The government has decreed that all new homes build after 2016 must be zero carbon. This is easy to say, but quite difficult to put into practice for a number of reasons. Some are quite practical, for example getting the new building codes and the new building methods and technologies right. Some are to do with the building industry itself, which will have to change the way it operates in a world where designs have the over-riding constraint of energy-efficiency, but the most important consideration will probably be price. Put simply, how much more would you pay for a zero carbon home? Would you, for example take a new zero carbon three bedroom home over an older, less efficient four or five bedroom property? That would imply that the incremental cost of zero carbon was several tens of thousands of pounds, a price that most people would probably not pay. Of course, the number may be less than that, or technology may make for a better payback from energy efficiency or micropower. At the moment there is no real economic case for the routine installations of things like solar panels or CHP, or other measures that require thousands of pounds upfront and take a very long time to pay back on the investment. That doesn't mean that there are no cases where they make sense, but not for every house on every street. If the technology improves then that might change radically; there are some very interesting things going on in thin film solar for example, and the government must be hoping for such advances in time for 2016.
Here in Basildon we are, as ever, leading the way, with a small development of zero-carbon public housing. We hope that it will be an exemplar to show what can be done today and to explore the economics of zero-carbon with the most up-to-date technology and methods. However, the critical number will be the cost-per-unit of this approach. If it comes out at too high then that will be a warning sign. Houses are unaffordable enough as it is without putting a further premium on new properties, especially as any increase in price will apply after an arbitrarily fixed date. This is probably why the current government put it comfortably far in the future.