy use, to go energy neutral would require a LOT more than a SIP house. I have no idea how Government targets to make energy neutral houses will be achieved unless they use some strange criteria. I would need a very large and expensive PV system to cover the gap. I've worked quite hard to get my energy use down, to do better every single detail of a house would need very careful consideration if you want to carry on living your life in a business as usual way. Maybe that is the truth of things - to have a house which is energy neutral requires us to use and consume far less.

Data for comparison and assumptions:

House area: 196 m2 detached
SIP Panels: 150mm Urethane and OSB
Location - South West UK
Occupants = 3 on average

Wood Energy
Dried (20%) wood = 11MJ per Kg. (note 1KWh = 3.6MJ) - oak/beech about 15MJ per Kg
1 m3 of 20% dried hardwood = 650Kg approx
1 year use = 3 m3 approx
Wood burner efficiency = 75% approx
1 year energy = (11MJ x 650Kg x 3 x 0.75%)/3.6MJ = approx 4500 KWh pa.

Passive Window
Based on a east/west contribution of 410 MJ m2 over a 33 week heating season the large 8x3 m2 window contributes (410 MJ x 8m x 3m)/3.6 MJ = 2700 KWh. (note window is actually inclined south facing in one direction and inclined east facing on another plane - so this is very approximate)

Solar Thermal
20 x 58mm evacuated tubes (approx 2.454m2 aperture)

Much of the data I use is from "Environmental Science in Building" by Randall McMullan. It's really useful for calculating heat losses, thermal storage, heat gain from windows, light, sound, ventilation etc. Simple breakdown of calculations and lots of worked examples at the end of each chapter. Not a cheap book, but good quality.

LED lights

2009-09-15T20:56:00.014Z

My very good friend Patrick hand made one of his beautiful LED lights for me. I really like the idea of hand made electronics when normally they are all mass produced.

I always pictured the jungle plants lit with green light and then another strong color in the background, and years later it's here.

I need the plants to grow a bit more, and get some of Patrick's new wall lights. It is very hard to do justice to quality and brightness of the light using a digital camera, but this was my best effort (much brighter in real life). You can select from hundreds of different colors for the front and back of the light, quickly changing to whatever you want. Some calm, some outrageously strong and pure.

Building can be fun, but I guess it is what you are left with that counts. If you build a house I think you need to list at least 5 really strong ideas before you start, and I think the indoor Jungle is one. Things have changed a lot since this post.

To see more of Patrick's lights and contact him visit ww w.smoo.co.uk

Are Heat Recovery Ventilation HRV worth it ? (Vent Axia HR250)

2009-08-08T19:40:00.015Z

Back working on the house again. This time fitting the Heat Recovery Ventilation system (HRV). It's a Vent Axia HR250 from ebay; £250 brand new with speed controller.

All houses need to be ventilated. Highly sealed SIP houses like this one need mechanical ventilation (passive is hard to design and control and cannot recover heat) otherwise you get condensation and poor air quality problems.

An HRV exchanges the heat energy from stale exhaust air to the incoming fresh air. This creates a rats nest of pipes at the HRV unit. Fresh air in, stale out, two feeds of warmed air to rooms, extracted air from bath room, small toilet room and, experimentally, a filtered cooker hood.

I've made my own control unit. Essentially it gets three boost signals to raise the unit from L1 (default trickle level) to L2 for small toilet (90m3/h @ 36w), L3 bathroom (112 m3/h @ 51w), Cooker hood (220 m3/h @190W).

The fans in the toilet and bathroom are icon 30 and icon 60 fans which automatically open when triggered by humidistats, IR sensors and lights. They each have in built timers. I disabled the icon fans and just use the boosted HRV to pull the air through the units. This makes them practically silent in operation now. Boosting is achieved with three 240v coil relays on IDC carriers in a small consumer unit, connected to 3 of the six 6 transformer taps in the speed controller (white box above). The relays are daisy chained to pass the highest boost level currently on demand to the HR250. Later I might 'break' the default L1 trickle ventilation rate if the outside air temp is very low or PIR sensor detects the house is empty.

It all works really well, is quiet and makes the air much fresher, especially in the mezzanine areas of two bedrooms which were poorly ventilated and uncomfortable before. As the fan is balanced (pulls air in while pushing the same amount out) it runs MUCH quieter than the noisy cooker and bath room fans it made redundant and more efficiently. The bathroom humidistat runs for a noticeably shorter time. The HR250 has two exhaust ducts. I'm using one on the cooker hood via a filter and I hope that stops it from clogging the heat recovery unit. I'm sure it will be OK as the cooker hood has run for year, and the pipes are clear.

Now how much energy do these things save over just exhaust fans? Well it's not easy to calculate, but here goes (making lots of assumptions):

Taking the volumetric specific heat capacity of air as 1300 J/m3K and the average outdoor temp here as 12degC, indoor temp 21degC, the designed ventilation rate for this house 30 l/s or 108 m3/h according to building regs, HR250 has a 70% efficiency.

The temperature of the incoming air is raised: 21-12 x 70% = 5.6 degC
The energy reclaimed = (1300 x 108 x 5.6)/3600 = 218W/h
Now the fan will use 51W to achieve this ventilation rate, so energy saved = 218 - 51 = 167W/h
Assuming continuous operation that's = (167x24x365)/1000 = 1,462 kWh
At 0.12p per kWh, that's £175 per year or about 750Kg of carbon saved.

Now that sounds good, but I don't run it at 30l/s, I run at less than half that rate in the summer due to high air infiltration from open windows and doors, and I use boosts when required, so perhaps the savings are going to be more? When running at lower speeds the system seems more efficient. I have measured > 80% efficiency at L1. Later, when the house is empty I want the system to shutdown, so not ventilating at all. I don't know how to calculate all these variables and you start to see why it's hard to work out the saving. I might know next year when I get my full year energy bill.

The system cost £800 when you include the HR250, ducts, vents and controls. As you have to ventilated the house to reduce condensation, smells and pollution it's definitely better than just simply ventilating with no heat recovery.

Tips:

Put a fresh air inlet close to the entrance of the kitchen to make cooking smell extraction more efficient and encourage air to going into the kitchen.
To reduce noise don't put a T duct junction closer than 1.5m from HRV unit, and use a soft Y junction.
Use acoustic ducting between rooms if there is 'cross talk' via the ducting, or for short outlet ducting. It is expensive if you get the proper stuff - it HAS to be acoustic ducting, don't accept insulated ducting with acoustic properties. This can cost 3x more than insulated ducting.
If you connect the cooker extract, disable the cooker hood fan which locally accelerates grease around the ducts and use the fan signal to demand maximum HRV boost. Use an additional in line-filter if there is any doubt about grease as this is not recommended operation and regularly check and clean the exchanger. Note as the system is balanced you will not need to run it at such a violent rate as before to get the same effect. I find the default trickle vent enough for cooking with lids on pots in summer.
Build time about 3-4 days for this job.
I choose the Vent Axia HR250, because it older technology, cheap, robust, easy to speed control, has multiple extract vents, and the company have a good and long reputation. I'm not sure the newer versions with pollen control and summer by pass filters, electronic control systems really justify an extra £1K.
In winter when the UNICO forced air heating system is on and the windows are normally closed, the HRV uses the house as a giant air mixing box. The UNICO system pushes the air to all corners of the house. I have seen designs with the HRV air inlet feeds only into the return of the forced air system to save using two sets of ducting. This really only works for forced air systems with cooling and heating ie. 24x7x365 operation. I do not use the UNICO system in the summer (The UNICO fan is 200W and I have no cooling option - not very eco!), so I need two sets of ducting. Fortunately my HRV ducting is very limited and 80% is in the loft room.

Strelitzia added to Indoor Jungle

2009-07-04T21:32:00.011Z

A new friend, Len, who lives close by and found this site, very kindly popped around this afternoon and gave me some Strelitzia (plus other jungle plants) to add to the bamboo and lemon tree.

The Strelitzia (big leaf plant in the middle - click for larger view) has been grown from seed, is five years old and currently 2m high. Hopefully in a few years it will reach the sky light (5m).

This is a picture of the first Strelitzia to flower in the 'jungle'. It suddenly appeared like this overnight. In the background you can see some of the 10 lemons on the lemon tree this year. As they are very precious I save them for my favourite dishes - tarte au citron and lemon drizzle cake (made with mash potato instead of flour!)

Future plans for the jungle area include figs and avocados. It's good to start moving from building a house to using a house.

Are bamboo floors green or just yellow?

2009-02-08T12:48:00.010Z

I've been putting in more flooring, and this shot is of the recently completed dining room. I have been looking for flooring and always had in mind to use Bamboo flooring as it's tough (but not as tough as a hardwood floor unless the bamboo is matured properly), looks good is relatively inexpensive, and doesn't expand/shrink so much.

There is also plenty of comment about its green credentials:

It grows very fast - 3 years to harvest, but 4-6 for harder wood.
The bamboo once cut regenerates
It can be grown with little fertilizer or pesticide

However there are downsides;

There is concern that a lot of forest is being replaced by commercial bamboo, and the bamboo is being more intensively produced
I live the other side of the world to where it's grown. I did a little calculation which suggested that the CO2 in shipping to my house was about 50% of the weight of the floor.
Bamboo strips are often bound using formaldehyde-based adhesive, which can be toxic though some manufacturers are producing formaldehyde free products.

So is it green? Probably not in my case because it's not local and in hindsight I should have asked more questions, but your mileage may vary. I'll research a few alternatives for other rooms (cork, linoleum etc.)

6kW house and Portfolio heating

2009-02-02T23:12:00.004Z

Many green homes use a portfolio of heating sources as the energy sources tend to be seasonal or have limitations.

Two design goals should be achieved:

The energy system should use the greenest in preference
The energy sources should be interchangeable (eg solar needs a back up)

My portfolio is:

Passive Solar from 8m x 3m Skylight. Works well even in winter on a clear day (adds about 7degC to the house).
Solar evacuated tubes - Hot water and heating system. Provides useful input for 6-8 months of the year.
Electric economy 10 immersion heaters (6KW) . Comes on only if Solar tubes cannot fill the thermal store. Not very green, and insufficient to heat whole house when -2C Deg outside. There is also a manual 6KW boost for heavy demand.
Wood burning Stove 5KW - main source of winter heating

Click picture for more details.

While designing this, I came to the conclusion that houses should reduce their energy to use no more than that which can be supplied with 6KW energy sources. This would be tough for most older houses, but easy for new houses. Why 6KW - well many energy sources are available at that range:

2 x 3KW immersion heaters
5KW wood stoves (typical small size, which requires no additional ventilation)
Air source heat pumps
etc.

Westfire uniq 21 wood burner and twin wall flue installed

2008-12-05T15:45:00.014Z

Well I finally found a Hetas installer, The Fireplace Fitters Shop Frome, who installed the westfire UNIQ 21 wood burner at a reasonable price and did a good job. I like this picture as it's one of the first showing a finished room, and I must admit sitting by the fire after the first lighting until midnight and thinking I've broken the back of the build. The picture also shows my guitar made by my friend Laurie http://www.parnellguitars.co.uk/ and my gold picture (the wall was built for the picture :). I have also put down some bamboo flooring and fitted a reclamation slate hearth.

While getting quotes to install the flue I found that all the Hetas engineers seemed to have different approaches, and some approaches fell short of building regs. Many quoted ridiculous prices (standard install quotes - regardless of effort involved) knowing that their building regs self certification would see off DIY installers who have to pay building regs over £145 ($350), assuming local building regs would accept a DIY install. My local building regs initially wanted a Hetas engineer to complete a commissioning test of anything I installed, but Hetas do not approve of this. Later they agreed a Hetas engineer was not required and they would check the install themselves. That's what the fee is for after all, but by then it was too late and I had booked somebody to do the install. My installer took a morning to fit the flue (two installers), but I did have one Hetas engineer quote 4 man days and another 2. I recommend you never accept a standard install quote and read building regs yourself first.

Building work is getting more tied up in regulations and approvals in the hands of "professional" bodies. The quality of these certified companies often leaves a lot to be desired. While I do not mind regulation and installers who really add genuine skill and experience, I think building control should always provide a service for DIYers to get their work approved and checked. Building regs for installation flues is very straightforward.

My only gripe about Flues is that very simple brackets cost a fortune. If you take the price of your stove and multiple by 2 or 3 you will not be far off the final install cost. It's worth checking online flue stores for price comparisons.

In the end we used a fire stop bracket (another amazing priced piece of metal - £128) on the exit of the flue to the SIP panel roof to ensure the twin wall never gets a chance to move out of position and close to the SIP panel and urethane (traditional houses use rafter brackets). The gap has to be >50mm. I going to monitor the temperature of the urethane, but so far so good and I believe urethane does not break down until about 200 degC. The twin wall on the exit is hot to touch, but not too hot. I'll also seal the exit hole with a ALU plate to restrict air into the flue roof hole. Using twin wall for the entire flue looks a little heavy but it improves the draw and burn removing the need for any special anti down draft cowls.

Here is a picture of me lighting my first fire. So satisfying.

Installing a Westfire UNIQ 21 wood burning stove

2008-11-22T20:27:00.009Z

My latest new project is to install a Westfire UNIQ 21 wood burning stove. In the picture is the kit of parts. I'm using twin wall flue all the way (no starter pipe which is the normal way) . Twin wall will improve the draw on a short flue. The risk is, if someone over stokes the fire, it could damage the twin wall. As the fire is a back up and less than 5Kw then I think the compromise is good. The pipe will look heavy, and the brackets for these things are ugly, but function will have to win over form this time.

Before I install the flue, I need to find out about passing the twin wall through the SIP roof. I think as well as the 50mm gap around the twin wall, I'll also need a radiation shield to protect the urethane core. Sadly I have yet to find a installer with experience of SIPS, but I think common sense and caution is required. I have thought about cutting the urethane back and filling it with rockwool (still keeping the 50mm air gap). The final problem using only twin wall is you need to sweep from inside the stove. This is not easy on the UNIQ21.

The hearth is from the local reclamation yard. £55 for a nice piece of 900mmx900mm riven slate.

I mention this is a back up system. Most green energy systems need to be from a portfolio of sources as they often have strengths and weakness. In my system I have just 6KW electric on Economy 10 plus solar (passive and evacuated tubes) energy stored in a thermal store heating the whole house and providing hot water. This runs out of steam when temperature outside dips to below -2C. So a wood burner provides a reliable independent source of heat. It has great green credentials ... so I'm told ... and hopefully it will dramatically cut my electricity use. I considered an air source heat pump, but their efficiency drops off badly at -5 degrees, and they do not generate the high temperatures I need for the thermal store. I guess it could directly heat the air, and this would get pushed around by the UNICO air handler, but I wanted something that looked great, was quiet and did not use electricity at all.

TDC 3 Solar Controller

2008-10-27T20:49:00.009Z

I thought I would talk a bit about the Sorel TDC 3 solar controller supplied by Navitron which pumps the water around the solar system. Essentially if the solar panel is hotter than the cylinder it turns on a relay to pump water around the system. Now this cost over £100 ($150), so it clearly it does a bit more.

One of them is collect stats, very useful, and as you can see by the picture (click) the panels produced more in October, than September, than August! What a summer. This is partly false as my heating has come on a bit in October making it easier for the panel to add heat to a cooler cylinder.

The TDC 3 has 15 different cylinder - multi panel - heat dump configuration options, stats, frost protection, variable pump control, purge settings, 3 relays, 2-6 temp probes, alarms, error logs etc. but do not let that put you off - it's really easy to use. More info here:
http://www.sorel.de/fileadmin/user_upload/pdf/BildschirmUK.pdf

The documentation gives very little information about how to optimally set up the pump speed, and there are a couple of modes for speed control (as there is for everything). I set it to variable pump speed and only start the pump with a high temperature difference between the panel and the cylinder (9 degrees) to start it and cut out when the temperature difference drops to 5 degrees. I set it like this as I have a long pipe run and I don't want a) short bursts of heat b) or lots of switching on and off which cool the tank in marginal conditions.

The other tricky thing is setting the Heat output settings (measure of KWH produced). Essentially you need to know the flow rate (difficult for variable control) and temperature drop of the pipe run. In practice you guess at these figure using a little maths and sensor figures, and then double check the KWH output with the temperature rises you see in the cylinder (use the maths in an earlier post to work out the KHW per degree rise). If the two figures do not agree, just adjust the parameters until results are consistent. The temperature drop variables are easier to figure out with the variable pump speed option turned off. It takes a while and will never be 100% accurate, but it is useful.

I think I could have got a much cheaper controller, but the information you get back from this can easily pay for itself by getting more out of your system and identifying problems quickly.

Solar evacuated tube performance

2008-10-06T20:11:00.021Z

I was going to write an 'I'm disappointed' post about the solar system, but I've been gathering the data and you know what? it's better than I thought it would be. The main reason for the anticipated disappointed was the terrible summer we have had. When I checked the controller from July (when I first set up the KWH logging) the system had only produced 550 KWH in the following 3 months. Now that is only £53 ($106) of electricity saving over a what should be a good 3 month period. I remember in an earlier post hoping for a minimum of £150 ($300) saving for a whole year (cost of the DIY install was just under £1500 - but could have been lower if I knew what I know now).

But then I starting thinking ...

Considering how bad the summer was (there were no clear days in the measuring period!) then we could have been looking at a minimum of 1100KWH for summer.
The end of September produced one of the best days (8KWH) - when the heating came on, and created more "room" in the cylinder for solar energy. In other words, sunny cold days produce more than hot days when the thermal store is full. This also explained the amazing return in April when I tested the system with a COLD tank on what turned out to be one of the few (only?) clear days of the year. So still more return to come in the winter.
I didn't fully lag the pipes until the beginning of September and fixed a leak which had reduced the pressure. This meant that I actually produced more in September than August.
Today electricity went up 20% (second rise this year) that £53 ($106) of electricity will cost £64 ($128) next year!

So I think perhaps I'm on track to make over 1500 KwH, £150 ($300)of saved electricity or better still 750Kg of carbon saving, despite the poor summer.

So worth doing - yes - but my special shower head http://www.mysiphouse.com/2007/07/sip-house-green-thing1_07.html still head wins hands down for green credentials. For a large family it can save just as much, but for just a £30 ($60) investment.

What have I learnt?

Lag pipes... Lag pipes!
Position the panel and the boiler as close as you can. With a total 50m pipe run I'm losing around around15% of the energy I produce even with 13mm lagging (except winter when it helps heat the house on the way to the cylinder)
The greenest things you can do are not the big ticket items
I didn't just buy alocal organic chicken because of payback. Some things should just be done because they are right

Building Control - nearly there

2008-06-24T14:10:00.004Z

I remember someone saying that building a house was like going on a train ride with no stops on the way. So true, but last week I called in building control for my completion certificate and apart from a cooker hood and small mods to the space saver stairs I'm nearly at the destination. I'll need some nice floor coverings - but after everything that's gone before it will be a minor detail. I think I'll use 15mm bamboo flooring. Apart from the distance it is shipped it seems as green as you can get. I looked at cork, but found that really hard to supply. Some of the new cork flooring is fantastic, and so much better than the 70's cardboard style tiles. My dad fitted cork when I was a kid in the kitchen, claiming it would reduce breakages ... not so I can report.

The picture was taken in June - a bit over grown on the grass front - but it's the only "building" work on site that gets done with no effort on my part. New additions include finished decking on the east side. You can see the aluminium angle eaves - I hate painting, so powder coated ALU angle seemed to be a great and under used method for finishing edges. Also on view are the inlet and outlets for the ventilation, and the Japonica moved back to the front of the house. I moved it away from digger peril during the main build. I used a tree spade to move it away (15 minutes), and three hours of digging by hand to move it back.

First day of operation for Solar panels

2008-04-10T19:05:00.002Z

First day of operation and another frosty start. The day ended cloudy and as this is April the sun is still low, outside air temp got to 9 degC, so I'm not expecting boiling water. Also the pipe runs are 49m and only 80% insulated atm.

Still, the results are good! Starting temp of cylinder was 20degC and the cylinder is 280 ltrs. At the end of the day the cylinder was 48 degC - Enough for a very..... long hot shower. A few calculations gives:

4.2 x 280ltrs x (48 -20)temp rise = 32928 KJ (or 33MJ)
33MJ / 3.6 = 9.3 KWh

(hmmh ... looks a bit high, possibly stratification of cylinder makes calculating the average temp rise inaccurate?)

The total capacity of the thermal store at 70degC is 16.3KWh, so if the figures are correct I'm impressed.

On average a household uses 50ltrs of hot water per person per day, or about 1.5 kWh at 55degC, so even on a cloudy April day I have hot water for 3 and a contribution of 4.5KWh to my heating (the thermal store cylinder does heating and hot water). As I also get a lot of passive heating from the skylight, so I can turn off the heating on sunny but cold days like this.

Before I get carried away, 1kWh costs about 5p on economy 10 (12p peak), so that's only about 45 pence saved today. I have to use some peak electricity for heating in winter, so although the contribution will be lower, the per KWh saving will be much greater, and I'm hoping to save £150 to £200 a year. The pump was on for 9 hours and controller 24x7 but that's not much energy compared to the gains.

Think of all that CO2 saved today (9.3 x 0.43Kg = 4kg). 1kWh electricity produces 0.43Kg of CO2 according to National Energy Foundation.

Shower was good, seemed identical to a .... normal shower, funny that.

Things can only get better.

Solar tubes fitted

2008-04-09T20:03:00.003Z

This shows the first 5 58mm tubes fitted, and yes they are covered in frost. You might just notice the simple air vent arrangement on the left of the manifold by the cold inlet. The hot return doubles back on manifold and the vent pops up by the cold inlet to the manifold. I did this to position the air vent 1.8m ,following the copper pipe, from the manifold to prevent the tiny rubber seal from melting in extreme conditions. If that does not work I'll use a different seal material (leather?) as it's a simple disk. Having the vent in free air, and having it drain to the roof and gutter also helped. I fitted the rest of the tubes that night, but during the day just the five tubes worked for 2 hours on a cold April day when the outside air temperature was 8 degrees.

As I haven't filled the pipes with Antifreeze yet, I set the controller to circulate the water if the manifold got to 3 DegC. Well it did! so unlike every other post saying on my first day I had a nice hot shower, I can say that on my first night I lost energy :) Ah well not much and I found it funny. The controller poped up a little information alert warning about it for me to read in the morning - so at least I know that bit is tested.

Plumbing in the solar Panel

2008-04-09T19:34:00.006Z

This shot shows the only 'complicated' plumbing. All it does is pump the water/antifreeze mixture from the solar coil in the cylinder back up to the solar panel for heating up again.

Rather than plumb the tricky bits for the solar panels in place I decided to mount them on a board, and then fit the board into position when it was mostly done. Connecting this to the system was simply a matter of connecting to the return from solar coil (lower of the two coil connections) in the hot water cylinder and the other end to the cold return at the panel. The rest of the plumbing consists of the hot return from the panel to the solar coil inlet (higher of the two coil connections)

The picture (click for more detail) shows the pump and expansion vessel. The solar controller sits on top of the pump (not shown) inset into the polystyrene insulating casing. The parts were purchased from Navitron and consist of a flow box 700 + TDC3 controller and a pressurised system kit. Short points to make on this picture are:

Just above the pump is a clever one way check valve with several features. The check valve stops thermo-siphoning at night (solar system working in reverse). It contains a slot for a temperature gauge (not fitted in the shot). The valve can be twisted during commissioning so that the pipe work both sides of the valve can be filled (saves having a by-pass pipe and commission valve).
The expansion vessel keeps the system at about 1.5bar, so no header tank is required for the closed system. A combined filling tap and 3 bar pressure release valve is fitted. The pressure release is an important safety feature and in the final system a vessel will be added to catch any fluid if the release valve trips.
I added two simple air vents - I really only needed one, and that probably could have been an auto-vent, but I didn't have one handy.
The pipes need to be insulated with ARMA flex insulation, but I guess the return piping is not quite so hot, so I guess cheaper insulation could be used here, at your own risk. Most DIY shed insulation melts above 70degC.

As I mentioned earlier I hate compression joints - this had three weeping joints when I connected it up. Duh! I'll use fernox pipe sealant next time.

Solar evacuated tube installed on roof

2008-03-25T21:00:00.008Z

Yikes! I underestimated this task. SIP roofs have a construction of SIP panel, membrane, vertical batten (for ventilation) and horizontal batten for the tiles. This means you cannot run the pipes into a loft space, as there often isn't one on a SIP house and you have to run the pipes between the battens as shown in the picture (click picture for more detail).

That might not sound difficult, but all the plumbing by the panels has to be compressions joints (I hate compression joints!) as the temperatures within 1 m of the tubes could melt solder joints in failure conditions (solar stagnation).

Then there is the air vent problem ... what a pain. You want an air vent at the highest point (right next to the tube's manifold) but nearly all air vents have plastic components which can melt if placed close to the manifold. I solved this by putting a thumb screw vent on the hot water return just where it runs past the cold inlet on the left (1.8m from the hot outlet and in free air). I poked it out of the roof because there was nowhere to run it inside the house, and on the outside so it can at least vent to the roof and gutter while I'm filling the system. This means four holes in the roof tiles (thank god for diamond cutting drill bits) : cold inlet, hot return, temperature sensor, and air vent.

Things to remember next time - get a bigger hole cutter (4mm bigger than the tubes), the extra tolerance makes fitting pipes to tiles easier and also easier to push silicon deep into the joints.

I'll add the tubes at the very end when everything is working.

It's not as steep and I'm not as spider man as this picture looks.

DIY solar evacuated tube install

2008-03-25T20:41:00.006Z

Looks like this will be green thing 10 out of 10. I ordered from www.navitron.org.uk a 20 tube solar evacuated solar collector. Ordered on Sunday and it arrived Thursday, and here is a shot of the kit waiting for me at the front door.

Perhaps the design choices for the solar panel might be useful. The system will be used to heat a 280 ltr thermal store (with solar coil in-built) used for heating and hot water. Thermal stores operate at much higher temperatures (70C deg) and volumes than normal cylinders. So design decisions are:

a) Evacuated tube - gives some winter contribution and overcast/low angle contribution
b) 58 mm tubes (larger than standard 47mm) for 50% extra performance
c) Flow box 700 + TDC3 controller as I need to heat the cylinder to its limits and therefore control is important.

The control system and heating contribution ruled out flat panel designs pumped by solar powered pumps. The parasitic losses from the pump and controller are outweighed by the extra solar heating contribution.

I'll mention one thing about the picture and that is the flexible aramaflex tubing. You need higher temperature insulating tubing as normal DIY tubing often deteriorates at 70C deg plus range.

More install posts later!

Green thing 9 out of 10

2008-03-03T22:34:00.006Z

I've been slipping on my posts, and struggling to reach green post 9 out of 10, but here it is - Changing air only when I need to and via a heat exchanger.

These two pictures show the fans in the 'wet' rooms (bathroom,toilet). The wet rooms each have a exhaust fans and these are connected together. They can be set to trigger on humidity (bathroom) or light on (toilet room which has no window - and hence automatic light and suitable trigger). As the humid air exits the building it does so via a passive heat exchanging, passing the heat from the exhaust air to the incoming air.

I chose the AIRFLOW Icon fans as you can have different trigger modules (IR, humidity,trigger) and they look so cool when they open ! The Icon 60 is a bit noisy and big for the bathroom, but its really powerful and clears the air in seconds. As its only on when the humidity is high, it comes on only at the end of my shower.

One of the Icon fans failed after 1 year. AIRFLOW have a 3 year guarantee and they changed it straightaway.

I'm thinking of connecting the Icon 60 to the C02 monitor to assist with forcing air out via the heat exchanger as I suck in fresh air using the UNICO air handler (or a smaller in let fan to save energy.) Something I'll experiment with in the summer.

UNICO heating and cooling

2007-10-27T17:41:00.002Z

If you look very carefully you can see the heating/cooling system in the ceiling of the dining room (Top left and the rectangular slot ... click the picture to get a bigger view). This time I've 'boxed in' the ducting.

This shot was taken hours after the walls got their plaster skim. In my system, the UNICO system uses a single hydroponic radiator in front of fan and ducting system to heat the house.

On days when it is too hot the system blows cool air from the shaded north wall. A further modification to the UNICO system (under development) is a CO2 control system to add fresh air when needed. So far the CO2 levels are too low to trigger a control valve. Another addition to add is a passive heat exchanger to transfer the heat from exiting stale air to the incoming fresh air. The heat exchanger and Co2 monitor can be green thing 8 out of my 10 and we shall call it "Only change the air when you have to".

So when I have finished the UNICO system will provide:

Heating
Cooling
Air quality control
Passive heat distribution

Green thing 7, no skips

2007-10-27T15:30:00.001Z

It's been a while since I uploaded a current picture of the SIP (structural Insulated Panels) house, so here is a picture. We could call this green thing 7 as its shows no skips. Where possible I use everything. For example, where I use to two layers of plaster board to create wiring channels, the first layer is all the off cuts. Broken tiles are used for rubble under the decking and the list goes on. It is time consuming, but I guess thats why people create so much waste. We are all in a hurry.

Efficient cooking: Green Thing 6

2007-07-14T13:40:00.001Z

Everything helps and fits together. This is an odd picture of the induction hob. Hobs like these are 40-70% more efficient than other types of hob (halogen, electric and gas being the worst) and safer also as the pan gets hot and not the hob. They work by creating eddy currents (magnetic fields) in the pan. So all the energy goes to the right place - and not heating up the kitchen (which is not good in a super insulated house!). The heat is extremely controllable.

LED lights: Green Thing 5

2007-07-14T13:31:00.001Z

These are great, LED lights. Green facts are:

2.4 watts (similar light to 25W GU10, or 7W low energy fluorescent)
Instant on (unlike slower low energy fluorescent cousins)
Very low heat (safer)
12,000 hours (much longer than the fragile low energy version).
Cost about £7 each

Thermal Store: Green Thing 4

2007-07-09T18:40:00.001Z

Ah my love ... my thermal store Betsy. Looks a bit complicated but basically it stores energy in a big water cylinder (nothing new there I hear you say) and releases it to the cold water supply via a heat exchanger (slightly different). Three supplies of energy, with the greenest and cheapest at the bottom of the tank; solar connection, further up economy ten elements, and then for those really cold days when everybody wants showers standard rate boost elements (not used very often!).

Passive solar heating. Green thing 3 of 10

2007-07-08T08:00:00.000Z

The house gets lots of heat simply from the skylight. Most days it is 7 deg C warmer inside just because of the passive heating and insulation.

During the summer this can get too hot so the ventilation system can bring in cool air from the shaded north wall and the 3 folding sliding doors allow the roof to act as a shaded canopy

Post a comment if you know the name of the plant in the first picture!

Insulate Insulate Insulate - Green thing 2 of 10

2007-07-08T07:47:00.002Z

Ah ... a picture of a Structurally Insulated Panel (SIP) which is used to form the envelope of the house ... and a bit of tinsel ... why not.

The house uses 75% less energy than a conventional home of equivalent size, mostly because of the insulation properties of the panels. I'll add my solar panels only when I have run out of ideas for not using energy in the first place (like energy saving shower heads).

SIP House - Green Thing 1of 10

2007-07-07T12:33:00.001Z

I'm going to publish 10 green things (ala 10 green bottles) about my house for the sustain Frome trail.

This is the best green thing in my house! It's an oxygenics shower head and it took 2 minutes to fit.

This one delivers a great shower (even at low pressure) at < 5lt per minute by adding air to the jet. Why is this good? Well a typical power shower will use 15ltr+ minute. Doing some maths (making all sorts of assumptions about cleaning habits) this could mean wasting 250ltrs of water of hot water per day for a family of 5. The cost of water and heating (making all sorts of assumptions on water rates and heating sources) can easily add up to over £250+ pa higher bills than if a simple £20 shower head was fitted. Even if you are single, it should pay for itself in a year ... but first measure how much your shower uses, no point changing if you have weak shower

Note: There are plenty of papers advertising water saving shower heads. Most seem to start at 9ltr per minute, which I think is still too high.

So less running out of hot water, saving C02 and water, wetter (because of the added air) showers. Seems good to me. Pop round if you want a test drive - bring your own soap and towel.

This could be the best energy saving device I have fitted.

Sip Panels get some Plaster

2007-05-12T07:33:00.003Z

At last - some seriously good plastering done by Duncan Gregory and friends who did a fantastic job with all the tricky high bits, shadow gaps around doors and big surfaces. They also didn't complain about my dry lining so top marks there also.

Never in the history of plastering has so much tea been consumed by so few. I'm feeling like I'm on the home straight.

The skylight is looking good and really pumping in the passive solar heating. The unico air handler sucks it via loft window into the loft space before it is distributed by the ducting around to all the rooms. In the summer time the unico system is used to dump the excess heat, but I think I'll just open the folding sliding doors, which turns the roof into a shaded canopy.

The shot shows how I think SIP panels should be used; made to create new shapes for houses and not copying old box rooms.

How do you wire a SIP house ?

2007-02-22T13:46:00.000Z

As there are no voids for wiring how do you wire a SIP house? The answer is with a lot less hassle than a conventional house.

Using a double layer plasterboard, fix the first layer to the SIP wall or roof panels leaving a suitable void between the sheets of plasterboard where the wiring is to be situated.

Having installed the wiring you then mechanically fix the second layer of plasterboard over the first layer.

If using 12.5mm plasterboard, use 30mm gang boxes for switches.

A further benefit of the double layered plaster board is:

A class 0 fire rating
Firmer, quieter walls than say a timber frame stub partition
Better insulation

My top tips for wiring are:

Locate as many sockets as possible on outer walls to get maximum insulation benefit
Try not to wire internal walls to save on time and plasterboard (unless you want that class 0 fire rating).
Always use a generous tubular sleeve when passing through SIP panels. You don't want the wires overheating and this is correct wiring standards practice.
Always run the wires in approved locations (see IEE regs) or protect runs with suitable metal cover if deviating from the approved routes for wires (150 mm from wall/ceiling corners and horizontal/vertical to switches)
Always get the wiring properly checked. While I was able to DIY my own due to the date of my building regs application, I still got an independent party to test them. The tests are quick and very sensible.
Use off-cuts of plasterboard for the first layer of boarding. It doesn't matter how messy it looks but it will save money and skips. Bit timing consuming though, but that's why people have skips - because they are always in a rush.

SIP houses and ventilation

2006-12-08T12:47:00.002Z

One of the problems of building a highly sealed house is the issue of getting fresh air into the house. The latest UK building regulation mandate how many ltrs of outside fresh air should go into a house based on size and occupancy, but also allow for specialty systems. As my application for building came in before these requirements I do not have to comply, but where I can I like to meet or exceed building regs. For outside fresh air I have added a C02 monitor from www.telaire.com. This monitors C02 and if above 1000ppm it actuates an electric damper, which allows the UNICO system to suck in fresh outside air as well as returned air from the house. This way I only heat outside air when I need it. In practice I have found that the damper needs to operate far less frequently than I expected, so I'm really glad I took this road, rather than simpler 'punch some holes' in wall approach.

[Later Update - In practice I've found the ventilation requirements to control humidity mean that a CO2 monitor is not required. But I'll post more on this later]

Humid air from Bathrooms and kitchens will be extracted when needed via a passive heat exchanger. I looked at the active exchangers, but the initial investment, complexity and running costs did not seem to stack up. I've yet to hear of a satisfied customer for these things and the 90% heat recovery claims in the brochures may be true in the lab, but in practice the experience seems under whelming.

In the summer you can see from the picture that the two folding sliding doors can open so the roof acts more like a shading canopy. For extra cooling I can also blow in cool air from the shaded north wall (brick wall with single window in the picture) using the HVAC (where AC stands for air cooling :) system. The picture also reminds me I have one more folding sliding door to go - just need some energy!

Tornado and Fire

2006-10-25T15:43:00.000Z

Sip houses are normally a lot stronger than timber frame houses and contrary to popular belief they don't burn very well either. If you want proof, have a look at the pictures of a house that took off in a tornado, and another house that caught fire here:

http://www.achfoam.com/SIPs/news/articles/tornado.asp

I think the only issue this link raises is strapping the top half of the house to the bottom half! If I remember correctly I have over 150 galvanized straps doing this, it took me days and even then Build it Green had to 'adjust' many of them. Here is an early photo of the straps: You can just see the straps sticking up either side of the timber sole plate, securing them to the block and beam floor. Further straps were added every 2m around the house to prevent vertical take off. All seems like a long muddy time ago now.

More decking & folding sliding doors

2006-10-09T15:06:00.000Z

Yet another folding sliding door, this time at the front of the house and this one is wood. Wood is so much harder to work with because of the finishing work and the slight tolerence differences. So this one took two days to install and 3 to varnish, hinge and fit all the rubbers seals. Still job done. Oooh and more decking, thanks to my mate Paul, who being 6'3" was very handy for the high bits.

Work build play

2006-09-24T08:33:00.000Z

You know when you take on a build you have to be totally committed and focused. You get on a train with no stops on the way to the destination (unless you derail).
That means everything in your life has to go to one side.

Well my life is starting to come back and these shots have nothing to do with building and everything to do with the future.

This is my Gold picture (I like art and this house would make a perfect gallery) and my guitar which I have so badly neglected, mostly due to blisters, splinters and cuts as well as time.
My good friend Laurie made the Guitar http://www.parnellguitars.co.uk/. It took a year of discussion and making. It uses some local wood (even a bit from a tree in Frome park). One of the strings went last week, so proof that I'm back in action.

Folding Sliding Doors

2006-09-05T13:01:00.000Z

Fitted a Folding Sliding Door this weekend with my brother. Two more to go. The doors are from .... www.foldingslidingdoors.com of course, and I think they were the best value for money and I'm pleased with the quality. These are made from ALU, the other two are timber.

Fitting took a long day, and use of a good spirit level (bottom right!) is essential. Note my plants have magically moved into shot again. The protea need as much light as possible and this is the first time in the build that they have got what they wanted.

Both Protea should flower this year, they need light,warmth and breeze. The FSD should help with all three. Interestingly not only will the Protea produce massive flowers, they also take moisture from the air which should be useful.

2006-08-17T20:03:00.000Z

Blow the Heat

2006-08-15T15:59:00.000Z

These shots show the how the heat is distributed. You can use 90mm supply tubes which send the heat/cooling to right places (amazing acoustic properties - sound does not travel down the tubes)

Or you can use rectangular fibre boards which has slots cut in for the heating/cooling. Note the fibre board can be painted if you are careful or boxed in (I'll do both methods depending on the room). The open window to the left acts as a return path for the air to air handler.

UNICO system

2006-08-15T15:53:00.001Z

The newly installed air handler system. Working from right to left the silver box consists of:

1) mixing box (mixes fresh outside air via a passive vent axia heat exchanger ... tbd!) with returned air from the house. It also includes an air filter to help me dust :)

2) A 12Kw hydroponic radiator. The only radiator and heating source for the whole house.

3) An empty box - for anybody who wants air conditioning! I'm relying on cool fresh air sucked into the house (from the shaded north wall) by box 1.

4) A fan to push the air around the house.

Note far left of the picture the air splits left and right to feed both sides of the house before returning back to the loft and the air handler. So far it has been a simple 4-5 day DIY install. The air handler electrics are simple and look very robust.

Jungle walkway

2006-08-14T15:41:00.001Z

Decking on the inside also! This time around the internal Jungle, linking the bedrooms and lounge space.

The rectangular tubes are the heating and ventilation system ready to be suspended from the ceiling once my knee recovers from a recent football injury.

If all the world

2006-07-16T09:29:00.001Z

If all the world thought like me, the world would be a very boring place. Not that I think I'm particularly boring, it's just that sometimes it's good to have you ideas challenged, and to try things that you think might be wrong. This picture shows one of them. Paul (architect) wanted to use decking for cladding the walls. I thought that would be wrong, and everybody would say 'why have you used decking on your walls?'. Well I was wrong, it worked great, and really the question should be 'why don't other people use decking on the walls?' It's tough wood (yellow balau - at least 30 year life), the grooves give texture, and the colour variation between the boards give good visual interest. My only concern is it's not locally sourced and can you really trust these certificates about managed sustainable forests ? At least I got it from the local timber merchant, www.timbersource.co.uk . Great service, and a bit of a find.

A Boring Post on Energy Losses

2006-06-23T15:59:00.002Z

I often get asked about energy costs and green issues regarding just using electricity. Although I could easily use gas, I don't. Why?

1. Well its true that electricity transmission lines can lose very large amounts of the energy in just heating the lines (900MW at peak for UK), but energy loss is IxIxR (I= current, r = resistance). In other words losses on the national grid rise rapidly with load. So a half time world cup cuppa is going to take more energy than a late night keep you awake cuppa. If you get your energy at night (economy 7) and store it in a thermal store (see earlier post), then if the night time load is 10 times less than day time, the energy loss by transmission is 100 times less. Switching off set top boxes is good but load balancing would save much more energy. However in practice total peak loss is approx 2.5% (National Grid figs 2006), or about 1.5GW (variable and fixed losses), so that world cup cuppa is probably OK after all.

2. Gas standing charges, boiler insurance and inspections cost £200 a year. That's just over half all my hot water and non heating electricity costs a year.... but there is more, oh yes ... Since deregulation, gas installation costs have rocketed from a few hundred to £2500 and a decent boiler + fitting costs £2000. Ouch, that's before you get any heat benefit. Go figure! Where self builders go first, others will follow.

3. It's easy and safe to DIY electricity and heat (solar elec/hydroponic,wind,passive gain), but the same is not true of making and storing gas.

4. Gas costs about 2.9p a unit and Economy 7 just a little more. But consider that modern gas boiler breaks down typically after 5 years and are very expensive and not as efficient as simple electric elements (30 quid) in a thermal store tank.

All makes sense to me, but I'll do a final 10 year calculation after I get my first year energy costs.

view from google sketchup

2006-06-02T13:07:00.000Z

This view from above was created by my architect Paul Redman using google's sketchup. Click the picture for a bigger view.

Paul did a great job turning my ideas into a good design. Another job Paul did and contact details can be found here:

http://www.rebmit.co.uk/architects.html

My project manager was Nick Reynolds nick.rey@zen.co.uk. Nick did a great job on the foundations and generally always being on hand to provide good solid advice. When building with new materials it's really important to find somebody who will take on new ideas, and use the web to research and communicate with the client/architect. Nick is also local to Frome which is also important when things need quick attention.

Both Paul and Nick were great at letting me have a go at things and helping out the amateur!

Sketchup is a great free tool for trying out ideas.

Whole house heating and ventilation

2006-05-20T08:01:00.001Z

Some things just feel right and this UNICO heating and ventilation system is one of them. I wanted something that ventilated the house because it is highly insulated & sealed, and I need something that also heated it. I didn't want underfloor heating (expensive and tedious to install and doesn't ventilate) and radiators take too much wall space and again do not ventilate.

The 1218 UNICO has one powerful radiator approx 12Kwatts in my case and a fan (silver box). This pushes the air down a plenum to the east and west of the house (mixture of alu tubing and rectangular fibre board). The heated air then comes out of multiple slots (just visible) in the fibre board ducts (the silver spiral tube is for hard to reach places like the media room). The picture shows an uninstalled cut down 'schematic' of the layout before fitting to the loft and ceiling.

Once the air has been 'stirred' in the room the return path is via the jungle and into the loft room where it is mixed at the white grill with fresh heat exchanged air.... and the circle of heating continues.

UNICO could not have been more helpful with advice and training. 10 out of 10.
www.unicosystem.co.uk

Shower ... yeah!

2006-05-17T20:37:00.001Z

A shower ... at last ... no more showers at my mother house. The thermal store is proving great. Really high pressure (3 bar) hot water without a noisy pump! More of a jet shower rather than a power shower.

I hate shower heads with pulse, massage etc. All seem like gimmicks to me. So I just went for a good quality head and simple thermostatic control. A good 'wet' shower is all you need. £89 for the thermostat & head from plumworld.com.

The tiles were chosen by my daughter and a friend. Problem is they are glass and that makes them really hard to cut in less than 1/4 sizes. When I come to finish the edges I'll make sure to make them whole tile sizes. No cuts.

Thermal store cylinder

2006-05-17T20:28:00.001Z

Hot water at last. Mother of all hot water cylinders arrives. It's a thermal store. Basically the hot water never leaves the tank. A hot water flow detector switches on a pump which draws the hot water from the top of the tank to the bottom via a heat exchanger. The heat exchanger transfers the cylinder heat to the in- coming cold water. Benefits:

a) (Drinkable!) mains pressure hot water, so no shower pumps
b) No hard water issues with tank
c) Hot water heated off peak with economy 10 and stored for use during the day
d) Really simple plumbing

Other features on this tank:
Solar coil which contributes to hot water and central heating
Boost button which just heats top 1/3 of tank in case you run short of hot water
Controller for heating pump and economy controls all pre wired
Simple DIY job (took 2 hours) to install and fill.

Got this from dedicated Pressure Systems www.heatweb.com. Very good build quality (which is more than I can say for the temporary boiler room door.)

Jungle space

2006-05-17T18:27:00.001Z

View from the south of the house. The walk way was done by my brother David. You can see where the Jungle will go. I'll probably put in a false floor with large holes for plant pots. Something for later.

The walk way will be finished off with decking to give an out door feel.

LED light bedroom views

2006-05-17T18:22:00.000Z

View from inside looking towards the girls rooms. Each have similar sized rooms (to prevent argument!), and each room is split level with a mezzanine floor over looking the jungle.

The pink light is a LED light developed mostly by my friend Patrick with a little electronic help from myself. Check out www.smoo.co.uk for the coolest LED lights on the Internet. Last thing I did with the light was control it with my Bluetooth phone. With an TV remote or BT phone, you just tap in what colours you want and change the mood of the room. The light can have different colours for down, side and up. Or you can just let the lights cycle through and pattens you like as fast you like. Better than painting the walls :)

The plants are just a few left overs - not the Jungle!

Big sky light

2006-05-17T15:45:00.001Z

The really big sky light goes in. 3m x 8m. Initially quotes came in at £15K, but extensive use of a hacksaw on standard alu bearers meant the whole thing (inc. k glass) was done for £6K and a lot of DIY.

Metal and lots of help from lonsdale .

The sky light provides light to the 'Jungle' in the middle of the house and 'solar gain' which is recycled around the house by a ventilation system which uses the internal configuration of the house to ventilate and heat the rooms.

In simple terms the outer thirds of the house have warm air pushed into them by the ventilation system locate in the 'loft room', this escapes from the rooms to the middle core and jungle area and is the re-circulated around the house (via a large internal loft window) using the ventilation fans ... and so the cycle continues.

A heat recovery system ads fresh external air (pre-heated by hot extracted stale air) into the loft room which is used as a mixing chamber for the ventilation system.

The inside shot is taken from the 'loft window' which is glazed just half way to allow the hot air from the skylight and rooms to be sucked into the mixing chamber (loft room).

Most of the money is buried

2006-05-17T15:38:00.000Z

Most of the money is buried under the ground. This is the storm attenuation chamber (looks like green milk crates, but can take 30 tonnes of weight) which can store a 30 year flood's worth of rain water in a chamber and then slowly release (using hydro brakes) into the main street drain. The chamber is about 10m x 1m x 0.5m in size. 3 other chambers and catch pits are located elsewhere!

Picture shows back filling before topping off the drive with tarmac.

The hydro brake is shown by the spare hand :). This releases storm water to the main sewer at the same rate as when there was just one house on the plot (currently three extra houses - hence the hydro brake)

Tiles and brick skin are being added.

Rear view and roof on

2006-05-17T15:28:00.001Z

A view from the rear showing the back entrances for bedrooms and the structure almost ready for brick skin and tiles.

The rear entrance's are so the girls can each have their own 'front doors'. With the open plan inside the house the idea is to add a little privacy into the coming and going to/from the house.

Roof goes on

2006-05-17T13:31:00.000Z

How to put a roof on quickly - 1/4 at a time!

I think Build it Green would have found it easier doing 1/8 at a time, but still the speed is impressive.

The construction of the SIP panel is clearly visible. 150mm thick of OSB FOAM OSB, which is then covered in breathable membrane, battened and then tiled. This create an amazing u value for the walls and roof, plus making the house totally sealed.

Care needs to be taken to ventilate the roof space. This is done with cross battens all 400m of them.

Glulam beams in place

2006-05-17T13:22:00.000Z

Some of the benefits of a SIP build are beginning to show. Just 3 weeks in and we are ready for the roof. No loft space means exciting ceiling space inside and chunky cross beams.

The SIP panels make a highly insulated house, and form the structure all in one process. Very clean and very quick.

Walls go up

2006-05-17T13:18:00.001Z

Amazing, about a week after signing off the plans local SIP builder Build It Green is delivering the pre cut panels to the site and starting to put them up. This shot is just a few days into the build. Hope to have the roof on in just a few weeks.

http://www.builditgreen.co.uk/
and some Interesting SIP links:
Wikipedia info on SIPS
Earthen Concepts SIP FAQ

Foundation and floor in place

2006-05-17T13:11:00.001Z

Another blog about building a house, but blogging is such a useful outlet for builders who can only think about one thing - their house.

Here is the block and beam foundation plate. Features to be added include a Jungle in the middle of the house, media room, steam room etc. All a long way off atm.

This was taken March 05. Metal straps have just been put in around the perimeter to hold down the Structural Insulated Panels (more later).

Size is 14m x 14m on a 30m x 30m plot. My brother who is building next door is in the background.