Project Overview:
The Structural and Stormwater Design of this duplex development in Newcastle, NSW, exemplifies the synergy of architectural ambition and engineering excellence. The project integrates robust structural solutions with a fully compliant stormwater management system, tailored to local geotechnical conditions, coastal exposure, and municipal requirements.
Structural Design
- Foundations & Substructure:
- Reinforced concrete strip footings and slab-on-ground construction designed in accordance with AS 2870 (Residential Slabs and Footings).
- Geotechnical conditions, soil reactivity, and bearing capacity were carefully considered to ensure long-term stability.
- Superstructure:
- Load-bearing reinforced concrete walls, suspended slabs, and structural steel framing provide overall stability and efficient load transfer.
- Engineered timber is used for non-load-bearing partitions and lightweight roofing elements.
- Upper Levels & Roof:
- Suspended concrete slabs support first-floor living areas, cantilevered balconies, and planter features.
- Flat roof canopy and architectural overhangs are supported by concealed structural steel framing, designed to resist uplift and lateral wind forces per AS/NZS 1170.2.
- Lateral Stability & Seismic Design:
- Reinforced concrete shear walls, combined with diaphragm action of suspended slabs, provide lateral stability.
- Structural design incorporates seismic actions in compliance with AS 1170.4.
- Durability & Materials:
- All concrete elements are designed per AS 3600, with exposure classifications suitable for a coastal-urban environment.
- Structural steel is hot-dip galvanised or otherwise protected against corrosion.
- Masonry walls are detailed to AS 3700, incorporating control joints to accommodate shrinkage and thermal movement.
Stormwater Design
- Collection & Conveyance:
- Roof water is captured via gutters and downpipes and discharged into an underground stormwater system.
- Balcony and planter box drainage is integrated with the structure to prevent water ingress and façade staining.
- On-Site Detention (OSD):
- A detention system ensures that post-development peak discharge does not exceed pre-development levels, mitigating impacts on downstream networks.
- Water Quality:
- Pre-treatment measures, including grated pits, leaf guards, and first-flush devices, improve stormwater quality prior to discharge.
- Overland Flow:
- Safe overland flow paths are provided to accommodate extreme storm events, protecting neighbouring properties from adverse impacts.
- Compliance:
- Stormwater systems are designed in accordance with Australian Rainfall and Runoff 2019 (ARR2019) and Newcastle City Council guidelines.
Key Takeaway:
The Newcastle duplex demonstrates a holistic approach to residential design—where structural resilience, architectural elegance, and sustainable stormwater management are seamlessly integrated to deliver a safe, durable, and visually compelling living environment.
