Achieving a high performance thermal envelope at Passivhaus performance levels relies not only on good insulation levels but also avoiding heat loss through thermal bridges as well as any ventilation losses through gaps in the thermal envelope.
Thermal bridging and air gaps can potentially occur at any junction between the floor, wall and roof, as well as at openings.
We can calculate the psi value of these junctions using 2D heat flow software( Flixo) which can then be fed into the PHPP Calculations.The PHPP requires that all thermal bridges that are greater then 0.01W/(mK) are identified and calculated.
It also requires that an airtight envelope is achieved and that this air pressure tested on site.
