Part One of our review into the 2019 edition of the NCC focuses on changes made to the Fire Safety provisions.
As most people would be aware, a large portion of a building surveyors assessment is dedicated to preventing the spread of fire between buildings on the same allotment,buildings on adjacent allotments and to an allotment boundary. In all previous editions of the Code, the housing provisions have only provided a deemed-to-satisfy building solution to achieve the fire safety performance requirements. There was no option for a building surveyor to address an acceptable construction manual and all building solutions outside the deemed-to-satisfy needed to be addressed by a fire engineer or similar suitably qualified professional.
The 2019 edition of the code has introduced a set of verification methods addressing the fire safety performance requirements. Below is a summary of the verification methods with regards to Class 1a and Class 10a buildings that are deemed equal to or greater than the deemed-to-satisfy provisions;
- Class 1a dwellings on the same allotments when the external walls and openings in the external walls of the dwelling, less than 1.8 metres from another building or 900mm from an allotment boundary, are capable of withstanding 92.6kW/m2 of heat flux for 60 minutes and the external walls extend to the underside of a non-combustible roof covering or non-combustible eaves lining in accordance with BCA.
- Class 10a to avoid the spread of fire between building on adjoining allotment is verified when it is calculated that a building will not cause heat flux in excess of those set out in column 2 at locations within the boundaries of an adjoining property set out in column 1 where another building may be constructed and when located at the distances from the allotment boundary set out in column 1.
- Class 10a to avoid the spread of fire between buildings on the same allotment is verified when it is calculated that a building is capable of withstanding the heat flux set out in column 2 without ignition and will not cause heat flux in access of those set out in column 2, when the distance between the building Is as set out in column 1.
Previously, a building that could not achieve the required separation distance was required to have an external wall and openings achieving an FRL 60/60/60 (or otherwise for openings) in accordance with the relevant Australian Standards. The verification method now provides an additional avenue where it may be excessive or unachievable for the building to meet the specific design of a fire resistance level. The heat flux calculations of the building should still be completed by a suitable qualified professional and reviewed by a qualified building surveyor.
If you would like more information on how the verification method may benefit your next project please contact one of our building surveyors on 0411 648 159 or via e-mail admin@specialisedbuildingsolutions.com
Further information on fire safety and other building surveyor matters can be found on our website www.specialisedbuildingsolutions.com
Columns mentioned above and verification methods can be viewed under Part 2.3 of BCA at the below link https://ncc.abcb.gov.au/ncc-online/NCC/2019/NCC-2019-Volume-Two/Section-2-Performance-Provisions/Part-23-Fire-Safety
