As the noble Baroness, Lady Parminter, has already mentioned, the UK has signed up to the Paris agreement on climate change and importantly, we have our own national legislation—I declare an interest as a member of the Committee on Climate Change, established under that legislation—which commits us to reducing greenhouse gas emissions. In a few weeks’ time the Government are due to accept the fifth carbon budget proposed by the committee, which will commit us to reducing greenhouse gas emissions to 57% below 1990 levels by 2030—on the cost-effective path to our ultimate target in 2050.
At the end of June, the committee will publish its annual report on progress towards this target. The analyses are still going on, so I cannot leak the final results, but I can inform noble Lords of one fact that is highly relevant to this amendment. Last year—2015—emissions from buildings actually increased by 4% and, even adjusting for annual variation in temperature, the decrease was only about 1%. This is not a one-off. There has been very little reduction in emissions from buildings over the past 10 years. If we are to meet our legally binding obligation, emissions from buildings will have to decrease substantially, and at a much higher rate in the years ahead.
Part of the problem is that we have old building stock and many poorly built houses that are energy inefficient. This underlines the importance of not adding to the problem with new homes, when we do not need to. That is why this amendment is so important, not just for the short term, but the long term. If we do not require the zero carbon homes standard today, we will have to introduce it at some point in the future.
As we discussed in Committee, there are differences between what the Government are proposing and the standard in this amendment. For example, in the 2006 Part L requirements, the Government’s proposal amounts to a 44% reduction in greenhouse gas emissions, while this amendment suggests a 52% reduction for attached homes and a 60% reduction for detached homes. How would these greater reductions be achieved? An important element is on-site renewable energy generation—for example, by solar panels or other renewable sources.
As the noble Baroness, Lady Parminter, mentioned, there was considerable discussion of costs in Committee. We know now that from October this year in London, all new homes in future will have to meet the zero carbon home standard and the GLA has calculated that for a three-bedroom semi, the extra build cost will be between £978 and £2,702. For this additional investment to be cost optimal, the savings, discounted at an appropriate rate, should exceed the initial investment through the life cycle of the building. The calculations show that even with modest savings on energy bills of £100 a year, the investment would be cost optimal, and if the price of carbon is included—as it should be, according to the Treasury Green Book—the balance shifts even further in favour of zero carbon homes. The cost argument simply does not stack up if we take a life cycle view.
There was also a suggestion in Committee that making homes zero carbon would introduce an additional problem: if we make our buildings too energy efficient, they may be prone to overheating. It is true that one consequence of future climate change is that we probably will have to make our buildings more resilient to hot weather. However, this is not incompatible with zero carbon home standards. Professor Philip Eames of Loughborough University, an expert in renewable energy and building physics, says:
“The problem of overheating in new build can be an issue if the design is not appropriate ... we can quite easily improve the energy efficiency of new build significantly without suffering from this problem. It just needs attention to detail in terms of design”.
Finally, we have heard—as indeed the noble Baroness, Lady Parminter, has mentioned—that the requirement would be too onerous for small builders. Here, I would make the following observations. As has already been said, at least some small builders do not see it as a problem. Furthermore, given that one of the simple measures to achieve the zero carbon home standard is the installation of rooftop solar panels, it is hard to see why this is a regulatory burden, since it is a routine procedure. Even if the amendment would pose a challenge to some small builders, we should be asking them to up their game.
There are compelling reasons to accept this amendment, in terms of both our climate change commitments and cost effectiveness. The objections raised in Committee seem to me to not stand up to scrutiny. I very much hope that noble Lords will agree that this amendment should be accepted.