Eco home

[veggiechicken]

A house has just been built down West in the village with a ground source heat pump that is below the water table -so the incoming tide is constantly replenishing the water - as a heat pump can drain all heat out of the soil over time. I know what I mean - even if you don't!

[Tripmeup]

I built my own home and am living it approx 2.5 years now.....

I did alot of research when building as I wanted to keep it as warm as possible for as liitle cost as possible....

So, I went for an air-tight type of approach where there are no wall vents and all breaks in the "continous" air tight barrier had to be sealed etc before moving onto the next stage..
I taped up all windows etc with an air tight tape, applied an airtight scud plaster to the walls before puttting insulated boards up etc etc....
I also put in an airtight membrane where needed and so on....

The idea was to keep the heat in and the cold out....
Ventilation is achieved using a Heat Recovery Unit and I also have Solar for water....
....and then an efficient oil boiler for the wintery times....
I did a few other things like extrenal air supply to my open fire, which strictly speaking goes against the more stringent ideas/views of air-tightness, but we really wanted an open fire too....
There are lots of other bits and pieces I did but could go on for ages and work calls...

If anyone has any questions, just ask and I will answer if I can...

[chris]

Ya... pics?

[PyreneesPlot]

We too built our own house and have been living in it for nearly three years now.... Its almost finished.

We originally wanted to go solar passive, ie no heating just relying on solar gain, but then discovered that even here the sun doesn't shine all the time We rejected a heat pump - too expensive for us and the end have gone down the old fashioned route of loads of insulation. The house is built out of super efficient clay blocks which have a minimal mortar layer between them, which is where most of the heat is lost in the walls.

Think about the volume of rooms - lovely oak framed vaulted ceilings may be harder to keep warm than lower ceilings and smaller rooms. We looked at a number of timber frame options and rejected them partly for this reason. We have no heating in our bedroom, but it stays warm with us in it due to insulation and being a small volume. And Mr PP's hot air of course

Our principle rooms face south with large windows, the north side only has two small windows. Heating come from a small 7kw log burner which warms the whole house (102 sq m), using only 1.5 - 2 stere a winter. We are very lucky to live in a heavily wooded area and get a share of the commune's wood - although we do have to cut down the trees and process them entirely our selves. But €80 plus chainsaw fuel will give us fire wood for 6-8 years

We lived off (elec) grid for just over two years, with PV solar panels which charged up batteries for use when the sun didn't play (night!). This did not give enough power to run a normal fridge, so we used a gas one and we had to use the genny for running the washing machine. Power tools for the build could mostly be run off the panels on a cold, sunny day. We had one grim ten day period without enough light/sun to charge up the batteries so were reduced to using lights only - no TV, computers, couldn't charge the phone etc or use any appliances without the genny. We have gone on grid mostly because the batteries were close to the end of their naturel life, having been begged from an industrial plant that was replacing them. The cost of replacement was huge and batteries are not very eco, whatever drivers of the Prius may tell you.

We are not in a position to sell back so use all excess power to heat the hot water tank, meaning most of our hot water is free. Both washing machine and dishwasher take the hot water so don't need to heat water.

Self building is a fantastic experience, stressful and rewarding. It can be cheap, especially idf you can do things over time. Just don't try and build and live in it. We moved into the shell and it was grim at times.

Same as Tripmeup - any Qs just ask!

[Glutton4...]

Any questions? Yes, thousands!

During your plan and build, you probably already asked and answered any I could come up with, so feel free to just answer them as they come back to you!

[PyreneesPlot]

Any questions? Yes, thousands!

Mostly are we mad?

And why, why why?

[Glutton4...]

The answer to the first is; No, perfectly normal.

The answer to the second is; Why not!

[Mikey]

My Next door neighbour is in the process of building a double storey open plan living room, and we've discussed at length the pro and cons of heating the space.

With the timber frame I'm looking to create a double height central atrium and stairwell which would have bedrooms off one side and living space off the other. I can't show you pics cos its all in my head.

tripmeup could you not have gone for a woodburner on a flue instead of an open fire, wouldn't that have been a sealed unit then? I've been looking at wood boiler burners or back burners as some might know them. Burning logs heats water via gravity and feeds the hot water cylinder.
I've considered as part of the insulation process painting the walls with a ceramic ball paint which reflects heat back, we use it with underfloor electric heating to stop the concrete slab absorbing the heat from the cables. Its not that much more expensive than standard paint.

[veggiechicken]

Mikey, I've just been to the eco house I mentioned earlier, designed, built and lived in by a husband and wife team of architects. It was very warm in there but the only heating is a log burner. This heats water which goes into a thermal store and underfloor heating (up and downstairs) is run off this store. They use wood from about October to March - then the solar panels kick in to heat the store. At the rear of the house is a two-storey sunspace - fully glazed - that captures the heat from the sun, or acts as a buffer from the outside. So, if its 0 outside, its 10 in the sunspace and 20 indoors. The heat from the sunspace is circulated around the rooms by sliding doors and windows at both levels. So heat can come out of the main house, go into the sunspace, rises to the first floor and is channeled into the upstairs.
There's a lot more to it than this! I've watched it being constructed over the last 6 years. If you get to a point of being really interested in how to start, I'm sure they'd show you around. Its near Abergavenny.

[Tripmeup]

Hey Mikey..yea we could have and I was swaying that way but herself really wanted an open fire..so we went with that for now....I did as I said put an external air supply from outside to it, so at least its not sucking the warm air from the room... see Baxi burners for more info
As I said my aim wasn't to build an eco house per se, moreso a warm house with as much consideration towards natural energy as possible...
I do find the Heat Recovery to be a great benefit with a real freshness to the house and its never felt stuffy

[maytreefrannie]

Can I ask a (maybe) unpopular question? How does it work out for cost? I once read about installing solar panels and double or triple glazing. The writer was very happy with the result and gave the cost plus the savings they were getting and could expect to get on heating etc. It worked out that it would take 15 years to pay for itself on the figures given. Is this the case?

Of course, selling to the grid might reduce that recoup time. I'd be interested in what other grapes found regarding this - not looking for prices or figures, just how long the projection would be for savings to cover cost.

[veggiechicken]

I've had solar panels for about 3 years - they were quite expensive then but the Feed in Tariff (FIT) was also more generous. My investment (about £10k) will be paid for in about 9-10 years (less if the price of electricity continues to rise) and the FIT payments will be made for 25 years - but I'm unlikely to be living in this house until then!
Any new windows these days have to be doubleglazed as a minimum (I believe) so opting out is not an option. I've replaced all my windows with double glazed but couldn't put a return value on them.

[MartinRSharpe]

I don't think it is really an unpopular question. Any environmental improvements must be weighted pros vs cons. Cost is obviously a negative aspect, for some improvements the short or (more often) long term savings outweigh this.

The biggest savings will usually be made primarily from the heating related areas of the house. About 50% is convection, 40% conduction and 10% radiation.

Therefore the place to start within heating is the convection, so draft proofing doors, windows and if they are not used chimneys (with something like LECA) or go the full way and install an MVHR (Mechanical Ventilation and Heat Recovery).

With the MVHR another benefit is that all the air is filtered. Basically the house is pretty much airtight except for these ventilation system which has a filter on it. If you have a member of the family that suffers greatly from hay fever this can be a rather large benefit!

Of course the downside being it costs £4-5K and requires ventilation pipes though the house.

With all "eco" considerations I would encourage you to look at the passive side before just going out and buying an active bit of technology.

[Mikey]

I'm currently looking to install a wood burning boiler stove, into the space of our open fireplace. Its a broseley evolution, I can burn wood in it and heat water to fill the heating system at the same time, hopefully saving on our oil use. The benefit of this wood burner over others is it connects to my existing combination boiler, via a kind of manifold. I've got a bit of techie details to do so I can work out the comparable running costs.

[veggiechicken]

Won't you need a thermal store (cylinder) for the hot water Mikey? That was one of my problems - so I ended up having the boiler converted from Combi to System and having a solar thermal panel on the roof with a cylinder. Skipped the wood burner/hot water as too complex for this house.