H1, E3, G4 and G5 compliance
in one commission
A complete building code compliance package for residential and small commercial projects — energy modelling, hygrothermal analysis, ventilation strategy, and consent-ready reporting delivered together, by one team.
H1, E3, G4 and G5 aren't independent — and treating them separately costs more and delivers less
Each clause addresses a different building performance requirement. But the inputs are shared: the same envelope specification, the same climate data, the same mechanical systems, the same construction details feed all four. When compliance modelling is split across separate consultants or done in isolation, inconsistencies accumulate — different assumptions, different climate files, different R-values. By the time the reports reach the consenting authority, they're rarely telling the same story about the same building.
H1 and E3 share the same envelope inputs
The wall build-up that determines your H1 R-value also determines the temperature and vapour profiles that drive E3 condensation risk. Optimising one without the other produces an envelope that may pass both individually but performs worse than a coordinated design.
Ventilation affects energy demand and moisture simultaneously
The MVHR or natural ventilation strategy chosen for G4 compliance directly affects the H1 energy demand calculation and the internal moisture loads that drive E3 risk. These decisions compound — get them in the same model, made at the same time.
Thermal bridges affect all four clauses
A junction detail that creates a thermal bridge affects heat loss (H1), surface temperature and condensation risk (E3), thermal comfort (G4), and can create moisture pathways. One calculation, four compliance implications — worth doing once, correctly.
One commission, consistent inputs across all clauses
Piecemeal compliance work tends to be scoped to the minimum required for each clause in isolation. A single integrated commission means consistent envelope assumptions, climate data, and construction details feeding all four reports — and a single point of contact for the design team.
Four clauses — one integrated scope
Each compliance element is fully covered within the package. Where individual services are available separately, links are provided — but the package delivers all four together with consistent inputs and coordinated reporting.
- H1/VM1 whole-building energy simulation
- Envelope trade-off optimisation — insulation, glazing, orientation
- Solar gain and overheating assessment
- Heating and cooling load calculations for system sizing
- Consent-ready H1 compliance report
- WUFI Pro hygrothermal simulation of priority assemblies
- Surface temperature factor (fRsi) and mould risk assessment
- Glaser steady-state interstitial condensation check
- Vapour control strategy recommendations
- E3 compliance documentation
- G4 ventilation compliance — natural, mechanical, or MVHR
- Room-by-room airflow distribution and fresh air rates
- G5 thermal comfort assessment — overheating and cold zone identification
- MVHR duct routing strategy and airflow assumptions for PHPP/VM1
- G4/G5 compliance documentation
Design optimisation within the package scope
The compliance package isn't just reports — it includes the design advice that makes the reports achievable without unnecessary cost or over-specification.
- Junction detail review and thermal bridge identification
- Design guidance for bridge minimisation
- Psi-value calculations available as an add-on
- Standalone thermal bridge service →
- Insulation specification — thickness, lambda, environmental impact
- Glazing ratio and orientation analysis
- Shading and overhang design guidance
- Solar gain optimisation for winter gain and summer protection
- H1/VM1 energy model with full documented inputs and outputs
- H1 compliance report — consent-ready format
- WUFI hygrothermal simulation files and moisture risk assessment
- E3 compliance documentation
- G4/G5 ventilation and thermal comfort assessment report
- Thermal bridge review summary and design recommendations
- Review call with your design team to walk through all findings
- One round of revisions following design team feedback