ACT planning rules for secondary residences.
The ACT Territory Plan, the Crown Lease conditions, and the development pathways for granny flats explained. Inner-North, Inner-South and Tuggeranong each have distinct rules. Here’s the framework.
The 2026 rules.
- Maximum GFA: 60m² (some zones 80m²)
- Block minimum: 350m² (most residential zones)
- Setbacks: 3m rear, 1.5m side, 6m front (Plus existing dwelling setback rules)
- Maximum height: 4.5m to top of ridge
- Site coverage: Combined existing dwelling + granny flat must not exceed 50% of block
- Permeable surface: 25% of block minimum must remain permeable
- EER (Energy Efficiency Rating): 6-star minimum (in addition to NatHERS 7-star NCC requirement)
- Solar orientation: Living area should face within 30° of true north where possible
- Heating system: Required (gas, hydronic, or reverse-cycle electric)
The lease-condition issue (Inner North + South).
ACT residential blocks are leased Crown land (not freehold). The original Crown Lease conditions may restrict what you can build, and pre-1990s leases sometimes contain “single dwelling” restrictions that prevent secondary residences without a formal lease variation.
Affected suburbs commonly:
- Ainslie, Reid, Braddon (Inner North)
- Forrest, Red Hill, Griffith (Inner South)
- Yarralumla, Deakin (older blocks)
For these blocks, lodge a Lease-Conditional Approval (LCA) first — varies the lease to allow secondary residence. $1,840 fee, 4–8 weeks turnaround. We coordinate the LCA application.
The three development pathways.
1. Exempt development.
For minor structures (under 25m², ancillary use only). NOT available for habitable secondary residences. Effectively only covers garden sheds.
2. Code-compliant Development Application.
Standard pathway for most granny flats. Must meet all code rules (height, setback, coverage, GFA). ~$1,200–$1,800 application fee, 4–8 weeks turnaround. Most builds qualify.
3. Merit-track Development Application.
For builds requesting variation from code (e.g. larger GFA, reduced setback). Adjoining-owner consultation required. $1,800–$2,800 + 12–20 weeks turnaround. Higher risk of objection or refusal.
What “6-star EER” actually means.
The ACT requires every new dwelling to achieve EER 6 stars (Energy Efficiency Rating). EER is calculated from the building’s thermal model: insulation values, glazing performance, orientation, shading. It’s different from NatHERS but related.
To achieve 6 stars in Canberra’s cold winters:
- Double-glazed windows throughout (single-glazed = automatic fail)
- R5.0 wall insulation
- R6.0 ceiling insulation
- Slab edge insulation (R1.0)
- Air-tightness compliance (less than 10 ACH₀₅)
- North-facing living areas where possible
- Eaves or overhangs to provide summer shading
We design to EER 6.5+ as a buffer — provides headroom against minor design changes during build.
What we handle for you.
- Crown Lease conditions check (Day 1)
- Lease-Conditional Approval if needed
- Feature + contour survey commissioning
- NatHERS thermal model + EER report
- Shadow diagram (mandatory for ACT)
- Architectural drawings + Development Application
- Adjoining-owner consultation
- Building Approval via Registered Private Surveyor
- ActewAGL + Icon Water service connections
- Certificate of Occupancy at handover
Where we work.
Free Crown Lease check.
Send us your address. We’ll check the lease conditions and tell you which pathway suits, within 48 hours.