OK. Before we begin to get into the nitty gritty of the project let’s take a moment or two to set the context. There are a number of questions floating about that help to set the scene, let’s look at some in statement form.

“The earth is getting warmer, and that is caused by mankind.”

I’m not even going to enter into this debate. You can have your own view, but as far as this project is concerned it does not matter what is the right answer. It will still, for the foreseeable future, get warm in the summer and cold in the winter. I’m attempting to ensure that this dwelling will be capable of operating at low cost over the likely range of temperatures and humidity.

“We are running out of oil (or hydrocarbons in general)”

There is plenty of evidence that this is more likely than not. Global industrialisation is spreading, and with it significant energy use is expanding. Oil exploration is still bringing in new discoveries, but at greater cost and in more difficult areas to exploit. As for the UK our local discoveries are getting close to exhaustion and we will be facing greater competition for the reserves that can be exploited. Prices will inevitably rise.

“Renewables are the  answer, in Britain we have some sunshine and loads of wind.”

This is a National issue, not one for the individual. Individual wind generation is totally uneconomic. The amount of power generated by an acceptably sized wind turbine in a normal domestic environment will never even recover the energy used in its manufacture. On a National scale, these sources require huge investments and are subject to fading away when really needed so necessitating some form of base load generation to keep the supply running. But I digress, the point is that it is well outside the domestic scop of this project.

If these questions intrigue you, as they did me, then I recommend you download the free book written by David McKay “Sustainable Energy – without the hot air” where he explores these issues in a down to earth way with real hard numbers. See www.withouthotair.com

Local energy issues

“Domestic energy is only a small proportion of the national total.”

In one sense this is right. Domestic energy is just over a quarter on the national consumption, around 27%. Another 20% or so goes on our individual choices of other things, specifically transport. The remainder is consumed by business and government supplying the goods and infrastructure for citizens.

Again, this project cannot concern itself with these global issues. Even the matter of transport, based on personal choice, is outside the scope. We can concentrate only on the 27% that we can influence.

“There’s not much you can do with an existing building.”

Well now we are getting to the point. As mentioned in an earlier post, it is much easier, and a better use of money, if you are to start form scratch. But that implies a lot of embodied energy going into a new building. But is the main structure is there and reasonably sound then we need to do something with it to reduce its energy consumption. At the same time we will almost certainly increase the comfort as well as reducing the costs.

“Turning down the thermostat by 1C saves a bunch – wear jumpers more.”

Turning down the thermostats does, all things being equal, reduce the energy consumption. It’s all to do with energy leakage which is dependent upon temperature difference. However, having tried it last winter, it does make for a not very pleasant living experience. And it’s plain to see that the older one gets the more one feels the cold. So the drive must be to reduce the leakage so that the temperature can be maintained at a comfortable level at far less cost of both money and non renewable resources.