Personal story:

Originally I wanted to build a new eco-home but we also wanted to remain near family and friends and in the end we settled for renovating and extending our existing home, which we also extended so we could run a small bed and breakfast.

Motivations:

I first became aware of climate change when I read Mayer Hillman’s book How We Can Save the Planet and became aware of Aubrey Meyer’s ideas about contraction and convergence. This made me aware that something earth-shattering was happening and was the motivation behind the eco-renovation.

Key changes made:

The whole building is massively insulated with high performing insulation panels up to 170mm thick in places. The windows, doors and skylights in the extension are all wooden framed triple glazed units. Hot water for the central heating is powered by a mix of a new condensing gas boiler, solar thermal and a wood stove, managed by a sophisticated control system. Both the main house and guest area have heat recovery systems so we maintain a healthy, low-moisture atmosphere and don’t lose heat. We have a 4kW Photovoltaic Solar array which generates electricity when the sun shines. Rainwater harvesting provides water for flushing the loos and for the washing machine and garden. Finally, we’ve installed electric vehicle charging points to encourage our guests to come by electric car.

Measures installed in detail:

• Ceiling insulation – nothing on ground floor. Stripped plaster off first floor ceilings, fitted two layers of PIR between rafters, sealed with foam, then PVC vapour barrier, 30mm PIR on surface, taped, then finished with Gyroc
• Fitted 90% efficient gas boiler feeding a collector tank with heating controlled by RESOL programmer and TRVs on 90% of radiators
• Previous double glazed windows maintained
• External wall insulation –  plaster removed, wooden frame built with 70mm PIR fitted and sealed with expanding foam, plus 30mm PIR fitted on surface of frame with 12mm Gyproc finish, all taped, sealed and replastered
• Lifted floor boards, fitted two layers of PIR between joists, sealed with foam, then PVC vapour barrier taped on seams and boards replaced, with expanding foam around edges to seal
• Fitted a Johnson & Starley 80% efficient heat recovery unit in loft, taking heat from bathroom and top of landing. Fresh air back into bedrooms and living rooms. (Kitchen heat is used in extension heat recovery unit)
• Increased loft insulation to 400mm of rockwool
• CFLs throughout
• 4kW solar PV system
• 2.2m Solartwin solar thermal system on front roof facing due South, feeding collector tank
• New triple glazed back door and double glazed units in front door
• Underfloor heating in rear kitchen served from collector tank. Bedded in 70mm concrete with tiles above and 120mm PIR insulation below
• Water saving devices include; 3000 litre rainwater tank fitted under front driveway serving toilets in main house and outdoor tap. Low flush toilets
• Log stove with back boiler in living room feeding collector tank

Benefits of work carried out:

We moved out for a year while the work was done. The worst bit was the dust and stress but the best bit is the improved comfort of the house. Although we’ve doubled the size of the house and the price of fuel has risen we are spending no more on energy.

Favourite feature:

In winter the kitchen used to be an uncomfortable ice box but it is now a lovely space with a warm floor.

Common questions and answers for this SuperHome

Does your MVHR produce the feeling of draughts in the bedroom or living room?+

You can feel it cool at your feet, as the vent is under the settee with the insulated ducting routed under the floors. I don’t think I would call it a draught though. You can choose different speeds, if you felt it draughty. It’s usually pretty cool regardless of the outside temperature.

It would have been too invasive to rip up floor boards and deadening ash between the floors in all the bedrooms to lay ducting to vents in the downstairs ceilings. So the fresh air into the living rooms had to be taken from the MVHR unit in the loft, down a box section which I built, right down and under the floor boards downstairs, where insulated ducting takes it to vents which are screwed to the underside of the floor boards. These have open and shut sliding grills screwed down from the top of the floor boards, to allow us to control the air flow into the rooms.

My MVHR draws fresh air directly into the heat exchanger unit in the loft from a vent on the roof. It extracts warm damp air from the bathroom and warm air from the top of the landing, where the warm air naturally rises to.

Do you run you MVHR system 24/7?+

No, we run it mainly in the during bathroom use and some evenings, if washing is drying etc. When we are out during the day the heating is off so we leave the MVHR off. If we left it on then the net effect of leaving it on, would be to gradually cool the house.

It doesn’t feel stuffy when the MVHR is off. I think the big difference here, is that my house is an old one, with lots of compromises for practical reasons during the refurb. If it was a new build, with maximum air-tightness, I think there would be a big difference in our experience of living in it.

How did you insulate your stone walls?+

We simply looked for the best insulation values we could get without needing to have too much thickness, which would encroach on the room space, as none of our rooms are particularly large. Just now, PIR is the best option. It is also relatively easy to work with and seal all the gaps between the wooden frame and the insulation.

We essentially built an internal wooden frame/wall, filled with insulation panels, which sits between 25mm and 30mm away from the stone wall, to still allow the wall to breathe. 50mm would have been better, but it starts to eat into the room size again.

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