Custom home structural engineering — Byron Bay.
Case study: structural engineering and drafting for a 480 m² custom home on a sloping site in the Byron Bay hinterland — engineered timber portals, exposed steel framing and reactive-soil pad-and-beam footings to AS 2870 and AS 1684.
Project overview
ASTCAD provided structural engineering and drafting for a 480 m² architect-designed custom home on a sloping reactive-clay site in the Byron Bay hinterland. The brief required exposed engineered timber portal frames, large cantilevered floor sections and a primary axis aligned to the view rather than the property setback.
The challenge
The reactive Class P site, combined with a 6 m fall across the building footprint, ruled out a slab-on-ground solution. The architect required visible timber portals at the ends of a 9 m cantilever and large unsupported floor spans for an open-plan living area — all while meeting cyclonic-region wind on the exposed ridge.
Our approach
- Pad-and-beam footing design to AS 2870 for reactive Class P soil
- Glulam portal frame design with FEA-validated connection details
- Cantilever floor design using LVL beams with deflection limits at L/600
- Cyclonic Region B wind loading per AS/NZS 1170.2
- Structural integration with passive solar and exposed-services architecture
Deliverables
- Foundation plans with concrete schedule and reinforcement details
- Floor and roof framing plans with bracing layouts
- Glulam portal shop drawings and connection details
- Steel framing details for exposed elements
- Engineering certificate for council and CDC certifier
Outcome
The home was completed within 11 months of structural sign-off. The engineered timber portals — fabricated off-site and craned in — became the defining architectural feature. No structural rework or RFIs were issued during construction.