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Build & Sustainability

Taking the heat out of home worries – Tim Lambert; Spa Architects

There has been a lot of hype recently about what exactly the new building regulations – which came into effect earlier this year – mean for the glass in our homes, writes Tim Lambert, associate at Stokesley-based Spa Architects.

More specifically, the talk has been around what kind of impact there will be on windows and conservatories.

Do the new rules sound the death knell for our bright and airy (in a good, not draughty, way!) homes, leaving us doomed to wander around in endless gloom?

The Department for Levelling Up, Housing and Communities states the changes “mark an important step on our journey towards a cleaner, greener built environment, and it supports us in our target to reduce the UK’s carbon emissions to net-zero by 2050.”

The regulations are part of the roadmap to the Government’s Future Homes Standard and Future Buildings Standard – planned for 2025 – for which a key part is that all new builds are capable of being net-zero in terms of operational carbon when the grid decarbonises.

The new Approved Document O introduces glazing limits in new build homes, care homes, schools and student accommodation to reduce unwanted solar gain. It also stipulates new levels of cross-ventilation.

At the worrying end, there have been siren calls the measures which limit glass size to a smaller percentage of a home’s coveted square meterage are akin to a new window tax.

The progressive window tax was a late 17th century invention applied to every window in the land to raise revenues for the Exchequer, which was in trouble because of illegal ‘clipping’ or theft of the metal used to make coins.

The tax meant everyone, except the most well off, were forced to remove many but the most essential of their windows.


Tim Lambert, associate at Stokesley-based Spa Architects

I’d like to reassure readers the building regulations do not mean anyone will have to forcibly remove existing windows or dismantle the conservatory; heaven forbid. You’ll still also be able to commission that new conservatory or orangery you’ve been dreaming of.

Firstly, the regulations apply only to new build houses and flats/apartments with more stringent controls on developments in areas of high risk (of overheating) dense urban areas; so, at present, only Central London and seven postcodes in Manchester.

The size of windows on the hotter south or west sides/elevation of the buildings will be affected.

Crucially, the rules will only apply to new developments in England, as the devolved nations have their own stipulations.

The regulations undoubtedly mean in the future, windows on new build homes may become smaller, require solar shading as many homes do in southern Europe, or may even be absent on the problematic elevations of the new builds.

It is our duty as designers to provide creative solutions that retain high levels of natural light in the building and make the most of all-important views while achieving (or surpassing) the requirements of the new regulations.

The real difficulty comes with apartments, as they are most often lacking in sides or elevations, so the developer would need to factor in the cost of accommodating the new requirements. The cost of more complex mechanical or purge ventilation (consisting of fans or air vents) will need to be factored in. This will mean that apartments in future are likely to become more expensive.

As it stands, the new regulations do not mean that English homeowners will be forced to dismantle their prized conservatories or brick up windows.

New homes, and certainly any home built from this year onwards will be extremely insulated to meet current regulations, and therefore prone to overheating.

Add hotter summers and densely packed housing into the mix and you have a problem.

Houses with lots of glass get hotter, and many homeowners are, for instance, turning their backs on the sleek and contemporary bi-fold doors due to this issue.

Insulation is good, but lots of it, coupled with lots of glass, is not going to be that great for anyone living, and overheating, in such a space.

The nuts and bolts of the new rules and regulations can be found here: