DA vs CDC in Sydney’s Inner West - the step-by-step guide (with TRBS by your side)

If you’ve ever tried to figure out whether you need a Development Application (DA) or a Complying Development Certificate (CDC), you’ll know it’s not exactly light reading. Between Inner West Council’s heritage maps, lot‑size rules, and planning jargon, it’s easy to feel stuck before you even start. That’s where TR Building Solutions (TRBS) comes in, we guide you from first chat to green light, so you can build with confidence.

The 60‑second snapshot

·       There are three pathways in NSW: Exempt Development (no approval), Complying Development Certificate (CDC), and a full Development Application (DA).

·       Lot metrics matter: for a standard dwelling‑house CDC you generally need a lot size over 200m² and  a frontage over 6m wide at the building line (battle‑axe lots have extra rules).

·       Heritage reality check: if your place is a Heritage Item or inside a Heritage Conservation Area (HCA), CDC is often limited; design for DA early.

·       Certifier choice counts: your Principal Certifier (PC) manages mandatory inspections and your Occupation Certificate - TRBS coordinates this so nothing slips.

Understanding the three pathways (and where TRBS helps)

Exempt Development (no planning or building approval)

Some small, low‑impact works are approval‑free if they meet every standard in the State Environmental Planning Policy (Exempt and Complying Development Codes) 2008 (the Codes SEPP). Think small decks/patios, non‑structural internal works, sheds, certain carports, fences, driveway resurfacing, and maintenance like painting or window repairs. The catch: every numeric rule and site condition must be satisfied - heritage, flood, bush fire and front setbacks can flip the answer. TRBS can quickly sanity‑check your idea so you don’t over‑ or under‑apply.

Complying Development Certificate (CDC) - the fast‑track

CDC is a code‑based approval issued by Council or a registered certifier when your plans satisfy the Housing Code. We test height, setbacks, landscaped area, privacy/overshadowing, and site pre‑requisites. If you tick all boxes, CDC can combine planning + building approval in a streamlined path. TRBS prepares a ‘CDC‑ready’ pack and lines up your certifier so determination is smooth.

Development Application (DA) - the merit pathway

If CDC isn’t possible because of heritage, lot constraints, or you need design flexibility then we steer you into a DA with Inner West Council. This is where good design logic and a clear planning story wins. TRBS coordinates architects/designers and specialist reports, lodges via the NSW Planning Portal, and keeps things moving through requests for information (RFIs) and neighbour notification.

Step 1 - Measure your lot like it matters

The 200m² + 6m CDC baseline

For a standard dwelling (house) under the Housing Code, expect a minimum lot area of 200m² and a minimum lot width of 6m at the building line. Battle‑axe sites have extra dimensions (typically a 12m × 12m building envelope exclusive of the handle, handle widths also apply). Under this threshold, assume a CDC for a dwelling‑house is off the table and plan for a DA unless your exact works qualify as Exempt Development. TRBS validates these numbers up‑front so you don’t spend on drawings that can’t be approved.

Step 2 - Heritage & conservation areas (Inner West reality check)

Much of the Inner West sits within Heritage Conservation Areas (HCAs) and contains listed Heritage Items. That doesn’t stop great modern design - it means your proposal must respect streetscape rhythm, roof profiles, materiality and significant elements. CDC is often excluded or tightly limited in these contexts. TRBS runs a heritage screen early, briefs your designer to the right controls, and prepares the heritage justification you’ll need under a DA.

What work could be Exempt Development?

If, and only if, you meet every standard in the Codes SEPP. TRBS checks the fine print before you lift a hammer. Some examples that may be exempt are;

·       Small decks, patios and pergolas within height/setback/area limits

·       Non‑structural internal alterations (no change to structure or fire safety measures)

·       Garden sheds and some carports within strict size/height/location limits

·       Fences and minor driveway/paving works within standards

·       Maintenance like painting or window repairs (subject to heritage exclusions)

Note: Anything in the road reserve (e.g., a new driveway crossing/kerb) requires separate approvals. TRBS sequences those applications alongside your CDC or DA so your build doesn’t stall.

The CDC process - fast when you’re truly compliant

·       Pre‑check: TRBS runs a rule by rule Housing Code test (height, setbacks, privacy, landscaped area).

·       Pack: architectural plans, BASIX/NatHERS where applicable, engineering details and specifications.

·       Issuer: Council or a registered certifier - you choose.

·       Principal Certifier (PC) is appointed by you before construction; manages mandatory inspections and issues Occupation Certificate (OC).

·       Timeline: faster determinations when the application is complete and compliant - TRBS front loads compliance to save weeks.

The DA process - when design judgement and context matter

·       Due diligence: title/survey, services, heritage map, LEP/DCP controls, and site constraints (flood, trees, foreshore).

·       Design: sympathetic streetscape response, roof forms and materials; where a variation is essential, a robust planning argument.

·       Lodgement: NSW Planning Portal; Inner West Council will notify neighbours and assess against the LEP/DCP.

·       Post‑consent: you still need a Construction Certificate (CC) and PC appointment before works commence; inspections to Occupation Certificate.

·       TRBS role: we coordinate the team, answer RFIs, keep program pressure, and manage compliance evidence for inspections.

Local examples (the Inner West in real life)

• Annandale terrace: A rear ground‑floor addition qualified for CDC only after we reworked side setbacks and privacy screens. Missing one standard would have pushed it into DA - our pre‑check saved weeks.

• Leichhardt semi: a narrow block under 6 m at the building line meant CDC was off the table from day one. We shaped a DA with a sympathetic roof form and got it through on merit.

• Dulwich Hill heritage cottage: inside a Heritage Conservation Area, so we planned for a DA, kept the front roof and chimney intact, and modernised out back. Approval without the tug of war.

Certifier know‑how (and avoiding ‘missed inspection’ headaches)

Your Principal Certifier safeguards compliance. Miss a critical stage inspection and you risk delays, extra declarations, and even refusal of an Occupation Certificate. TRBS builds an inspection calendar, briefs trades, and assembles evidence so each inspection passes first time.

Quick triage - 3 questions TRBS asks on day one

·       What’s your lot area (m²) and width at the building line? If it’s under 200m² or under 6m at the building line, plan for a DA (unless your exact works are Exempt).

·       Is the property a Heritage Item or inside an HCA? If yes, CDC is usually limited - design to suit DA from the start.

·       Any constraints like flood, bush fire, significant trees or a new driveway crossing? These alter the path or add approvals.

Make it easy - bring TRBS in early

We run the numbers, check heritage, align the design to the correct code set, and manage certifier and council workflows. That’s how you get from idea to approval without detours.

Written by TR Building Solutions - we’re a Unrestricted licensed Class 2 builder based in Sydney’s Inner West, helping homeowners design, plan and build with confidence across the Inner West, Eastern Suburbs and Lower North Shore.

Information correct at time of publishing: Autumn 2025.