The NT Deemed to Comply Manual (DTCM) is referenced in the Building Code of Australia, Volume 2, Part 3.10.1 as an acceptable construction manual for high wind areas.
The Manual contains products or systems which have been assessed for structural adequacy for cyclonic wind loads and approved by the NT Building Advisory Committee (BAC). These drawings can be accepted by architects, builders, building certifiers, designers, engineers etc as complying with the structural requirements of the NT Building Act.
Manufacturers' specifications must be consulted for any non-structural issues such as waterproofing, safety etc.
Where drawings for a product or system comprise multiple sheets these will be indicated as sheet 1 of 3, sheet 2 of 3 and so forth.
Note that drawings marked as withdrawn are provided for reference only as they are no longer approved for use on new structures. Products or systems may have been withdrawn at the request of the manufacturer or because contact information has not been updated with the NT Building Advisory Committee (BAC).
A list of products added or removed over the past three months is provided on the search screen. To see a list of all products which have been withdrawn, select the status 'withdrawn' without any information in the other fields.
Please access the Deemed to Comply Manual via this link.
Although the Building Advisory Committee makes every effort to process applications for inclusion in the Deemed to Comply Manual as quickly as possible, the process is time-consuming both for applicants and committee members and the process takes at least six months from application to final decision.
To reduce delays, all applicants should ensure that their applications are complete, product sheets are prepared in accordance with the guidelines (with notes, limitations etc in the appropriate place on the sheet, and all supporting documents - in particular test results) are provided.
On receipt, all applications will be given a preliminary review to ensure that the layout is in accordance with the Committee’s requirements. Mistakes identified at this stage will need to be corrected before the application is referred to the Building Advisory Committee.
Any errors noted by the Building Advisory Committee will need to be corrected and the sheets re-certified before the sheets can be approved for inclusion in the manual.
Applicants must ensure that all details, references tables and calculations are correct before the sheets are certified and it is the responsibility of the certifying engineers to check that all details, references, tables & calculations are accurate before the sheets are signed and submitted to the Committee.
All applications for inclusion of products/systems must be made on the approved form and lodged with the Building Advisory Committee, together with all required supporting documentation.
Please download the application package here:
The “Low High Low” pressure sequence testing regime was introduced in the BCA 2006 from 1 May 2006 as the official testing mechanism for all metal roof products, cladding assemblies, connections and immediate supporting members, replacing the 10,000 cycle test used previously. Since that time the NT has dual referenced the 10,000 cycle and Low High Low systems to give industry the opportunity to move to the new testing regime. This dual referencing ended on 30 April 2009 and all products not supported by Low High Low pressure sequence test results were withdrawn from the Manual.
From 1 May 2009 any product to be retained in the Manual must be tested under the new regime (Low High Low) and the test results submitted to the Building Advisory Committee for consideration, as part of a complete new application. Where extrapolation of results is required, this should be provided in writing by the testing authority.
In accordance with BCA clause 22.214.171.124 (f) and table 3.10.1, all sheets referencing Low High Low testing should include reference to Australian Standard AS1170.2 and no reference should be made to AS4055.
Testing facilities for metal roofing products under the Low High Low system are available at various testing centres in Australia and New Zealand. Check out their web pages via links on our links page or see contact details.