As we enter the home straight, I’m finding the prospect of living in a structure that is about 90% wood really uplifting. Our earlier concern that the house would end up looking like a sauna is now giving way to a serious ‘wow’ factor as the timber finishes go in. Already it looks, feels and smells fantastic.

The light and space of a contemporary design is a big plus on this north-facing slope. The airiness we’ve achieved with Passivent passive stack ventilation and the smell of so much timber in the structure and finishes adds to the pleasant sensory cocktail, as does the knowledge that we’ve minimised the use of synthetic materials. Even the minor touches like the Beam central vacuum cleaner make me feel this is going to be a relaxing place to live.

We’ve demolished the bungalow we were living in next to the house, really opening up the south side of the building to the sunlight. In the process we’ve converted about 50% of the garden to a mud bath.

The remainder was OK until we set about burying the ‘slinkies’ – the long, coiled plastic pipes that will fire our ground source heat pump. Digging two trenches 40 metres long is a challenge even in a big garden, but they’re in, and we console ourselves with the thought of virtually free heating and hot water once the system is commissioned. Manufacturer Viessman claim around 400% efficiency, meaning that for every 1kW we put into the heat pump it will extract 4kW from the ground. It’s a form of solar power, using the fact that the ground is warmed by the sun to a constant 11-13 degrees. This is sufficient energy for the heat pump to convert large quantities of water to 50 degrees. 

As I write in mid October, the system is yet to be fired up, but it’s not a problem as we’re finding our highly insulated house seems to stay at about 19-20 degrees without any heating apart from warm bodies, lighting and a bit of cooking.

We’ve started on the wooden walkway. The big task still ahead of us is the building of the front deck, which had to wait until the bungalow had gone and the slinkies were in.

We’re starting work this week, with the timber from Arbordeck already on site. It will really put the icing on the cake and ferry us over the mud while we wait for the grass seed to germinate. Months late, and virtually double our budget, the new Southernwood is finally approaching completion.

We’ve been working for over a year on the build itself and nearer three on the project. 100,000 nails later, what have we learned? I’d love to see more people self-building, and think it has an important contribution to make to more sustainable lifestyles, but it’s a real slog, and needs to be easier.

If you fancy giving it a go, here are Ben’s sustainable self-build rules of thumb:

1. Think of a number. Double it. Everything takes longer and costs more than you hope. The more you plan, the fewer surprises there will be, but you still won’t know exactly what you’ll find the day the spade goes into the ground.
2. Pay peanuts, get monkeys. Drive too hard a bargain withprofessionals and contractors, and guess what? They cut corners and you lose out. Trust is a rare commodity in the chaotic world of construction and sometimes it needs nurturing with cash.
3. Read ‘A Pattern Language’ by Christopher Alexander. You can get no end of advice on environmentally responsible building, but compelling literature about what makes buildings feel good is harder to come by. Alexander’s classic is a real source of inspiration, and worth a read even if you’re only tarting up a room.
4. Do the simple things. Not sure if you’ll be able to afford photovoltaics or a wind turbine? Insulate to the max and see if you still need them.
5. Go for timber. If wood were invented today, it would be hailed as a miracle material. You may not think of your house as a carbon sink, but build it with timber and it’s keeping carbon locked up for the lifetime of the house (and maybe longer). Wood is non-toxic, reusable, fantastically durable, good to work with and beautiful. How many plastic windows will still be working 200 years from now?
6. Push sustainability. Though there is no shortage of products and methods for more sustainable construction, they’re not mainstream, and most tradesmen, suppliers, specifiers, designers and inspectors won’t be familiar with them. Congratulations, you are now a one-person training programme for all of them!

<- Doors and surfaces | Useful contacts ->