Eco housing stuff - terribly boring really

[El Pibe]

Thanks for all the advice and wishes of luck everyone, I'm sure we'll need it but I'm feeling a little less like I'm floundering in ignorance now.

[katie1997]

El Pibe - great project, not boring at all and doing it this way as a new development will help reduce costs. Insulation = key. I would hope that at least your architect knows about thermal briding tho.

Solar PV does not need direct sunlight they are capable of generating some electricity on cloudy days.

Micro CHP is still powered by mains gas or LPG, which is very expensive in rural areas. Biomass waste wood chips/pellets/logs worth thinkgin about.

Choice of air/or ground source heat pumps would be dependent on your heating demands and what other heating you have (eg air to air ones don't provide hot water, do you want underfloor heating at low temp over long period of time etc). Air source is easier to install than ground source but this may not be aproblem in your case.

For generation, mini wind (needs a detached property) but costs would be huge and not related to what it delivers.

Check if there are any financial incentives for investing in new technology which may help and good luck! am going to send you some links too which should help you to choose.

[LadyDeliah]

These guys are brilliant; Centre For Alternative Technology.

They do short eco building courses and have loads of books and pamphlets for sale.

I have been to visit the site loads of times since I was a kid and still love going there.

They are very inspiring.

[Senor Chevalier]

Am building a house at present and looked into all this.

Short summary is that the "cool" eco technologies generally didn't stack up whereas the "boring" ones did, i.e. insulation.

Ground Source Heat Pump GSHP

Waste of time when I looked at it. Coefficient of performance of 3-4x. This means for evey unit of enery used driving the pump you get 3-4 units worth of heat back. So far so good. However, driven by electricity and transmission losses between generation (power station) and point of use approach 75% so net net you have not really gained anything when compared to an efficient gas boiler.

Gas - no transmission losses, decent condensing boiler c.95% efficient.

I think it could be justifiable if you were using PV solar panels to drive the pump, but this only stacks up if you are a net generator of energy, i.e. you can power all your other kit and kaboodle and there is a surplus for the GSHP.

GSHP does make sense in remote locations off the gas network where the alternative is electric central heating. In this limited case you benefit from the 3-4x COP compared to electric heaters. i.e. it allows you to recover to being as efficient as gas...

Solar Panels and Feed in Tariffs

Complete nonsense in this country IMHO.

The embodied energy in producing and installing these things can outweigh the carbon saving from electricity generation. The environmental argument is certainly thin. The economic argument is easier with the feed in tariff but this is questionable from a social perspective. Basically energy companies are allowed by the regulator to operate at a certain profit level. If customers install solar panels then the energy company pays them for the energy they generate (even if they use it and don't export any energy back to the grid) and so they get to charge the other customers a higher rate so that they make the same overall profit. So you are basically stealing from your neighbours and generally cash rich people can afford the panels whereas poorer people don't have the option. Anti social behaviour total green washing without any substance behind it. Save the planet and the hassle by just stealing things from your neighbours.

Insulation and Passivhaus

Genuinely very good idea and makes sense. Super insulate your house (e.g. timber frame with 300mm insulation. Tape and seal the whole house so it is totally air tight. Triple glazing with special coated glazing. Eliminate thermal bridging. Exhaust air heat exchange so all air changes in the house go through a heat recovery system rather than trickle vents on doors and windows. All seems to stack up.

As mentioned above, hard to retro fit. Best designed in up front.

Thermal Solar Panels

Basically hot water in black sacks on the roof. Next best thing to spend money on after insulation. Seemed to stack up. Downsides are too much hot water in summer and not enough in winter but still probably worthwhile. Comes into its own if you have a pool as you need a heat sink to dump excess hot in and this heats the pool in Summer when you want it most.

Good Luck, sounds like an ace project. Building in London absolutely sucks.

[El Pibe]

Good advice SC, thanks for that.

We are pretty remote so are almost definitely going with SPV, hopefully we can get some pretty decent output as we have a lot of surface area to work with.

Everyone in that part of the world goes with oil burners which is something we're very keen to avoid if possible for a whole host of reasons about cost (present and future), sustainability, energy security and of course carbon footprint.

[JMT]

My husband is a Certified Passivhaus designer. Maybe he could help - 07932 717 064.

[mynamehere]

I'll add my 2 p: Dig in into the ground so the roof becomes a wild flower hill. Ground source heat. Facing south. Entirely triple gas filled glass front. Wind turbine off to the side. I'm 50% solar generated hot water and electricity on a mid terrasse wrong facing house. Lucky you to build. Look at all the German prefab fab stuff.

[El Pibe]

Much as I love some of the wackier stuff out there, we are quite limited in how zany we can be as the original farmhouse and outhouses are listed and basically need to end up looking like they do now...only without the rotting crumbling ex/interiors obviously.

[giggirl]

Well done. My house has been insulated to within an inch of its life and powers itself (very efficiently) off solar energy panels. Not sure about any of the technical specifications. The house is very warm and I don't get big energy bills. Nice.

[El Pibe]

Can I just say a big thank you to Ruairi firstly for the above freely offered advice, and subsequently for the passive report, calculations and patient advice to myself and La Piba. We now have a much clearer picture of where we're headed with all of this.

If anyone else is thinking of doing similar things and is thinking of talking to someone, he now officially has the El Pibe seal of approval ;)