Weathertightness design requirements for new school buildings

We have updated the weathertightness requirements that must be met when designing the external envelopes of new school buildings.

About weathertightness design requirements

The weathertightness design requirements apply to all new state school buildings, including:

  • extensions and additions that increase the building footprint
  • projects that involve end-of-life replacement or the alteration of roof or wall cladding envelopes of existing buildings.

While the document is primarily aimed at architects and designers, it is also important for those who lead and coordinate school design work, such as project managers, school boards and Ministry property personnel.

In some areas our requirements exceed those of the New Zealand Building Code and Acceptable Solution details. These areas include increased roof slopes, additional drained and ventilated wall cavity requirements and increased cladding durability.

The weathertightness design requirements specify the required attributes for systems and materials that make up the external envelopes of new buildings. They also prohibit the use of certain material types and installations where these have been found from experience to not fully satisfy our performance expectations.

Make sure you are using the latest version of this document by directly downloading the document from the link below.

Our design review process

To ensure your design meets Ministry requirements, all new designs and those altering a building envelope or altering envelope materials must be checked by an independent and suitably qualified building envelope specialist.

Projects would typically include new buildings, remediation works, additions or alterations. Your project will need to follow one of the 2 design review processes:

  • school-led projects under $3m
  • all capital works projects and school-led projects over $3m.

School-led projects under $3m

The Ministry will pay for these reviews to be undertaken by its contracted Building Envelope Assessment Team once the project and budget has been approved. You need to allow $2,000 of your project capital budget to pay for this review. The invoice will be processed directly by the Ministry.

Please read through the submission requirements and review process below before submitting design documentation sets for a project.

Submission checklist

Plans and drawings will be assessed against the Ministry’s weathertightness design requirements and the building code.

Project managers or designers are required to submit project documentation for review to:

  1. General details including:
    • school name
    • school address
    • school ID
    • project name and a detailed description of works
    • Ministry project ID number
    • design company name
    • name of Ministry property advisor
    • Confirmation that the project budget has been approved in K2, and that the project has $2,000 of capital funding available to fund this review.
  2. Sufficient specification, construction detailing and referencing of manufacturer’s technical literature to provide contractors with clear and adequate guidance on construction requirements for code compliant construction.
  3. General arrangement drawings including site and building location, floor plans, elevations and roof plan with the scope of works identified.
  4. Cross sections through the building envelope.
  5. For the proposed works, large scale details for all flashings, junctions, changes of plane and assembly details at 1:10, 1:5, or 1:2 scale as appropriate, and clearly cross referenced to the general arrangement drawings.
  6. 3D views of complex flashing junctions. 
  7. Flashing details of any services penetrations through the external envelope. 
  8. Project-specific specification including proprietary products. 
  9. Risk matrix for E2 AS1  for all relevant roof elevations.

If you are submitting this information via a Dropbox link or similar, please make sure it contains only the requested information above.

Assessment and feedback

  • The Building Envelope Assessment Team will assess the plans and report back to the project manager/designer.
  • Any areas of concern will be listed and highlighted on the drawings. If any major concerns are identified, the appropriate infrastructure manager will be notified.
  • Solutions to the concerns raised will need to be worked out between the designer, project manager and overseen by the school's property advisor and infrastructure manager.

Amend highlighted concerns

  • There will not be a resubmission process.
  • It is expected that any feedback or changes noted on the report will be taken into consideration and modifications to designs made as required.

All capital works projects and school-led projects over $3m

This category includes all projects that create new building footprint or alter the external envelopes of existing buildings.

The project manager is responsible for organising a weathertightness review from an independent and qualified professional supplier at the cost of the project.

A project may be subject to a site audit prior to being completed. If so, this will check that concerns have been addressed. 

Weathertightness remediation projects 

Buildings built or modified from 1994 onwards are covered separately by the Ministry’s weathertightness remediation programme, which will address any occurrences of weathertightness failure on a case by case basis.

Projects to remediate buildings within the programme are reviewed by the Ministry’s weathertightness review panel. See our remediation process page for more information.

Weathertightness remediation process

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