• markmcphee

Summer overheating – Do you know that Passivhaus design can help?

It is no understatement to say that it is hot outside, as I am sat writing this blog post the weather forecast today for Exeter is for the outside temperature to reach 32°C. However, we are not just sweltering outside, the inside of the majority of our buildings are struggling to cope with the heat. The good news is that the Passivhaus (PH) building modelling software (PHPP) allows us to test designs for summer overheating. So, if you are undertaking a house remodelling or having a new house designed there should be no need to get so hot and sticky!


Modern houses are particularly susceptible to overheating in the summer. As houses have become more heavily insulated with increasingly larger areas of glazing, the sun heats the internal surfaces of the rooms so that internal room temperatures rise beyond what would be considered comfortable. As weather patterns change with more hot spells, summer overheating is only going to become a greater risk.


Whilst Passivhaus is known as a low energy design standard, it deserves to be better known for its comfort requirements, limiting summer overheating is integral to the standard. A building can’t pass certification if internal temperatures rise above 25°C for more than 10% of the year, although it is worth noting that most PH designers would try and keep it below 5%. The PHPP software also provides quantifiable data on the potential for overheating, which will allow the designer to test the design and make modifications accordingly.


If you’re planning some work to your home, I would highly recommend that you discuss with your architect the potential risk of overheating. The tools are out there to make sure that your new extension or home doesn’t need to be a compromise on your happiness or rely on air conditioning! As important as considerations such as sustainability and aesthetics are, a good home needs to be comfortable.

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