New Scientist - 09.11.2019

9 November 2019 | New Scientist | 19

“There is a tendency for people

to think ‘I need solar panels or a

whizzy app to control my heating’,”

says Russell Smith at energy-

efficiency 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

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.

How to green your home

Solar panels may not be

the best way to cut your

carbon emissions

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.” ❚

For more on what we need to do to

tackle climate change, see page 22

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

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

CHRIS HOWES/ALAMY REELDEAL IMAGES/ALAMY STOCK PHOTO; GETTY IMAGES

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:

▲ 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

Greta Thunberg has had

to beg a ride back across

the Atlantic, as a major

climate summit is moving

from Chile to Spain.

▼ NHS pagers

Pagers used by the UK’s

National Health Service

are leaking medical data

over radio waves, possibly

to the 1980s, where

pagers belong.

Working

hypothesis

Sorting the week’s

supernovae from

the absolute zeros

More Insight online

Your guide to a rapidly changing world

newscientist.com/insight

“We don’t currently know

how people are going to

react to not being able

to install gas boilers”