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*ARCHIVE* - BIA Update 42 - Implementation of Acceptable Solutions B2/AS1 and E2/AS1 2 Nov 2004

Acceptable Solution B2/AS1 implementation

In December 2003 the Building Industry Authority (BIA) announced amendments to its Acceptable Solution, B2/AS1, dealing with the use of treated and untreated timber. The amendments require higher levels of timber treatment in parts of buildings more at risk of decay caused by leaking.

The new Acceptable Solution applies to any application for a building consent received on or after 1 April 2004.

When the amendment to B2/AS1 was announced, the BIA put in place a transition period of one year for those building to the old Acceptable Solution to gain a code compliance certificate  (CCC). This transition period no longer applies.  

Under the Building Act 2004, from 31 March 2005 CCCs will be assessed against the conditions in the original building consent, rather than against the Building Code in place at the time of the assessment.

The Authority has therefore decided that the policy intent of the new Act should apply for those who are already building under the old Acceptable Solution. Their buildings will therefore be assessed against the conditions of the original building consent and hence the old Acceptable Solution.

It must be remembered that the old Acceptable Solution only allows kiln-dried untreated timber framing if its in-service moisture content remains below 18 percent. Weathertightness failures have demonstrated that this condition will not be achieved when there has been a lack of understanding of weathertightness principles, poor detailing, no flashings, poor construction practice and no drainage plane.  

In deciding whether a building is Code compliant, the Authority would expect an adequate inspection of the cladding and measurement of the moisture content of the framing in vulnerable locations. If untreated framing is being exposed during remedial work, the Authority recommends that territorial authorities (TAs) require surface treatment of the exposed framing to give additional protection against mould growth and decay. Additionally, it is recommended that owners are made aware of their obligations to maintain the cladding of their house.  

TAs have no statutory responsibility for the ongoing maintenance of a building. However, the owner could discuss an appropriate maintenance programme with the TA, bearing in mind that any comments or advice provided by the TA should be accompanied by appropriate disclaimers. 

Acceptable Solution E2/AS1 implementation

On 23 June 2004 the BIA announced a new Acceptable Solution, E2/AS1, for the way buildings are designed and built to help overcome leaky building problems. It contains much more detail and advice than before on how buildings should be designed and built to achieve weathertightness.

The implementation date for the revised E2/AS1 was originally given as 1 February 2005, subject to feedback from industry. Feedback received indicated that additional time before implementation is required to allow industry to test products and systems to make sure they fully comply with new requirements in E2/AS1. As a result, the implementation date for E2/AS1 has been put back to 1 July 2005.

For those applying for a building consent on or after this date, the changes will apply to their project. They are advised to talk to their builder or architect to make sure the new weathertightness practices have been considered before a building consent application is filed.

The changes to E2/AS1 will not affect those who have a building consent complying with the current E2/AS1 (second edition, amendment 5, dated 9 February 2004). The Authority has decided that the policy intent of the Building Act 2004 should apply for those who are already building under the old Acceptable Solution. Their buildings will therefore be assessed against the conditions of the original building consent and hence the old Acceptable Solution.

The B2 and E2 Approved Documents that contain B2/AS1 and E2/AS1, respectively, are available for purchase from the Victoria University Book Centre (phone 0800 370 370 or visit www.vicbooks.co.nz). 

Trained and approved applicators in E2/AS1

Industry feedback on the implementation date for E2/AS1 also indicated that the introduction of trained and approved installers for cladding systems was going to be difficult to achieve in the available time.  

The new Building Act sets out a process and timeline for the introduction of Licensed Building Practitioners. As a consequence, the Authority has decided to delay implementation of the new requirements for installers in E2/AS1 until the scope and requirements for licensing are developed. As a consequence the following paragraphs will not be implemented on 1 July 2005. 

  • 1.5 general requirement for the approval of applicators. 
  • 8.2.2 requiring masonry roof tiles to be installed by tilers approved by the manufacturer or the NZ agent. 
  • 8.3.2 requiring pressed metal tile roofing to be installed by trained installers approved by the manufacturer or NZ agent. 
  • 8.4.2 requiring the profiled metal roof cladding installers to be approved by the manufacturer or NZ agent. 
  • 8.5.2 requiring membrane roof cladding installers to be approved by the manufacturer or NZ agent. 
  • 9.2.2 requiring masonry veneer installers to be approved by the manufacturer or NZ agent. 
  • 9.3.4 requiring slid plaster/stucco to be applied by experienced applicators. 
  • 9.6.2 requiring profiled metal wall cladding installers to be approved by the manufacturer or NZ agent. 
  • 9.7.10.2 requiring flush-finished fibre-cement installers to be approved by the supplier of the jointing and finish system.