Duplex Design & Approval Services in Sydney
Maximise your block's value with a custom duplex design — from site feasibility to DA/CDC approval. BDAA-accredited, Registered Design Practitioner.
In brief: Most NSW councils require 400–500m² minimum for duplexes. giantA runs an 8-source feasibility check using NSW Planning Portal, SIX Maps, and council LEP/DCP data before advising.
Is Your Site Suitable for a Duplex?
Square metres alone don't determine viability. giantA assesses eight data sources before advising:
| # | Check | Source | What It Tells You |
|---|---|---|---|
| 1 | Zoning & planning | NSW Planning Portal | Is duplex permitted? |
| 2 | Physical land data | NSW Spatial Portal | Dimensions, slope workable? |
| 3 | Boundaries & easements | SIX Maps | Easements reduce buildable area. |
| 4 | LEP & DCP controls | Local council | Min lot size, FSR, height limit. |
| 5 | Hazards & constraints | Planning Certificate 10.7 | Flood, bushfire, heritage. |
| 6 | Legal encumbrances | Section 88B, Title Search | Covenants, restrictions on subdivision. |
| 7 | Exact measurements | Registered Survey Plan | Exact boundary dimensions. |
| 8 | Professional assessment | giantA feasibility review | Is a duplex viable on your block? |