TuffX’s Paul Higgins explains what the new Part O of the Building Regulations means for glass and glazing in new homes
The new Building Regulations Approved Document Part O is designed to tackle overheating in new residential buildings. As the first regulation of its kind in England, self-builders and housebuilders need to be clear about what is and isn’t affected when it comes to choosing glazing for their projects.
In a nutshell, Part O seeks to ensure that the design and construction of new residential buildings limit unwanted solar gain in summer and provide adequate means to remove heat from the indoor environment.
The Part O regulations are designed to protect people’s health and welfare by reducing the occurrences of high indoor temperatures in the face of rising global temperatures and the frequency of extreme events such as heatwaves. Along with the rest of the new Building Regulations, Part O came into force in June, and shortly after our UK summer arrived with temperatures reaching 40°C, cementing the urgent and necessary need for this.
We are now in the one-year transition period after the new Building Regulations came into effect, to allow for planning applications that are already underway. Any schemes where full plans or a building notice was submitted ahead of 15 June 2022 can be built to previous regulations if work starts within 12 months.
ROUTES TO COMPLIANCE
There are two routes to Part O compliance: first, the Simplified Method and secondly, Dynamic Thermal Modelling. For single dwellings such as new homes, the Simplified Method is most likely to be used, with the Dynamic Thermal Method more likely to be used for a block of flats, single aspect dwellings or buildings with more complex design requirements.
For the Simplified Method, Part O sets out tables detailing maximum permitted glazed areas, taking into consideration the location of the building and whether it has cross ventilation. Buildings in high risk areas – currently specific postcodes in central London and Manchester – may also need to provide shading for glazed areas at certain points (and the means for achieving this, such as external shutters and overhangs, are detailed in the approved document).
SOLAR SOLUTIONS
High-quality solar glass products will play an important part in achieving these new standards that self-builders, along with housebuilders and developers, must adhere to. By using a tinted coating on the exterior of the glass to reflect heat away from the interior, solar glass allows an ambient interior temperature to be achieved, reducing the need for expensive air conditioning, for example, which will also cut energy costs – something that is on everyone’s minds right now.
It is possible to fit solar glass that reflects twice as much heat as standard glass. For example, with the Approved Document Part O in mind, there are now specifically developed rooflights that achieve this through a coating, which unlike most solar glass is untinted, so it achieves maximum light transmission too.
While ensuring your rooflights and windows meet the new regulations, it’s important to also make sure they meet – and ideally exceed – the high standard of quality a homeowner expects: including maximising light transmission, being easy to maintain and looking exceptional. And of course, come winter, energy efficiency will be imperative, so make sure your glass products achieve the best low U-values too.
Paul Higgins is commercial director at TuffX