Regulations – buildings
Various Australian Standards apply to window film for buildings.
Compliance with Standards is mandatory when the Standard is referred to in legislation such as the National Construction Code (NCC). It is the obligation of the installer to be aware of, and comply with, the Standard/s relevant to his or her business. WFAANZ recommends every member obtain their own copy of the Standard/s relevant to their work, and reference the Standard in their day to day activities.
A summary of some Standards relevant to the window film industry follows. WFAANZ cautions this information is by no means comprehensive, you may need to comply with Standards other than these. This information is for reference only. It is always the window film installer’s responsibility to ensure compliance with all legal requirements for every project.
AS1288 GLASS IN BUILDINGS – SELECTION AND INSTALLATION
This Standard nominates the types of glass which must be used in different areas of buildings and types of buildings. It is referenced in the National Construction Code (NCC). The objective of the Standard is to provide uniform direction for the use and installation of glazing throughout Australia.
AS1288 covers many requirements such as the strength of balustrade glass, overhead glass, glass subject to wind loads, glass subject to human impact and much more, but the main area of concern to window film installers is human impact.
AS1288, Section 5, Criteria for Human Impact ensures safety glass is used in locations at risk of human impact. These locations include doors, low level windows, shopfronts etc. AS1288 also has specific sections dealing with glass in bathrooms, schools, aged care facilities, etc. so there is no ‘one size fits all’ approach when safety glass is required in any building.
Safety glass can be:
- Laminated glass
- Toughened/tempered glass
- Safety organic coated glass (annealed glass with safety film)
Annealed glass can be achieve Grade A safety glazing with safety window film.
There are maximum permissible pane sizes for different glass thicknesses. For example, a 3mm thickness pane may be safety filmed to attain Grade A status only if the pane is less than 2m2, if the pane is 6mm thickness then the pane can be up to 3m2, and so on.
When installing safety film for AS1288 compliance consider the following:
- Each pane must be labelled as being a safety glass. Window film distributors must provide you with AS2208 compliance stickers. These must be adhered to a corner of every pane, prior to the window film. Installing window film over the sticker ensures its permanency
- Some client’s may also ask you for a paper certificate of compliance. This is not an AS1288 or AS2208 requirement but WFAANZ distributor members will be able to provide you with this if required
- AS1288 requires most glass within 1m of the floor to be Grade A safety glass. This means that if the bottom of the glass pane is within 1m of the floor then the whole pane must be filmed. Do not install a strip of film along the bottom of the pane to cover just the glass area that is within 1m of the floor
- AS1288 has a section entitled ‘Making Glass Visible (Manifestation)’. The purpose of this requirement is to help avoid people walking into the glass because they can’t see it. This is common on glass doors, walls, etc. An opaque window film may be installed as a strip across the glass and this can also be computer cut with logos or decorations. Clause 5.19 covers what is permissible in detail. A word of caution, buildings where the BCA requires access for people with disabilities have different requirements for manifestation and these are detailed in AS1428.1.
Window film installers cannot conduct glass safety audits for their clients. Only certified building inspector or engineers are qualified for this. It is important you advise the client you are offering your opinion on which glass you believe should be window filmed in accordance with AS1288, but you are not qualified to provide a formal audit. It must remain the client’s responsibility to ensure compliance via a building inspector or engineer.
Window film provides an excellent option for building owners needing to increase the safety of their glass without the expense of glass replacement and in turn AS1288 offers a great opportunity for window film installers. Remember though, we’re talking about safety and in many cases the safety of children, so AS1288 must not be taken lightly… get a copy!
AS/NZS 2208 SAFETY GLAZING MATERIALS IN BUILDINGS
It is important installers understand AS2208 and how it relates to AS1288.
It sets out the test requirements for the classification of safety glazing materials for use in buildings. The test requirements are designed to promote safety and reduce/minimise the chance of cutting and piercing injuries. This applies to all safety glazing materials for compliance with AS1288. The impact test assesses the fracture characteristics of a safety glazing material that has been broken under test conditions.
There are two types of safety glazing certification specified in AS2208, Grade A and Grade B. Grade A is the higher level certification. Many window film manufacturers have attained Grade A safety glazing certification for their 100 micron (4 mil) safety films and thicker.
Certification of window films to AS2208 requires both an Impact and a Weathering test.
The impact test simulates the impact from a child’s head if the child was at running speed. A large pane of annealed glass with safety film is held vertically in a frame and a lead shot bag is swung on a pendulum arm, hitting the centre of the pane. To pass the test the film must limit the size of any holes made in the pane and hold the glass shards together, so the risk of cutting is minimised.
The pane is subject to impacts on both the filmed side and the unfilmed side of the glass and must pass the impact test on both sides to attain certification.
The weathering test is designed to prove the safety film will still have satisfactory adhesion and tensile strength years after installation. This test subjects film samples to high levels of light exposure in a special weathering chamber. Following weathering, weathered and unweathered samples are tested for adhesion and tensile strength and the weathered samples must prove to have a minimum percentage of adhesion and tensile strength compared to the unweathered samples.
Product compliance to AS2208 is the responsibility of the window film distributor, not the installer. It is also the responsibility of the distributor to provide safety labels, as detailed in AS1288.
This Standard regards the structural design of buildings and this part, AS/NZS 1170.2, concerns wind actions. The most common application of window film in this Standard is window film for cyclonic wind protection.
The requirements for cyclonic wind protection are very tough. A window representing the actual, size, glass, frame and window film construction is submitted for testing. The testing typically involves laying the window horizontally and dropping a heavy wood batten from a height end first, this is to simulate an airborne object hitting the window in a cyclone. The batten is then dropped numerous times at different locations. After all impacts the pane is inspected for penetrations and subjected to a compressed air test, if no air penetrates then the window has passed.
Cyclones are naturally severe, and the harshness of the test means the glazing system must withstand impact from heavy airborne missiles and continue to provide an airtight membrane. It is commonly regarded that the most severe damage in a cyclone occurs not from airborne missiles but from the air pressure inside when the building fabric is breached.
The NCC, BASIX and Energy Efficiency
The National Construction Code (NCC) is a uniform set of technical provisions for the design and construction of buildings and other structures throughout Australia.
Manged by the Australian Building Codes Board (ABCB) on behalf of the Federal and State governments, it calls up relevant Australian Standards that outline compliance requirements.
Compliance with the NCC is mandatory, and it nominates requirements for minimum building energy efficiency for both residential and commercial buildings.
At this point in time only NSW requires energy efficiency measures for residential buildings outside of those required in the NCC and this program is called BASIX.
Window films play an important role in building energy efficiency. By reducing heat entering the building they help cooling loads, and in retaining heat within a building they help heating loads.
The thermal efficiency of any building is a complicated calculation relying on many aspects like the floor, walls, roof and window materials, building shape, location, usage, etc. It is impossible to know the net effect on the building’s energy efficiency by considering just one aspect in isolation, such as glazing.
The NCC and BASIX both have thermal efficiency calculation methods for buildings and from that calculation the requirements of the glazing can be determined. Target U-Value and SHGC figures are provided, and window film installers can then match a window film product to those requirements.
Matching a film for a residential or commercial application is as simple as selecting a WERS rated film with a U-Value the same or lower than the target value, and an SHGC +/- 10% of the target value.
WERS ratings are a whole of window rating, which is the mandatory requirement for residential applications under NCC and BASIX. NB: you cannot use the standard values on film manufacturer product information cards.
Under the New Zealand Building Act 2004, all building work must comply with the New Zealand Building Code. The mandatory provision for safety glass is contained in Building Code clause F2 hazardous Building Materials. One way of complying with the performance criteria is to follow the Department of Building and Housing’s F2 Compliance Document, which cites NZS 4223: Glazing in buildings, Part 3 Human impact safety requirements: 1999.
For more information visit www.building.govt.nz.
Glazing must also be considered under Building Code clause B2 Durability which requires a 5 year durability if:
(i) the building elements (including services, linings, renewable protective coatings, and fixtures) are easy to access and replace and
(ii) Failure of those building elements to comply with the building code would be easily detected during normal use of the building.
Standards New Zealand has published a revised Standard specifying Thermal insulation – Housing and small buildings, NZS 4218:2009, which supersedes NZS 4218:2004.
Note: NZS 4218:2004 continues to be cited in the Compliance Documents for the New Zealand Building Code.
NZS 4218 specifies thermal insulation requirements for housing and small buildings for users of the Standard – architects, designers, building consent authorities, and window and glass companies.
‘The Standard is also useful for the building industry including window and glass manufacturers, insulation manufacturers, and manufacturers and suppliers of building products so that they can provide advice and stock appropriate products,’ says Michael Camilleri, committee Chair, from BRANZ. ‘Ambiguities in the previous version of NZS 4218 have been resolved, and there is additional guidance with more worked examples.’
The revised version of NZS 4218…
- includes modified R-value tables and brings the Standard into line with these increased performance requirements. The construction R-values in this Standard result in a low life cycle cost, based on current knowledge of insulation costs, energy costs, and heating behaviour
- clarifies the three different ways of working out R-values (Schedule method, Calculation method, and Modelling method) and ensures consistency between the different methods
- includes clearer definitions.
Some of the most significant changes are:
- adjusted R-values to reflect improved energy efficiency
- changes to the calculation method to ensure adequate thermal performance is not compromised by large glazing areas
- a revised modelling method to take account of recent research, and to make it easier to use with recent computer modelling packages
- new requirements for high thermal mass construction to ensure that the thermal mass is adequate and effective
- a revised appendix (now Appendix C) on windows and glazing
- a new informative Appendix D provides guidance on alterations and how they can achieve higher thermal resistance
- more worked examples in informative Appendix F
- the new term construction R-values has been introduced to distinguish the performance values in this Standard from insulation material R-values.
Allan Sage, Glass Association of New Zealand Technical Advisor: “There is more clarity on the use of doors, skylights, decorative glazing, and louvres. Appendix D – Windows and Glazing has been revised, offering more glazing options and guidance for users wanting to calculate other glass and frame combinations. A new term (RWindow) has been introduced to overcome confusion over the R-value for glass only (RCOG) and the total window R-values (RWindow).
“The major change for the window industry is the reduction of the limit on glazing area from 50% to 40% for the Calculation method. The Modelling method must be used for a glazing area over 40% of the total wall area. This will see more modelling of complex houses in the future, which GANZ believes is a positive move to stop over-heating and under-heating issues with modern house design,” Allan continued.