Improving fabric performance
Enhabit’s Design Brief service was used to improve the energy performance of a newbuild project to build a family home on the south coast, with views across Hayling Island and out to the English Channel. The client came to Enhabit with an advanced design, and a wish to go greener.
The client used our Design Brief service and we worked in conjunction with Helyer Davies Architects to identify options to improve fabric performance, reduce the risk of overheating and increase the efficiency of the building services. The result is a building with a space heating demand of 36 kWh/m2.annum, which is better than the AECB Building Standard, and a far reduced overheating risk, which should lead to lower energy bills and a more comfortable home.
“Your help and advice has been invaluable and much appreciated. I felt I was a lone voice in the project until you came along, and now I feel much more confident in what we are doing.” – Mike Nicholls, client.
Minimising overheating risk
Views are a high priority in such a beautiful location, and as such, the south facing glazing has been maximised on the property. Enhabit used the Passivhaus Planning Package (PHPP) to model the impact of different shading and glazing options on the frequency of overheating in the whole building. PHPP cannot model overheating on a room-by-room basis, but it is still a good tool to analyse overheating risk, so long as the assumptions and limitations are well understood. Deep reveals (up to 750mm) were introduced around south facing windows, as well as architectural overhangs. This combined with solar control glazing and internal blinds reduced the overheating risk to within the ‘Excellent’ Passivhaus category.
External blinds are far more effective than internal blinds at reducing the solar gains in homes, however in such an exposed coastal location, they would have to be very robust. Similarly, solar control glazing should be a very last option, since this will reduce solar heat gains in the winter as well as the summer, but with views as good as this, it is understandable!