Upgrade all homes to EPC C

Posted on By Anne Miller

Heating buildings accounts for 21% of the UK’s carbon emissions, and everyone, from Insulate Britain to the Government agrees that improving the energy efficiency of our homes is important: it cuts carbon emissions and bills while improving health and comfort.

The Government’s recent Net Zero Strategy and Heat and Buildings Strategy, as well as the Cambridgeshire and Peterborough Independent Commission on Climate’s (CPICC) recent final report, all highlighted the benefits. However the difference in the level of ambition is really stark.

Deeply hidden in the Net Zero Strategy is the surprising aim that the demand for heat in buildings should reduce by just 15-20% in the next 30 years.  This is about half the difference between an EPC D and an EPC C.

This is nuts, because the energy performance of the UK housing stock improved by this much in the 5 years between 2010-2015.  The rate of improvement then dramatically slowed, following the policy changes after the 2015 election, the failure of the Green Deal and the long wait for its replacement. It took until 2019 before the rate of improvement resumed.

figure 12 from Heat and Building Strategy, October 2021

In contrast to the Government’s feeble proposal, both the national Committee on Climate Change and our local CPICC, recommend that 99% of homes should be improved to EPC C or above by 2035.

Carbon Neutral Cambridge projection of potential route from today to 99% EPC C or above

They also propose that all new homes must be built to substantially better than EPC A from now on (as proposed in the draft Greater Cambridge Local Plan)

This is a very sensible proposal, as it would put us on a clear path to net zero.

Carbon Neutral Cambridge has estimated the impact that upgrading EPC’s would have on the energy used for home heating. Although there are a number of simplifications in the calculations, this suggests that it could reduce the demand for home heating in the Combined Authority area by 35% by 2035, and by 70% by 2050.  This is shown in the graph below.

CNC estimates, based on typical energy use (kWh pa /m2) and the changing proportion of homes at each EPC level, comparing the Committee on Climate Change’s recommendation with the target in the Net Zero Strategy

The upgrades should also be a good financial investment: As a figure in the CPICC report shows, the most common level of energy performance in the Combined Authority is EPC D.

Figure 5.2 from CPICC report October 2021

Improving from this to EPC C is not too disruptive to do: typically, it involves having good double glazed windows, a good level of loft insulation, draught proofing, and filling any cavity walls with insulation. The English Housing Survey estimates that it costs between £1,000 and £5,000, depending on the condition and age of the house. They estimate that the average cost of upgrading the whole housing stock is about £8100 per house.

Encouragingly, for those wondering if an investment of a few thousand pounds can be justified financially, evidence from a Cambridge University study commissioned by BEIS indicated that properties with an EPC C rating were worth around 5% more than the equivalent homes with an EPC D rating. As this is a £25,000 uplift for the average Cambridge house worth £500,000, investing in making your home more energy efficient will usually be a good deal.   It also helps de-risk the future: not only does it help insulate you from future energy price rises, once a home has been insulated to EPC C, it will be much cheaper and easier to install a low carbon heating system such as a heat pump, once gas boilers start to be phased out.

Seems like a no-brainer to me!

Based on article first published in Cambridge Independent October 2021

Getting off gas

Posted on By Anne Miller

The United Nations’ recently published report on the causes and consequence of climate change was alarming. But it did also clarify the importance and benefits of reducing methane emissions.

Carbon Dioxide (the main cause of climate change) and Methane (which is the main component in Natural Gas) behave in different ways:  Methane is a much more powerful greenhouse gas than CO2, with around 100 times the short term climate impact between now and 2040. However, while the CO2 that we emit now will be around and continuing to warm the planet for centuries (unless we invent and deploy vast quantities of hugely expensive machinery to capture it for us), the methane we’re emitting now will decay and disappear naturally within a few decades.

Despite this short lifetime, Methane has caused about 30% of the warming we’ve seen to date.

Figure SPM2 from IPCC summary for policy makers, 6th assessment report August 2021

This gives us an opportunity.  Stop emitting methane now: the methane levels in the atmosphere will start to fall naturally, and we’ll win precious extra time to decarbonise everything else and avoid disaster.

The main sources of methane in the UK are leaking natural gas from pipelines and drilling sites; burps and manure from cattle; and decomposing waste in landfill sites.

Encouragingly Tianyi Sun, a climate scientist at the US Environmental Defence Fund calculated that using existing technologies—for instance, by capturing leaking methane and better managing agricultural manure—we can halve methane emissions by the year 2030.

Despite the resistance from the fossil fuel industry, we should definitely stop drilling all new oil and gas wells, and urgently stop using gas for heating and cooking.  In parallel, we need to slash leakage from gas pipelines, processing plant and drilling sites (including disused ones which can continue to leak for decades). These leakages can have a surprisingly large effect.

The operator of Cambridge’s gas network, Cadent, estimates in their annual report that 0.4% of the gas leaks out from their distribution network, mainly from aging cast iron pipes. There are similar losses from the North Sea gas platforms , even though researchers report that much of this is ignored in the government’s figures. Worryingly because methane such a powerful greenhouse gas, if even 1% leaks out before being burnt, that would double the carbon footprint of using gas. As Cambridge’s gas network is old and quite leaky, gas leakage could even be the largest single contributor to our climate impact between now and 2040.

So when you see a Cambridge street that’s being dug up, yet again, to install big yellow gas pipes, it may be annoyingly disruptive, but it helps to know how important this is for getting us to Net Zero.

Based on article first publish in Cambridge Independent, August 2021