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The Surprising Impact of Small Changes is What We Need

Fossil fuels are at the intersection between the climate crisis and geopolitics; contributing to the transition to renewable energy will serve two purposes. After a long reflection on what to do against the war in Ukraine and climate change, about a year ago, we decided to work on accelerating the phasing out of natural gas from UK homes. changes

Why gas boilers?

The Surprising Impact of Small Change is What We Need unagru architecture urbanism ecological sustainability

Today, 95% of UK homes are centrally heated, relying on gas or oil-fired boilers.

There are 26 million gas boilers in the UK, each emitting 3.5 tons of CO2 annually on average. The combined 90 million tons is almost double the emissions of all our power plants combined. Gas boilers are also dangerous emitters of carbon monoxide, which can be lethal indoors, and Nitrogen Dioxide (NO2), particularly dangerous in cities. Clearly, we want to get rid of them.

Boilers are replaced every fifteen years at a pace of 1.7 million annually. Only a fraction of these, about 60 thousand, was replaced by a heat pump last year: less than 3%. It would take four hundred years to complete the transition at this pace.

Surely someone is doing something? Yes and no. The government has rightfully approved a ban to gas boilers in all new build homes starting in 2025 (better late than never). The decision is really a no-brainer: new buildings built to decent efficiency standards are perfectly suited for heat pumps.

What about existing buildings and boilers? Here, governments are less proactive. In the UK, a ban on gas boilers is expected to take effect around 2035, so we will have gas boilers running until 2050. Incentives to replace gas boilers are limited to heat pumps, which are a great alternative but not always viable and usually expensive. Scientific orthodoxy on sustainable buildings prescribes focusing on the building’s fabric (wall, floor, roof and windows): to make buildings more insulated and airtight (retrofit), thus reducing energy consumption. This makes sense in many ways: firstly because not consuming energy in the first place is the best way to reduce carbon emissions. Secondly, saving energy saves money.

But there are downsides to this policy. Retrofitting buildings, particularly old ones, needs to be done with care and can be expensive, depending on the improvement we seek. Secondly, retrofitting can be wasteful and carbon-intensive. It often entails demolition and reconstruction of parts of the building, new windows and doors and other invasive interventions, bringing forward costs and emissions. [1]

Finally, there is an opportunity issue: not always people have the money, the time and the expertise available to carry out a retrofit project. On the other hand, we have 1.7 million boilers being replaced every year. This is an opportunity in itself that we should not waste. In our opinion, incentives should be tied to upgrading or retrofitting the building fabric and replacing gas boilers with electric alternatives. More importantly, we need a branch of research and government policy that tackles the boiler issue separately from the building’s efficiency. If we do so, we suddenly have 1.7 million chances every year to reduce carbon emissions, urban pollution and several other risks related to gas boilers.

The electric grid

Another argument in favour of gas boilers is their supposed efficiency. Luckily, in time, boilers have become indeed more energy-efficient and some argue that replacing them with electric alternatives would only shift the emissions from the boiler to the gas power plant that produces electricity. Traditional electric heating technologies are less efficient than gas in converting energy to heat. But both arguments are no longer valid.

A study from the Carbon Trust projecting the carbon intensity of the UK’s energy grid in time shows how even traditional (supposedly wasteful) direct electric heating will emit less carbon than gas boilers from 2025. If we sum these emissions over fifteen years, direct electric heating would already save carbon dioxide. Secondly, direct electric heating is not the only solution: many smarter, more efficient options today further reduce the cost and carbon intensity of electric heating. We have investigated these new technologies and integrated them into our suggested solutions.

The Surprising Impact of Small Changes is What We Need unagru architecture urbanism ecological sustainability

Fuel poverty

Finally, fuel poverty is probably the most difficult topic to discuss here. For several reasons we will discuss further in other articles, gas prices have been kept artificially lower than electricity prices. In this context, gas boilers tend to be more economical than most electric alternatives.

In other words, fuel poverty is related to regulatory and economic policies. It should not be up to us to perpetrate market distortions by advising against electric heating. Most importantly, the market distortions will be corrected in time, and electricity will progressively become cheaper than gas.

It is impossible to forecast these variations into the next fifteen years. We suspect that a boiler installed today will end up costing more to run than electric alternatives when we factor in its entire lifespan. More pragmatically, not everyone will want to invest in electric heating in the short term, but some may be willing to spend more for environmental purposes. Finally, newer, smarter technologies, combined with energy grid price variations, claim to match the running costs of a gas boiler. We think we should provide information about the alternatives and let everyone decide.

Our first goal

A little more realistic and down to earth, our goal first goal is to eliminate one thousand boilers: by helping people choose alternative solutions. From there to 1.7 million, it's going to be a breeze :).

[1] We believe a pragmatic and effective approach would be combining retrofit and new heating technologies. Ideally, we would have time, money and expertise to carry out a deep retrofit of the building and install an efficient electric heating system. In other cases, we would combine lighter improvements to the building with new electric heat engines. Finally, in some cases, we need to accept that there is no opportunity for a retrofit at this time, but we should still aim to replace the boiler with an electric alternative.


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