MBIE’S amendments

//MBIE’S amendments

MBIE’S amendments

NZIBS Executive member in charge of technical matters, Ed Morris, breaks down major changes to New Zealand’s building laws to improve the quality of building work. The Ministry of Building, Innovation and Employment’s proposed amendments to the acceptable solutions and verification methods is an attempt to make the design of buildings and engineering requirements easier and faster at the design stage.

It is hoped that some of the engineering will no longer require verification methods or specific design to be used as they have been brought under the acceptable solutions and verification solutions.

Below are excerpts from MBIE on the proposed changes:

Proposed changes to B1
Structure

The advantages of this proposal to amend Verification Method B1/VM1 and Acceptable Solution B1/AS1 are that:

  • Current knowledge and practices would be reflected in the B1 Acceptable Solutions and Verification Methods
  • Non-specific design information will be provided for low-rise light steel framed buildings
  • Information on the design of house foundations on expansive soils will be retained in an Acceptable Solution after SH/AS1 is revoked
  • Maintaining and updating B1/AS1 will help consenting efficiency as certain designs on expansive soils or for light steel framed buildings will no longer need to be treated as alternative solution proposals
  • Changes reflect continued maintenance of the B1 Acceptable Solutions and Verification Methods to ensure the Building Code System operates efficiently.

Proposed changes to B2
Durability

The advantages of doing this are that:

  • Current knowledge and practices would be reflected in the Acceptable Solution
  • The Acceptable Solution would clearly specify requirements for corrosion protection for light steel framing
  • Maintaining the Acceptable Solution will help consenting efficiency as steel protection measures for light steel framing will no longer need to be treated as alternative solution proposal
  • Changes reflect continued maintenance of the B2 Acceptable Solutions and Verification Methods to ensure the Building Code System operates efficiently.

Proposed Changes to E2
External Moisture

The advantages of issuing the proposed new Verification Method E2/VM2 are that:

  • Current knowledge and practices would be reflected in the E2 Acceptable Solutions and Verification Methods
  • A means of demonstrating NZBC compliance for clause E2.3.2 External Moisture for certain buildings up to 25m in height is made available which does not rely on engaging an expert façade consultant. There is currently no Acceptable Solution or Verification Method for NZBC clause E2 for buildings taller than 10m in height
  • Manufacturers and suppliers of cladding systems who utilise the Verification Method will all demonstrate the same levels of performance, so any such cladding system may be used on any building within the scope of the Verification Method
  • Matters that affect the performance of cladding systems will become better known and understood amongst the sector as the Verification Method is adopted and suppliers publish technical information on their conforming cladding system
  • Providing this Verification Method will help consenting efficiency because weathertightness designs for certain buildings up to 25m in height will no longer need to be treated as alternative solution proposals
  • Changes reflect continued maintenance of the E2 Acceptable Solutions and Verification Methods to ensure the Building Code System operates efficiently.

Proposed changes to G4
Ventilation

The advantages of doing this are that:

  • Current knowledge and practices would be reflected in the Acceptable Solution
  • Ventilation methods that are outdated and not used are removed
  • Information in the Acceptable Solution is kept relevant with referral provided to other documents where necessary
  • Changes reflect continued maintenance of the Acceptable Solution to ensure the Building Code system operates efficiently.

Proposed changes to G12
Water supplies

Proposes to cite the latest version of AS/
NZS 3500 Parts 1 and 4 to:

Update requirements for pipe jointing

  • The jointing materials and methods have been updated to ensure they are complete and easily followed by plumbing practitioners.
  • Prohibit the exposure of plastic pipe to UV radiation

There was a lack of clear prescriptive provisions for installing plastic piping in direct sunlight and the consequent adverse effect of UV radiation. Updated provisions in the Standard provide clarity about the protection of different types of plastic pipe from direct sunlight.

  • Introduce improved requirements for forced circulation heated water supply systems

The new Part 4 includes a new section titled ‘Sizing and installation of circulatory heated water reticulation’ as well as three new Appendices dedicated to forced circulation heated water systems. The lack of information in the current version of the Standard has resulted in these heated water systems not being fit for purpose resulting in a reduced service life (with some failures experienced within 2 to 10 years in Australia) and hence non-compliance with the Building Code’s durability provisions. These types of larger scale heated water systems are generally found in apartment, commercial or institutional buildings; not in individual household units.

  • Allow thermostatically controlled tapware as an alternative to mixing valves

Thermostatically controlled taps have been added as they have been increasingly used in Australia as an alternative to mixing valves.

The advantages of doing this are that:

  • Current knowledge and practices would be reflected in the Acceptable Solutions and Verification Methods
  • Maintaining and updating the G12 Acceptable Solutions and Verification Methods will help consenting efficiency as improvements in pipe jointing, protection from UV radiation, and the use of thermostatically controlled tapware will no longer need to be treated as alternative solution proposals
  • Changes reflect continued maintenance of the G12 Acceptable Solutions and Verification Methods to ensure the Building Code System operates efficiently.

Proposed changes to G13
Foul Water

Proposes to cite the latest version of AS/
NZS 3500 Part 2 to:

  • Provide a solution for renovating sanitary plumbing and drainage systems

The main amendment within this Part relates to the installation of structural plastic liners for renovating sanitary plumbing and drainage systems. The previous version has a provision for this repair work but did not give a specific solution. A prescriptive solution is now provided that provides certainty about the minimum requirements necessary for this work.

  • Prohibit the exposure of plastic pipe to UV radiation

There was a lack of clear prescriptive provisions for installing plastic piping in direct sunlight and the consequent adverse effect of UV radiation. Updated provisions in the Standard provide clarity about the protection of different types of plastic pipe from direct sunlight.

The revised Part also incorporates a number of editorial changes and improvements for clarity.

The advantages of doing this are that:

  • Current knowledge and practices would be reflected in the G13 Acceptable Solutions and Verification Methods
  • Maintaining and updating the G13 Acceptable Solutions and Verification Methods will help consenting efficiency as a means of renovating sanitary plumbing and drainage systems and providing protection from UV radiation will no longer need to be treated as alternative solution proposals
  • Changes reflect continued maintenance of the G13 Acceptable Solution to ensure the Building Code system operates efficiently.

Conclusion

Overall it appears that MBIE are actively listening to the industry and making sound changes to the codes where it would it make it easier for the designer and engineers. In turn these proposed changes are reflecting the changing times of the building industry.

The biggest proposed change is to the facades under E2. This will allow the possibility of facades not requiring specific engineering up to 25m. To have a good grasp of the design requirements for facades of this height, one would have to have a very good understanding of the potential risks that will need to be fully considered. We may still find that it will be easier to get these types of facades being designed by engineers.

Changes to B1 are being made due to the knowledge that has been gain from the testing of the products and using specific engineered design methods that have been carried out over a long period of time which can now be readily relied upon therefore can now come under the heading of Acceptable Solutions and Verification Methods. This will be both a cost and time saving at the design stage.

G4, these improvements are aligning with the Healthy Homes Standards. This is ensuring that all dwellings will have further control of internal moisture which is now becoming a concern within our industry. This requirement should have come in many years ago and is long overdue G12 and G13 are being amended to reference the latest version under AS/NZS:3500

Part 1 to 4, which has gone through some upgrade to allow new technologies and due to failures that have been experienced in Australia.

What’s on the horizon?

The latest from the government is “Building System Legislative Reform Programme”; the proposed legislation is wanting the building sector to be more accountable for their own work and the responsibilities of property owners and tradespeople. This includes a number of proposed law changes to the Building Act and maybe the largest changes to the Act in recent times. Please be assured that MBIE hold our institute and our members in high regard and they want our members to provide feedback. MBIE’s link is below where you may wish to read their proposals. From there we would like you to email your feedback to the executive committee where we will correlate all feedback and on-forward on to MBIE for consultation. For more information, visit www.mbie.govt.nz/building-reform

2019-05-08T15:47:15+00:00