In December 2008, we wrote: 'Christmas is almost upon us once again, and the time since the last one seems shorter as each year passes. 2008 has seen quite an economic change in the last half of the year. While we know the economy and the building industry is cyclical, picking when the down cycle will begin and planning for it is difficult. What it does mean is that 2009 will be a difficult year for the building industry to maintain workloads and income and to retain experienced staff.'
And so it turned out to be. Dwelling consents dropped to their lowest level in decades, with the total value of building work – commercial and residential – at a historical low. Some recent figures have suggested that the outlook is starting to look brighter for the residential construction market, but while the percentage increase is positive, it is based on a very low starting point. We can only hope that the small amount of growth will be maintained at a sustainable pace, but 2010 will still be a difficult year for the building industry to maintain workloads and income and to retain experienced staff.
Parting words from Eddie Bruce (the voice of the BRANZ Helpline)
I have been invited to make a contribution to the last edition of Guideline for 2009 since (as we used to say in the Army) I will be posted to the 'retired list' on 18 December 2009. Having given the invitation some thought, I decided that the thing that I most wanted to do was to acknowledge the contribution made by a large number of individuals around New Zealand that have used our helpline service and in the process have provided us with some very useful feedback from the 'coal face'. While we work hard to provide a competent service, not all of our ideas are original, and the feedback that we get from callers is an invaluable source of information to us. The major benefit to industry is that we are able to recycle it through the numerous publications that our Information Services team produces each year.
BRANZ has become an exciting place to work in recent times, with a new CEO (who is from the tools himself), backed and directed by a Board that really does understand the building industry and its needs. I have been privileged to have been part of this great organisation that is re-establishing its relevancy to the building industry at all levels. I am confident that this new direction will only enhance the services that BRANZ can offer the building industry of New Zealand.
Maintenance
Maintenance of buildings is a fact of life – it can't be avoided. We can design to minimise but not to eliminate. One of the key issues that need to be addressed by the design and construction industry is making sure that building owners are informed of the maintenance requirements for their buildings, particularly domestic buildings. A comprehensive booklet is provided with a new car or microwave purchase, but typically little or nothing is provided with a new house.
The reasons for raising this are the anecdotal reports of building failure where a significant contributory factor for the lack of performance is a lack of maintenance. A common issue is the owners not being aware of or ignoring the repainting requirements for the cladding installed on their property. Even a simple task like an owner not addressing a blocked downpipe and the gutters overflowing into the soffit can, if left unattended to, cause significant water damage to the building components such as wall framing, floor framing, and flooring and internal linings.
Wet area membranes
Designers need to identify the specific membrane by product name that is to be used to waterproof wet areas (saying selected membrane isn't specific enough) in the consent documents and the installer needs to install what is specified. There have been a number of cases recently where a BCA has refused to sign off waterproofing work because the membrane used was not the one specified. If a change is to be made then it needs to be submitted to the BCA as an amendment to the consent and be approved before the work is done. The change also needs to be approved by the designer or, if no designer is involved, be authorised as a variation to the contract by the owner (or owner's agent).
Area:perimeter ratio = simple maths
To work out the area to perimeter ratio for slab floors when working out the slab R-value, divide the total area of the floor by the length of the perimeter. (For example, for a 10 m x 10 m square building, this is 100 m2 divided by 40 = 2.5.) To get the slab R-value, use the BRANZ House Insulation Guide pages 89, 90 or 91, depending on the slab construction.
Sliding and bi-fold doors
Sliding and bi-fold doors are not included in E2/AS1, but the installation must still comply with the requirements of clause E2. Guidance on detailing for cavity and direct-fixed installations can be found in BRANZ Weathertight Solutions Volumes 1, 2, and 3. However, the BRANZ details do not incorporate a window support bar used in conjunction with a sill tray flashing for these windows, and manufacturers should be consulted for their specific installation details.
View BRANZ Weathertight Solutions Volumes 1 to 6. (http://www.branz.co.nz/cms_display.php?sn=70&st=1&pg=1220)
Alternative solutions using BRANZ Appraisals to support compliance
If using a BRANZ Appraisal to support a consent application as an Alternative Solution, the use of the material or system covered by the Appraisal must be within the scope of that Appraisal. Otherwise, it is not a valid use of the Appraisal.
LCA analysis tool
A life cycle analysis tool for claddings is available on the BRANZ website. (http://www.branz.co.nz/wall_claddings_tool)
H1 compliance
When submitting a consent application, there are a number of ways that H1 compliance can be demonstrated. To help choose the most appropriate method, use the flow charts in NZS 4218 or NZS 4243 to guide you through the process by determining which is the most appropriate Standard to use for the building's size and use. Page 23 of H1/AS1 defines which building uses are covered by the Acceptable Solution (the seven categories of building uses are defined by clause A1 of the Code and reproduced on page 7 of H1).
→ Buy NZS 4218:2009 Thermal insulation – Housing and small buildings
→ Buy NZS 4243.1:2007 Energy efficiency – Large buildings – Building thermal envelope
→ Buy NZS 4243.2:2007 Energy efficiency – Large buildings – Lighting
BRANZ seminars 2010 – Passive fire
Passive fire protection is an area that many find complicated and confusing. Passive fire protection measures are an incredibly important part of commercial and multi-unit residential building design and construction. Our next seminar examines the building element features of passive fire design. The seminar will help:
- architects and designers to realise the required fire resistance ratings
- builders to better understand the installation requirements
- building officials to be confident that the fire resistance ratings have been met
- Independent Qualified Persons to better understand their role in future building inspections.
Dates and locations are below. Registration will be open early in January at www.branz.co.nz.
- Monday 15 March – Dunedin
- Tuesday 16 March – Queenstown
- Wednesday 17 March – Christchurch
- Thursday 18 March – Wellington
- Monday 22 March – Auckland
- Tuesday 23 March – Hamilton
- Wednesday 24 March –Tauranga
- Thursday 25 March – Palmerston North
The following Standards are discussed in the seminars:
- AS/NZS 3837:1998 Method of test for heat and smoke release rates for materials and products using an oxygen consumption calorimeter
- AS/NZS 1905.1:1997 Components for the protection of openings in fire-resistant walls – Fire-resistant doorsets
- AS/NZS 1530.3:1999 Methods for fire tests on building materials, components and structures – Simultaneous determination of ignitability, flame propagation, heat release and smoke release
- NZS 4520:XX (under development)
- AS 4072 .1 :2005 Components for the protection of openings in fire-resistant separating elements – Service penetrations and control joints (email enquiries@standards.co.nz or call 0800 782 632 to order this Standard)
- AS1530.4:2005 Methods for fire tests on building materials, components and structures – Fire-resistance test of elements of construction(email enquiries@standards.co.nz or call 0800 782 632 to order this Standard)