Building Physics comparisons
Modelling, calculation and assessment methods that predict how a building really performs.
Building physics assessmentPHPP vs SAP / RdSAP Energy Modelling
PHPP is a design tool that predicts real energy performance accurately; SAP and RdSAP are compliance and EPC tools, simplified for consistency rather than precision. For Building Regulations and an EPC you need SAP/RdSAP; to design a building that genuinely performs, you use PHPP.
Read comparisonPHPP vs EPC
PHPP is a design-accurate energy model; an EPC is a simplified rating. PHPP predicts real performance closely because it models thermal bridges, ventilation and site climate in detail; an EPC uses RdSAP defaults for consistency across millions of homes and is not intended as a design prediction. For an EPC you need RdSAP; to design a building that genuinely performs, you use PHPP. Treating the EPC band as a design target is a recipe for the performance gap.
Read comparisonBuilding Physics Assessment vs a Standard Survey
A standard survey inspects condition; a building physics assessment predicts performance. The survey records what can be seen — cracks, damp staining, the state of finishes — which is exactly what a buyer needs. A building physics assessment goes further, using modelling to calculate heat loss, thermal bridges and condensation risk and to predict how a building (or a proposed fix) will perform. Most contractors recommend work from visible symptoms; the assessment predicts outcomes before anything is built.
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