The world needs to go carbon neutral by 2050, according to the major UN climate report released on Monday. To achieve that, countries need to 鈥渄eep retrofit鈥� old homes, says another report.
An incremental approach, such as insulating lofts or installing more efficient gas boilers, is not enough, says the report from the Institution of Engineering and Technology (IET). Instead, the aim should be to completely transform houses to make them 鈥渘et-zero鈥�.
That means insulating an entire house to a very high standard, and installing sustainable heating systems, solar panels and the like, in one fell swoop.
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In the Netherlands, , with another 15,000 in the pipeline. The approach is now being extended to other countries, including the UK, US, Canada, Germany and France.
27 million homes
In the UK, cities and the government should launch a pilot programme to retrofit 30,000 homes as soon as possible, and help set up a national centre of excellence to help develop more effective methods. The aim must be to retrofit all 27 million homes by 2050.
鈥淚f we are to meet the 2050 targets, then all housing in the UK must have zero carbon emissions from space and water heating, and space cooling,鈥� says Rick Hartwig of the IET.
But there are formidable obstacles. The greatest is cost. The city of Nottingham has already deep-retrofitted 10 properties, and the cost was around 拢80,000 per property, says Marjan Sarshar at Nottingham Trent University, one of the authors of the report.
This is too expensive, she says. But the costs would fall sharply if there was a massive programme of deep retrofitting, and vast quantities of the required components were being manufactured on a huge scale.
Additional benefits
There would also be a wide range of benefits beside reducing carbon emissions, say Richard Miller of Miller-Klein Associates, another author. In addition to cutting energy bills and increasing the value of properties, retrofitting would reduce air pollution, improve the health of people living in poor-quality homes and provide a huge boost to the local economies. Bad housing is estimated to cost the NHS 拢1.4 billion a year, Miller points out.
Another problem is some houses are much more difficult to retrofit than others. The basic idea is to 鈥渢hrow a duvet over a house鈥�. In Nottingham, this was done by adding thick cladding to the walls and replacing the roof.
But this approach alters the look of homes and is only suitable for around a third of the UK鈥檚 27 million houses. It鈥檚 not yet clear how the rest could be upgraded to the necessarily standard, but it might be possible by, for instance, installing thin insulation on interior walls.
In the meantime, we should focus on the houses that can be more easily retrofitted. 鈥淭here鈥檚 enough that鈥檚 doable that we should get on with it,鈥� Miller says.
No alternative
We don鈥檛 have an alternative, he says. Currently most houses in the UK are heated by natural gas. 鈥淕as cannot be part of the 2050 solution.鈥�
Nor is it feasible to replace gas with electricity from renewable sources. The peak energy demand in winter is six times higher than the total electricity demand, Miller says.
It remains to be seen whether the UK government will be persuaded. The current government has cut many environmental initiatives, including the 鈥淕reen Deal鈥� meant to finance home improvements such as installing insulation and a requirement for new homes to be carbon neutral.
Last month, the UK鈥檚 Climate Change Committee warned that the country was not doing nearly enough to meet its own targets. The chair of the committee particularly highlighted the failure to build new homes to the highest environmental standards.
鈥淢any new-build houses being put up will have to be retrofitted,鈥� Miller says.
