In our design and subsequent PHPP we had chosen materials that were either not widely available or were simply found to be too expensive. This was especially apparent when pricing the wall insulation. Again by using insulation with a matching (or improved) thermal conductivity Lambda value we still stayed within the crucial 15kWh/m²/a of allowed energy required to heat this home.

There has been a constant updating of our working PHPP as we entered in different products to see what their implications would be on the overall verification of the project.

The table below demonstrates the overall U-Values for the major building elements, the lower the better!

Figure 2: Building Regs Vs Passive House U-Values for this build

You will note the all-important Lambda value of 0.035 from the photo above.