OT_044: BRANZ Bulletin 678 (2022) — H1 Calculation Method (Housing & Buildings ≤300 m²)

OT_044: BRANZ Bulletin 678 (2022) — H1 Calculation Method (Housing & Buildings ≤300 m²)

Source

https://www.branz.co.nz/pubs/bulletins/bu678/ — original source (opens in a new tab; the file is not redistributed)

Summary

BRANZ Bulletin 678 (2022) explains the calculation method for demonstrating compliance with the H1 5th edition Energy Efficiency requirements — the more flexible alternative to the schedule method (the fixed element R-values in OT_043). Rather than meeting every element’s R-value individually, the designer calculates the proposed building’s total heat loss and shows it is no greater than that of a notional reference building built to the schedule values, which allows trading off elements (e.g. more glazing offset by better-insulated walls/roof). For Neobiome Intelligence it documents the mechanism by which a high-performance community build proves it meets — or beats — the H1 baseline, complementing the R-value schedule in OT_043 and the above-code multipliers in CR_017.

Key claims

- claim: "Bulletin 678 sets out the H1 calculation method for housing and buildings up to 300 m² under H1/AS1 5th edition — an alternative compliance route to the schedule method. The previous NZS 4218:2009 calculation method no longer applies, and the climate zones have been modified to six zones (with staged window/door requirements for zones 1–2 vs 3–6)."
  source_location: "§1.0.1–1.0.4 (p.1)"
- claim: "Under the calculation method, the designer works out the total heat loss of the proposed building from the areas and construction R-values of all its elements, and compares it to a notional reference building built to the schedule-method R-values. If the proposed building's heat loss is less than or equal to the reference building's, it complies."
  source_location: "§2.0.1–2.0.3 (pp.1–2)"
- claim: "The calculation method offers flexibility: a designer can amend element R-values or the design (e.g. compensate larger glazing areas with higher insulation elsewhere) until the proposed building's calculated heat loss is at or below the reference building's — trade-offs not permitted under the rigid schedule method."
  source_location: "§2.0.3–2.0.4 (p.2)"

Neobiome Intelligence relevance

• ④c / D04 — compliance mechanism for above-baseline builds. The calculation method is how a Neobiome high-performance build demonstrates it meets or exceeds the H1 baseline (OT_043) while trading off elements (e.g. larger north glazing for passive solar gain, offset by a higher-R roof) — the practical route to the model’s high_performance / passive_house standards without being locked to per-element minimums OT_044. No new R-value or cost data — a methodology document; the values stay with OT_043 / CR_017.

Research targets

Research gaps

• A worked NZ heat-loss comparison (proposed vs reference building) at the pilot’s climate zone showing the element trade-offs and the resulting heat-demand delta — would connect the calculation method to the model’s ④c heat_demand_multiplier directly.

Connections

Links to

Sources (1): OT_043

Referenced by

Sources (4): OT_131 · OT_132 · OT_133 · OT_134

EDT domains (1): D04: Sustainable Habitat & Building Technology