CDC vs DA in NSW: The Summer Holiday Decision Guide

Use CDC if your site is eligible and you meet every numeric standard. Use DA when flexibility or merit-based assessment is required. Start with zoning, confirm CDC exclusions, then run a numeric audit (lot size/width, height, FSR, setbacks, POS, landscaping, parking, overshadowing/privacy).

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PLanland CONCEPT [/caption]

Who this is for

Homeowners and small residential developers planning secondary dwellings, duplexes/dual occupancies, terraces, or first-floor additions—and using the holiday downtime to prepare a clean approval pathway.

Step-by-step decision flow (15 minutes)

• Confirm zoning and use: Find your zone (R2/R3/R4) and the proposed land use (e.g., “dual occupancy” or “secondary dwelling”) is permitted with consent.

• CDC eligibility check: Is your development type listed as complying development and is the site free of CDC exclusions (heritage item/area, certain bushfire/flood categories, etc.)?

• Numeric audit: Lot size/width, height, FSR, setbacks, private open space, deep soil, landscaping, parking, overshadowing/privacy.

• Pathway call:100% compliant + not excluded → CDC.

• Any shortfall or exclusion → DA (or redesign).

• Documentation plan: Assemble the right reports once; avoid “incremental” submissions that cause delay.

Quick comparison

FactorCDCDAAssessment styleStandards-based (binary)Merit-based (balanced)FlexibilityLowHigherTypical timelineFast once pack is cleanLonger; subject to referrals & submissionsBest forGranny flats, standard duplexesComplex sites, variations, heritage/constraints

“Holiday homework” checklists

CDC pack

• Title, 10.7 certificate, survey with contours/services
• Architectural set (plans/elevations/sections/shadows/privacy)
• BASIX/NCC where required
• Stormwater concept (OSD/connection)
• Specialist inputs only if triggered (e.g., BAL within CDC allowances)
• Completed certifier checklists

DA pack

Everything above plus Statement of Environmental Effects, any required studies (heritage/traffic/acoustic/flood/arborist), and a clear variation/merit story if needed.

Frequent pitfalls (fix now)

• Lot width shortfalls killing CDC for duplexes
• Driveway gradients/garage geometry not checked early
• Private open space/deep soil under provisions for terraces/manor houses
• Stormwater to legal point not feasible without OSD/easement
• Bushfire/flood constraints pushing you off CDC parameters

FAQs

Is CDC always faster than DA? Usually—if your documentation is precise.
Can I switch from CDC to DA? Yes; redesign for merit assessment.
Do I need neighbour consent for CDC? No; for DA, neighbours can make submissions.