Net zero could be curtains for sash windows
House builders demand code to allow them to fit replacement units without planning permission
SASH windows may start to disappear as proposed net zero regulations for landlords clash with conservation rules.
Landlords are obliged to meet minimum energy efficiency standards in properties and proposals under consideration would substantially raise requirements in the coming years.
The strategy, a key part of the Government’s net zero target, requires carbon emissions from domestic properties to be “largely eliminated” by 2050.
The best way to improve energy efficiency in a home and comply with the incoming rules is likely to be to upgrade its windows.
Landlords are exempt if they spend £3,500 towards this but fail to reach the energy efficiency target. This would rise to £10,000 under the proposed rules.
Owners of properties in conservation areas and listed buildings usually have to apply for consent to replace windows on a case-by-case basis, which is slow and expensive.
The National Federation of Builders (NFB) said the rules drive up costs and stifle the market for modern, doubleglazed sash windows, with some landlords simply giving up.
They have called for a new code that would allow the installation of new windows without planning permission.
Rico Wojtulewicz, head of housing and planning policy at NFB, said: “Historic England, heritage groups and the energy sector should come together and create an acceptable materials and product code so that you don’t have to go through the planning process to change the windows.”
Historic England, the body that makes recommendations on heritage planning, welcomed the suggestion.
It said sash windows were “invaluable in helping to cool buildings” and it wanted to see a stronger market for them.
Simplifying the planning system for heritage homes, which account for some two million properties, would stimulate the market and bring down costs, according to the NFB.
Mr Wojtulewicz said that the planning system forced owners to wait up to six months for planning permission while material and labour costs often soared.
In some cases owners had simply installed traditional, single-glazed windows at great expense but with no efficiency gains because of delays in obtaining planning permission.
“[The Government] needs to give the market certainty … by creating fair regulation, not overregulation,” added Mr Wojtulewicz. “You need to create a market.”
Wooden windows can be six times more expensive than uPVC versions, although they can last up to four times longer, so lifetime cost competitiveness may not be dissimilar.
Historic England said that a catch-all code was unlikely to be suitable, because of the wide variety of types and styles of sash window, “but there may be scope to explore codes for particular groups of buildings, for example in conservation areas of relatively uniform character, or, perhaps, groups of similar listed buildings”.
Traditional windows would be essential when adjusting to climate change, it said: “The critical ventilation provided by opening both upper and lower sashes is wonderfully cooling and we’d like to see more people using them in this way.”
Rented properties are required to reach a minimum EPC rating of E. Under the new proposals this would be raised to C by 2025, for new and renewed lets, and to 2028 for existing tenancies. Some lenders in the buy-tolet market offer discounted mortgages to landlords with more energy-efficient homes as the threat of properties becoming unlettable rises.
David Hitches, head of property risk at Paragon, a mortgage specialist, said that it was still early days but “in due course, we will see the differentiation in value becoming more evident”.
There are an estimated one to two million homes in conservation areas and 400,000 listed buildings in the UK, although the two figures overlap and not all of them will be from an era when sash windows were fitted.