Building and wind suitability guide
Class 1, Class 10 and AS4055 suitability limits
Building classification and AS4055 suitability are separate questions. QuickFrame10 is for complete structural documentation for suitable Class 10 buildings. QuickWind is for a standalone AS4055 certificate for suitable Class 1 or Class 10a projects.
By Dominic (Son Hai) Nguyen, Senior Structural Engineer · Last reviewed
NER 4070460 · NSW Design Practitioner DEP0003685 · RPEQ 23510
Direct answer
First confirm the formal building classification. Choose QuickFrame10 when a suitable Class 10 building needs structural design. Choose QuickWind when AS4055 is appropriate and only the site wind classification certificate is required.
Class 1 buildings
In practical terms, Class 1 generally covers houses and similar residential dwellings, including detached houses and some attached dwellings such as townhouses. Formal classification depends on the NCC and the project circumstances.
Class 10a buildings
Class 10a generally includes private garages, carports, sheds and similar structures. QuickFrame10 can also include studios and workshops where the proposed use is NCC Class 10.
QuickFrame10 suitability
QuickFrame10 is for Class 10 buildings with ordinary domestic loading, including studios or workshops where the proposed use is NCC Class 10 and household vehicle parking where relevant. The new structure must have its own supports, bracing, tie-down and load path to the ground. It may adjoin or attach to an existing building without structurally relying on it.
The paid design service resolves the applicable wind basis and structural system for the new building. The intended use is clarified during the included remote consultation. Formal classification and approval decisions remain with the relevant certifier or authority. Existing-building assessment uses a separate scope.
AS4055 suitability and geometric limits
AS4055 only applies where the building fits within the relevant pathway and geometric limits. These can include matters such as building height, eave height, roof pitch, building width and the relationship between building length and width. This page does not reproduce the Standard.
Before ordering QuickWind, confirm that the building is Class 1 or Class 10a and suitable for AS4055. QuickWind then provides the standalone site wind classification certificate for the nominated site.
Other project pathways
Work involving structural reliance on an existing building, existing-condition assessment, unusual loads or a different building use needs separate consideration. Use the fee proposal form for other structural engineering work.