Wednesday, 9 March 2011

Budget and payback

It is about time I talked about how much all this is costing. So far we have managed to keep close to our estimated budget and schedule. At this point, it is looking like the build costs, excluding VAT and professional fees, will come out at £1500 per m², which, given that we are having a high standard of internal finish (hardwood floors, granite worktop, decent taps and appliances etc) is not unreasonable. If you strip out the Passivhaus elements, it would have costed £1200 per m².

I think we have learned a lot about how we will approach new Passivhaus builds to bring the cost differential as close to £0 as possible. This is something we are looking at now. For this project, the extra cost will pay for itself easily over the time I hope to be living in the building, especially now that fuel prices are shooting up - very small increases in energy prices have a disproportionate effect in shortening the payback period. There will be many other non-energy benefits for us - better air quality, much more comfort (no cold drafts or 'cold radiant') and less noise from outside, no radiators on the wall taking up valuable space, loads of natural light, cooler summer temperatures - I think all those must be worth something.

Other Passivhaus Refurbs

Passivhaus refurbs are like London buses, you wait for ages for one, then suddenly three in a row come along. The other two projects are both part of the Retrofit for the Future scheme.

First, is the Princedale Road refurbishment of a Victorian Terrace in Holland Park, West London. The building is owned by a social landlord, Octavia Housing. It gained its Passivhaus certification on 1st March from Peter Warm, making it officially the UK's first refurbishment to reach the full (15kWh/m2.a; 0.6 ach @+-50pa) Passivhaus standard. It is a fantastic achievement, particularly as the building is a mid terrace in a conservation area, so there were many complex problems to overcome.

The second project is here in the south west. The client is North Devon Homes and the project, known as Barbrook, is currently on site. The site is much more challenging than our one so that, even though they are 'only' going for the EnerPHit standard, their project is every bit as challenging. I am looking forward to visiting Barbrook soon.