Thanks to a flexible and forward thinking local building control office who have given us approval to replace their SAP calculations for our PHPP file as they recognise the PHPP file far in exceeds current building regulations - a truly future proof design.

For example, current building control regulations require a minimum airtightness level of 10 air changes per hour (ACH). Passive House has a strict value of 0.6ACH, 16 times better than the current regulations. As the regulations play catch-up, we strongly believe that the extra capital outlay invested in a Passive House will out play the long term energy invested in a building. We are estimating that the Passive House approach will increase build costs by 8-10%

Crucially, the Passive House method will offer the inhabitants of the building a constant comfortable internal temperature and a much superior air quality for its inhabitants. This is coupled with the peace of mind that rising fuel costs will have little impact on their pockets.

Assuming energy costs will rise every year, initial calculations would suggest that there will be a "pay-back" on the Passive house construction method in year 10, "making money" thereafter!