Building envelope

Weathertightness & moisture control

• 🇳🇿BRANZ Weathertightness OverviewBRANZA BRANZ overview of its FRST-funded weathertightness research — the building science behind moisture management in walls that informed Building Code Acceptable Solution E2/AS1 and reducing "leaky building" failures.
• 🇳🇿Code of Practice for Internal Wet-area Membrane SystemsMinistry of Business, Innovation & Employment (MBIE) · 2020The Waterproofing Membrane Association's code of practice for internal wet-area (e.g. bathroom) membrane systems — selecting, designing and installing waterproofing to meet Building Code clause E3 internal moisture.
• 🇳🇿Constructing Cavities for Wall CladdingsMinistry of Business, Innovation & Employment (MBIE) · 2004MBIE guidance (read with E2/AS1) on constructing drained cavities behind wall claddings — wall underlays, cavity battens, drainage and ventilation, and junctions at windows and doors.
• 🇳🇿Drained and Vented Cavities (BRANZ Bulletin BM83)BRANZ · APRIL 2017A BRANZ bulletin on weathertight flashing and drained/vented cavity detailing — how correct cross-falls and flashing design drain rainwater from junctions between walls, roofs and windows.
• 🇳🇿Excessive Moisture in Enclosed Subfloor Spaces (BRANZ Bulletin 594)BRANZ · February 2016A BRANZ bulletin on excessive moisture in enclosed subfloor spaces under suspended timber floors — the causes and effects, and how to avoid, detect and remedy high subfloor moisture through ventilation and ground cover.
• 🇳🇿External and Internal Membranes — Guidance (AC2234)Auckland Council · May 2019An Auckland Council practice note on external and internal waterproofing membranes — addressing common deck, roof and gutter membrane failures and the design and detailing needed to pass building-consent checks.
• 🇳🇿External Envelope Guidance (AC1827)Auckland Council · June 2022Auckland Council building-consent guidance for applying for a new external envelope on buildings over 10 m tall — design-phase expectations and documentation for weathertight, durable façades.
• 🇳🇿External Moisture — An Introduction to Weathertightness Design PrinciplesMinistry of Business, Innovation & Employment (MBIE) · 2004MBIE's introduction to weathertightness design principles (read with E2/AS1) — the fundamentals of keeping external moisture out of buildings through sound envelope design.
• 🇳🇿Healthy Homes Standards — Moisture Ingress and DrainageTenancy Services (MBIE) · July 2025A Tenancy Services (MBIE) guide to the Healthy Homes moisture-ingress and drainage standard for rental properties — the drainage, guttering and ground-moisture requirements landlords must meet.
• 🇳🇿Internal Gutter Design (BRANZ Bulletin 556)BRANZ · February 2013A BRANZ bulletin on internal (box) gutter design — the E1/AS1 and E2/AS1 requirements and design parameters for sizing internal gutters and minimising the risk of water entry.
• 🇳🇿Vapour (BRANZ Bulletin 604)BRANZ · December 2016A BRANZ bulletin on vapour and condensation control in New Zealand buildings — how moisture moves through construction, the role of dew point and humidity, and options for reducing condensation risk in walls.
• 🇳🇿Waterproof Decks (BRANZ Bulletin 583)BRANZ · April 2015A BRANZ bulletin on waterproof decks over habitable spaces — the E2/AS1 requirements, alternative options and the design and construction risks for these low-slope roof decks used as outdoor living areas.
• 🇳🇿Weathertightness — Guide to Remediation DesignMinistry of Business, Innovation & Employment (MBIE) · May 2011MBIE/BRANZ guidance on the remediation design of weathertightness ("leaky building") failures — how to design durable, code-compliant repairs to the building envelope.
• 🇳🇿Weathertightness — Guide to the Diagnosis of Leaky BuildingsMinistry of Business, Innovation & Employment (MBIE) · 2004MBIE guidance on diagnosing weathertightness failures in leaky buildings — the assessment process from pre-site work and visual investigation to moisture detection and identifying water-ingress paths.
• 🇳🇿Weathertightness Design Requirements for New School BuildingsMinistry of Education · September 2020Ministry of Education weathertightness design requirements for new school buildings — mandatory design rules and prohibited materials and features for architects and designers of school property.