30 January 2019 Wellington. Scoop: Overheating in your new home – yes you should check

High performance homes are designed to use the least amount of energy possible to keep the occupants comfortable and healthy. We carefully select the windows their shading and details of how they are installed down to the specific coatings on the glass. This produces homes that use almost no heating but in the summer time do not overheat excessively.

Unfortunately, there are more than a few cases where folks have thought they were building a high performance home, a ‘passive house like’ home, but have actually built a solar oven. When they complained they found out that there actually was no performance model, “There was no thermal engineering at all!” said one homeowner. Although there beautiful, architectural and modern home was (luckily) warm in the winter it was so hot they were considering moving out in the summer. (The inside of the upstairs ceiling was measured at 50°C!)

Imagine you beautiful new home. You love how it looks, well at first you do, but then it is so hot in the summer you can’t stand it. The only option your builder offers it to install a huge air conditioning system which involves cutting big holes in your house and putting a big noisy box outside next to your neighbors bedroom window. You know it’ll cost heaps to install and then more money to run it – but you can’t live when it’s this hot inside.

As a building uses less energy to stay warm it takes a smaller mistake with windows or shading to make your home horribly hot. Luckily if you carefully consider shading during the design you can have a home that stays warm almost for free and stays nice and cool in the summer as well. The thick insulation can work like a chilly bin and help keep you home warm but not if you don’t put in the right shading and windows.

My advice is to check, right up front, that your architect or designer has had a performance model done and can tell you (with NUMBERS) how much or little your home will overheat as part of the design. If you do not ask they most likely will not have this done. Yes you should check!