- Email: [email protected]
Home of tomorrow
News Insight Net-zero carbon
Home of tomorrow Radical plans are set to slash the carbon emissions of UK homes. Will people accept them, asks Adam Vaughan GAS boilers make for an unlikely UK election battleground, but politicians have been competing on who will phase them out the fastest. Last week, the opposition Labour party said it would make all new homes net-zero carbon from 2022, beating the Conservative government’s plans to rule out gas boilers from new homes by 2025. The Liberal Democrats in turn said they will make new homes net zero by 2021. Whoever wins next month’s election, the flicker of gas boilers is long due for extinction. The UK’s 26 million homes are responsible for about a fifth of the country’s carbon emissions, making the greening of them a key plank of slashing net emissions to zero by 2050 – now a legal requirement. Retrofitting those buildings will be a huge undertaking (see “How to green your home”, opposite).
running costs roughly equivalent to those of gas boilers. However, doing away with a gas connection means a financial saving both to society – because the cost of connecting the home to the pipe network is paid through everyone’s energy bills – and to the owner of the home, because they will no longer need to pay the gas standing charge that energy suppliers impose.
1
2
3 8 4
6 7
5
Homes that are net zero when it comes to carbon emissions will require many features that most current homes lack
New build Meanwhile, some 230,000 new homes are built in the UK every year, most of them reliant on fossil fuels for heating and hot water. That will radically change with the government’s recent future homes standard, which will apply to England from 2025, and could be followed by similar rules in Scotland, Wales and Northern Ireland. What will new homes then look like? Ministers hope the building regulations mean an average home’s carbon emissions will be 80 per cent lower in 2025 than one built to today’s standards. To reach that goal, the government isn’t explicitly banning gas boilers, but is implicitly ending them by proposing a reduction in home CO2 emissions that would be impossible to meet with one. Crucially, a home’s source of heat will have to be low carbon. 18 | New Scientist | 9 November 2019
1 Green roof
5 Ground source heat pump
2 Timber frame construction
6 Induction hob
3 Insulated walls and floors
7 Air source heat pump
4 Car charging point
8 Double glazing
For some, such as blocks of flats, it may come via a heat network, where a central boiler pipes hot water to every property. That is still likely to involve fossil fuels in the near term, but a central system is much more efficient than a block full of individual gas boilers. For many homes, the answer will be a heat pump – effectively a refrigerator in reverse – which uses a fan to extract heat from the
80%
How much lower the carbon emissions of new homes in England will have to be
ground, water or the air, even on a cold day. Most will be air source pumps, which involve a box like an air conditioning unit on the home’s exterior. Like a traditional boiler, these pumps can be used for hot water or space heating, so the inside of future homes won’t look much different. “It’ll have bigger radiators, running on lower temperatures, but otherwise it will look pretty much the same as a house today,” says Jenny Holland of the UK Green Building Council. There is a cost: heat pumps are about £3000 compared with about £1500 for a gas boiler, and they consume electricity, with
Changing behaviour Jenny Hill of the Committee on Climate Change, which advises the UK government, says the switch to heat pumps is likely to require some adaptation. “It does absolutely require behaviour change. We don’t currently know how people are going to react to not being able to install gas boilers in their homes.” For one thing, gas cooking hobs will be replaced by induction hobs, which are not only more efficient, but can now match gas for responsiveness when it comes to turning the heat up and down. “But they do require you to have COPY SUBis some a new set of pans, so there inconvenience there,” says Hill. PAGE SUB It isn’t just boilers: the fabric of future buildings willpress be OK for transformed (see diagram). Their walls, floors and roofs will have to be much better at retaining heat than today’s, and they will need high-performance windows. Homes will have to be airtight, but still well-ventilated. Richard Lowes at the University of Exeter, UK, says walls are likely to look the same, but have more efficient insulating materials inside them. With windows, double glazing is so good now in performance that triple glazing is unnecessary. Other potential changes include a growing use of timber frames for buildings, which
tomorrow house_091
Working hypothesis
More Insight online
Your guide to a rapidly changing world newscientist.com/insight
lock-in carbon, and “green roofs” covered in vegetation, providing a natural form of insulation to reduce energy consumption. Although 2025 is the key date, the government is proposing an interim strengthening of regulations next year. That won’t force the switch to greener heating, but promises a cut of 31 per cent on carbon emissions and more than £200 off average annual energy bills for new builds, versus rules today. Solar panels, already on the roofs of nearly a million homes, would be one way to do that, officials suggest. Hill says there is definitely a role for solar panels, but they are no substitute for a low-carbon heat source. “You have to look at how you decarbonise your heating and that is what delivers the bulk of your savings.” Home battery storage devices, which can store electricity from solar panels and exploit off-peak energy tariffs, are expected to be niche initially and are unlikely to be standard in new homes. “It comes down to the economics:
batteries are expensive. You don’t need solar power or a battery but it’s nice to have,” says Lowes. The Home Builders Federation trade body says it welcomes standards on carbon emissions, but argues that the government’s
“We don’t currently know how people are going to react to not being able to install gas boilers” proposals would be very challenging and require a lot of work on supply chains. Such concerns can have an impact. In 2015, the government shelved zero-carbon home standards a year before they took effect, in a sop to developers. Hill questions why the UK construction industry should find the rules a challenge, when a gas-reliant country such as the Netherlands has already introduced rules banning gas boilers without it causing problems. “From our perspective, we believe the technology exists now
Sorting the week’s supernovae from the absolute zeros
to build homes that are net-zero compliant, water efficient and don’t overheat. The problem we have is with the skills and industry.” Compliance regimes for new homes, enforced by thinly stretched local authorities, aren’t fit for purpose, she adds. Hill also believes that the new standards should be introduced before 2025. Still, the future homes rules have been broadly welcomed, even if they could be tightened up in places. “There’s a general thing here about moving away from fossil fuels, which is to be applauded,” says Lowes. There may be grumbles in some quarters about induction hobs and people missing gas boilers, but Lowes thinks there will be an inevitable movement away from combustion in homes, not just for climate change reasons but because of concerns over indoor air pollution. “Longer term, the idea of burning stuff in the house will be seen as completely daft.” ❚
▲ Space cookies Astronauts will be baking cookies in a new space oven as a PR stunt. Looks as if it worked, given that we are writing about it. ▲ Pet face-swap Ever wish your dog was a lion? Obviously not: think of the furniture. But if you insist, NVIDIA has made a photo app that morphs the face of one animal into another. ▲ Vampire bats Creatures of the night are generally unfriendly, but it turns out vampire bats form close relationships in captivity and retain them in the wild. ▼ Climate meeting
For more on what we need to do to tackle climate change, see page 22
Greta Thunberg has had to beg a ride back across the Atlantic, as a major climate summit is moving from Chile to Spain.
“There is a tendency for people to think ‘I need solar panels or a whizzy app to control my heating’,” says Russell Smith at energyefficiency consultants Parity Projects. Try to resist the urge, he says. Instead, if you are looking at upgrading your existing home to cut carbon emissions, Smith recommends finding a local company to do an impartial energy assessment of your property to see all the possible opportunities. The priority should be to reduce the need for energy. A typical home uses 65 per cent of its energy for heating, so insulation is
Solar panels may not be the best way to cut your carbon emissions
key. “Insulating all external walls, floor and roofs, then upgrading windows and plugging all of the gaps to reduce draughts has a massive impact on bills and more so on comfort,” says Smith. Once it is airtight, you then need to keep an eye on ventilation to maintain air quality, though, he adds. Energy efficient appliances and lighting are next. Only once you have done everything you can to reduce demand should you look at a low carbon heat source – like a heat pump – or generating your own energy, such as through solar panels, says Smith.
▼ NHS pagers
REELDEAL IMAGES/ALAMY STOCK PHOTO; GETTY IMAGES
CHRIS HOWES/ALAMY
How to green your home
Pagers used by the UK’s National Health Service are leaking medical data over radio waves, possibly to the 1980s, where pagers belong.
9 November 2019 | New Scientist | 19
Home of tomorrow Radical plans are set to slash the carbon emissions of UK homes. Will people accept them, asks Adam Vaughan GAS boilers make for an unlikely UK election battleground, but politicians have been competing on who will phase them out the fastest. Last week, the opposition Labour party said it would make all new homes net-zero carbon from 2022, beating the Conservative government’s plans to rule out gas boilers from new homes by 2025. The Liberal Democrats in turn said they will make new homes net zero by 2021. Whoever wins next month’s election, the flicker of gas boilers is long due for extinction. The UK’s 26 million homes are responsible for about a fifth of the country’s carbon emissions, making the greening of them a key plank of slashing net emissions to zero by 2050 – now a legal requirement. Retrofitting those buildings will be a huge undertaking (see “How to green your home”, opposite).
running costs roughly equivalent to those of gas boilers. However, doing away with a gas connection means a financial saving both to society – because the cost of connecting the home to the pipe network is paid through everyone’s energy bills – and to the owner of the home, because they will no longer need to pay the gas standing charge that energy suppliers impose.
1
2
3 8 4
6 7
5
Homes that are net zero when it comes to carbon emissions will require many features that most current homes lack
New build Meanwhile, some 230,000 new homes are built in the UK every year, most of them reliant on fossil fuels for heating and hot water. That will radically change with the government’s recent future homes standard, which will apply to England from 2025, and could be followed by similar rules in Scotland, Wales and Northern Ireland. What will new homes then look like? Ministers hope the building regulations mean an average home’s carbon emissions will be 80 per cent lower in 2025 than one built to today’s standards. To reach that goal, the government isn’t explicitly banning gas boilers, but is implicitly ending them by proposing a reduction in home CO2 emissions that would be impossible to meet with one. Crucially, a home’s source of heat will have to be low carbon. 18 | New Scientist | 9 November 2019
1 Green roof
5 Ground source heat pump
2 Timber frame construction
6 Induction hob
3 Insulated walls and floors
7 Air source heat pump
4 Car charging point
8 Double glazing
For some, such as blocks of flats, it may come via a heat network, where a central boiler pipes hot water to every property. That is still likely to involve fossil fuels in the near term, but a central system is much more efficient than a block full of individual gas boilers. For many homes, the answer will be a heat pump – effectively a refrigerator in reverse – which uses a fan to extract heat from the
80%
How much lower the carbon emissions of new homes in England will have to be
ground, water or the air, even on a cold day. Most will be air source pumps, which involve a box like an air conditioning unit on the home’s exterior. Like a traditional boiler, these pumps can be used for hot water or space heating, so the inside of future homes won’t look much different. “It’ll have bigger radiators, running on lower temperatures, but otherwise it will look pretty much the same as a house today,” says Jenny Holland of the UK Green Building Council. There is a cost: heat pumps are about £3000 compared with about £1500 for a gas boiler, and they consume electricity, with
Changing behaviour Jenny Hill of the Committee on Climate Change, which advises the UK government, says the switch to heat pumps is likely to require some adaptation. “It does absolutely require behaviour change. We don’t currently know how people are going to react to not being able to install gas boilers in their homes.” For one thing, gas cooking hobs will be replaced by induction hobs, which are not only more efficient, but can now match gas for responsiveness when it comes to turning the heat up and down. “But they do require you to have COPY SUBis some a new set of pans, so there inconvenience there,” says Hill. PAGE SUB It isn’t just boilers: the fabric of future buildings willpress be OK for transformed (see diagram). Their walls, floors and roofs will have to be much better at retaining heat than today’s, and they will need high-performance windows. Homes will have to be airtight, but still well-ventilated. Richard Lowes at the University of Exeter, UK, says walls are likely to look the same, but have more efficient insulating materials inside them. With windows, double glazing is so good now in performance that triple glazing is unnecessary. Other potential changes include a growing use of timber frames for buildings, which
tomorrow house_091
Working hypothesis
More Insight online
Your guide to a rapidly changing world newscientist.com/insight
lock-in carbon, and “green roofs” covered in vegetation, providing a natural form of insulation to reduce energy consumption. Although 2025 is the key date, the government is proposing an interim strengthening of regulations next year. That won’t force the switch to greener heating, but promises a cut of 31 per cent on carbon emissions and more than £200 off average annual energy bills for new builds, versus rules today. Solar panels, already on the roofs of nearly a million homes, would be one way to do that, officials suggest. Hill says there is definitely a role for solar panels, but they are no substitute for a low-carbon heat source. “You have to look at how you decarbonise your heating and that is what delivers the bulk of your savings.” Home battery storage devices, which can store electricity from solar panels and exploit off-peak energy tariffs, are expected to be niche initially and are unlikely to be standard in new homes. “It comes down to the economics:
batteries are expensive. You don’t need solar power or a battery but it’s nice to have,” says Lowes. The Home Builders Federation trade body says it welcomes standards on carbon emissions, but argues that the government’s
“We don’t currently know how people are going to react to not being able to install gas boilers” proposals would be very challenging and require a lot of work on supply chains. Such concerns can have an impact. In 2015, the government shelved zero-carbon home standards a year before they took effect, in a sop to developers. Hill questions why the UK construction industry should find the rules a challenge, when a gas-reliant country such as the Netherlands has already introduced rules banning gas boilers without it causing problems. “From our perspective, we believe the technology exists now
Sorting the week’s supernovae from the absolute zeros
to build homes that are net-zero compliant, water efficient and don’t overheat. The problem we have is with the skills and industry.” Compliance regimes for new homes, enforced by thinly stretched local authorities, aren’t fit for purpose, she adds. Hill also believes that the new standards should be introduced before 2025. Still, the future homes rules have been broadly welcomed, even if they could be tightened up in places. “There’s a general thing here about moving away from fossil fuels, which is to be applauded,” says Lowes. There may be grumbles in some quarters about induction hobs and people missing gas boilers, but Lowes thinks there will be an inevitable movement away from combustion in homes, not just for climate change reasons but because of concerns over indoor air pollution. “Longer term, the idea of burning stuff in the house will be seen as completely daft.” ❚
▲ Space cookies Astronauts will be baking cookies in a new space oven as a PR stunt. Looks as if it worked, given that we are writing about it. ▲ Pet face-swap Ever wish your dog was a lion? Obviously not: think of the furniture. But if you insist, NVIDIA has made a photo app that morphs the face of one animal into another. ▲ Vampire bats Creatures of the night are generally unfriendly, but it turns out vampire bats form close relationships in captivity and retain them in the wild. ▼ Climate meeting
For more on what we need to do to tackle climate change, see page 22
Greta Thunberg has had to beg a ride back across the Atlantic, as a major climate summit is moving from Chile to Spain.
“There is a tendency for people to think ‘I need solar panels or a whizzy app to control my heating’,” says Russell Smith at energyefficiency consultants Parity Projects. Try to resist the urge, he says. Instead, if you are looking at upgrading your existing home to cut carbon emissions, Smith recommends finding a local company to do an impartial energy assessment of your property to see all the possible opportunities. The priority should be to reduce the need for energy. A typical home uses 65 per cent of its energy for heating, so insulation is
Solar panels may not be the best way to cut your carbon emissions
key. “Insulating all external walls, floor and roofs, then upgrading windows and plugging all of the gaps to reduce draughts has a massive impact on bills and more so on comfort,” says Smith. Once it is airtight, you then need to keep an eye on ventilation to maintain air quality, though, he adds. Energy efficient appliances and lighting are next. Only once you have done everything you can to reduce demand should you look at a low carbon heat source – like a heat pump – or generating your own energy, such as through solar panels, says Smith.
▼ NHS pagers
REELDEAL IMAGES/ALAMY STOCK PHOTO; GETTY IMAGES
CHRIS HOWES/ALAMY
How to green your home
Pagers used by the UK’s National Health Service are leaking medical data over radio waves, possibly to the 1980s, where pagers belong.
9 November 2019 | New Scientist | 19