PassivHaus is an entirely voluntary building performance standard that anyone setting out to build a low-energy home might be interested in. It’s gaining lots of attention in the UK and is based around the principle of reducing heating demand to a very low level rather than relying on renewables. The standards far exceed those of the current Building Regulations, and it is popular because there are many different ways to meet the criteria, with designers using a software package to predict the home’s future energy demand.

The house must be designed from the ground up as a PassivHaus. There is a complex spreadsheet known as the PassivHaus Planning Package (PHPP) into which you feed all the relevant construction details: the insulation depths, the window sizes and orientations, the junction details, etc. This gives you a predicted space heating demand (expressed in kWh/m2/yr). You keep adjusting the design until your outcome meets the standard. PassivHaus can be built using almost any construction method. However, there are some universal features: massive insulation (average depth 300mm), triple glazing with insulated frames, fantastic air permeability levels (must score better than 0.6 m3/m2/hr at 50pa), mechanical ventilation with heat recovery, etc.

The SIG360 Technical Centre can offer guidance on applying PassvHaus but recommend the use of a specialist consultant if you have an ambition to have the development formerly registered as a PassivHaus.

For further guidance, please contact us.