Council — Sutherland Shire Council
Development — Residential, Dual Occupancy
Services — Stormwater management plan · On-Site Detention · Erosion & Sediment Control
Year — 2025
Outcome — Approved
Background
The owner planned to knock down the existing house and build a dual occupancy in its place.
The problem
The design had a basement, so it needed a pump-out system. It also had to be assessed for On-Site Detention (OSD). An OSD tank would have competed with the pump-out for space and added cost. It would also have meant one more structure to fit on a tight lot.
Our solution
We designed the basement pump-out, then looked at whether OSD was actually needed. We compared pre- vs post-development impervious areas. The comparison showed the development would only slightly increase the site’s impervious area, so the change was classed as minor. On that basis, OSD wasn’t proposed for the development, saving the owner a fortune in cost and space.
Was it approved? yes.
Basement Pump-out Detail