Complying development certificates: what NSW builders must check

A complying development certificate is one of the quicker approvals in New South Wales. When the proposed work meets the standards set in the state-wide codes, a council or an accredited certifier can issue a certificate without a full development application, and the job can move forward on the strength of it. For the builder that speed is a relief and also a trap, because a certificate issued quickly is still a set of conditions the builder has to live inside.

This article is about the builder’s side of the certificate: confirming the approval fits the job, meeting the conditions as the work progresses, and getting the paperwork to the certifier in the right order. It is separate from the wider planning pathways, which decide whether a project can use this route at all. The question here is what the builder does once the certificate is in hand.

The commercial stake is simple. Work started against a certificate that does not match the job can be stopped, the owner can be left with a building that needs retrospective approval, and the builder is the one who had the plans in hand. The cost of getting the check right is an hour on the first morning. The cost of getting it wrong is measured in redesign, delay and a conversation with the council that nobody wants to have.

Reading the certificate before anything else

The certificate is a document with a scope, and the scope is the first thing to read. It identifies the lot, the works approved and the stage of the project they cover. A certificate for a new dwelling is not automatically a certificate for a deck, a shed or a change to the roof, and a certificate that covers one part of a project does not cover the rest. Read the description of the works line by line against the job you are being asked to build, and be suspicious of any mismatch, however small it looks.

Check the date and the status too. A builder who starts work on a certificate that has lapsed, or on a modified version the owner has not passed on, is working on the wrong authority. Ask the owner or the certifier for the current version, and keep a copy on site that is the one the crew is working from.

The certificate and the building contract need to describe the same job. If the contract promises a particular house and the certificate approves a different floor plan or a different footprint, the mismatch becomes the builder’s problem the moment the owner points to the contract. Check the scope of the contract against the certificate before the price is locked in, and raise any gap at the start rather than halfway through the build.

Matching the stamped plans to what is on site

The approved plans are the drawings the certifier stamped as part of the approval. They are the reference for the building, and anything on site that differs from them is either a variation or a mistake. The trouble is that plans get revised, and a crew can end up working from a set that was superseded before the certificate was issued. Confirm the revision on the sheets on site against the approved set, and check the key dimensions, the setbacks and the floor levels against the plans before the slab or the first frame goes up.

Setbacks and levels are the items most often out. A house sited a fraction closer to the boundary than the plan shows, or a floor set higher or lower than the approval allows, becomes expensive to correct once the structure is finished. Set the pegs and check the levels against the stamped plans first, and record that the check was done.

Keep the stamped set in a form the whole crew can reach. A trade who works from a phone photo of an old sheet, or from a copy printed in the office some time ago, is working from a document that may no longer be the approved one. Put a revision block on the site set, check it at each stage, and make a habit of asking whether a sheet has changed before anything is cut to it.

Conditions that must be met before work starts

Most certificates contain conditions that have to be satisfied before any work begins. They are the easiest to miss because they are administrative rather than physical, and they often sit on the last page of a long document. The typical items are the appointment of a principal certifier, the notice of commencement given to the certifier and the council within the period the Act requires, the sign on the site identifying the certifier and the builder, and the home building compensation insurance under the Home Building Compensation Fund where residential building work above the threshold is carried out. Each one is a condition of the approval, and work started before it is met is work carried out without the approval in place.

Read the conditions as a checklist of tasks with their own owners, and assign each one before the first machine arrives. The notice of commencement is a common casualty, because it feels like paperwork and nobody is on site to remind anyone of it. The construction certificate conditions are covered in more depth in the article on construction certificate conditions, and the same habits apply across both. An hour spent sorting the start-up conditions in the week before works begin saves the awkward call from the council when a neighbour rings to ask why an excavator is on the block.

Some conditions are not about the start at all. They ask for things to be kept or done during construction, such as the hours of work, the control of noise and dust, the protection of trees that are to stay and the handling of stormwater. These are as binding as the start-up items, and a neighbour’s complaint is often the first sign that one has been missed. Read the full list at the start of the job, and put the ongoing requirements into the site induction for each trade.

BASIX is a list of things you must build

Where the work is covered by a BASIX certificate, the commitments made in it are part of the approval, and the builder is the person who delivers them. BASIX is the planning instrument that sets targets for energy and water use in new homes and certain alterations, and the commitments listed on the certificate describe the materials, systems and features the design depends on. The NSW Planning Portal explains how BASIX relates to planning approvals, and it is the reference to check when a commitment is unclear.

The practical rule is that a commitment is not met by a plan note. It is met by the thing in the building. Glazing that is specified must be the glazing installed, insulation must be the type and extent committed to, and any water or energy system must be the one listed. Keep a record of what was installed, with the product details, because the certifier will ask for it at the end, and it is much harder to reconstruct from memory once the walls are lined.

The commitments also affect the programme. Insulation, glazing and the water system arrive on site at set times and have to be in place before the lining or the finishes go on. Build them into the programme as fixed points, not as items that can be fitted in later, because the inspection of the lining depends on them being there.

Substitutions are where BASIX goes wrong. A supplier who is out of the specified window, or an insulation product that is cheaper and less effective, may look like a sensible change on the day. It is not. A change to a BASIX commitment is a change to the approval, and it has to go through the certifier before it is made.

Inspections and the paperwork the certifier needs

The certifier’s inspections are hold points. The work is meant to be inspected at the stages the approval sets, before it is covered, and the builder’s job is to give notice in time and to have the work ready when the inspector arrives. A slab covered over before the reinforcement is inspected, or a wall lined before the framing and wiring are checked, has to be opened again, and the builder pays for the opening.

The inspection process is covered in more detail in the article on what to expect from NSW building inspections. For the builder, the working habit is to treat every inspection as a stop sign and to keep the record of each one, with the date, the inspector and any items that were raised and closed. Those records, along with the product certificates, the engineer’s certificates and the other documents for the completed works, make up the file the certifier needs before the occupation certificate can be issued.

Ask the certifier in advance what each inspection will look at, and whether the inspector wants to see a particular item before it is covered. A short note on the job file, saying what was inspected, what was passed and what was raised, saves the later argument about whether a slab was checked before the pour.

Changes after the certificate is issued

Every change from the approved works is a question for the certifier before it is built. That includes the small ones that look harmless, such as a window moved a short distance, a deck made a little wider, or a roof pitch adjusted to suit a different tile. Some changes can be handled as a modification to the certificate. Others need a fresh application. The certifier decides which, and the builder’s role is to stop, ask and wait for the answer.

A practical habit helps here. Keep a running list of every request from the owner or the trades that touches the approved works, and mark each one as approved, refused or still with the certifier. The list shows at a glance whether anything has been built that is not on the approval, and it is the first thing the certifier will ask for if a question arises.

The temptation is to build first and sort the paperwork afterwards. That is the route to a building that cannot be certified as built, and it leaves the builder explaining to the owner and the council why the approved works were not what was built. Retrospective approval is possible in some cases, but it is slower, dearer and not guaranteed, and it is a poor thing to have to ask for on a finished house.

Worked example: a deck added to a certificate in western Sydney

A builder in western Sydney was engaged to build a dwelling addition under a complying development certificate. The owner also wanted a covered deck along the rear, which the certificate did not describe. The owner’s view was that the deck was a small thing, and that it could be added at the same time as the rest of the works without troubling anyone. The builder’s view, after reading the certificate, was that the deck sat outside the approved works, and he did not want to build it without the certifier’s answer.

He wrote to the certifier and asked whether the deck could be dealt with as a modification or would need an application of its own. The certifier’s answer was that it needed separate consideration, and that the deck could not be built until that was settled. The builder told the owner the deck would be treated as a separate job with its own approval and a later start, and he kept the main works moving in the meantime.

The cost of that decision was a short delay on the deck and an awkward conversation with the owner. The alternative was a deck built with no approval behind it, under the same certificate as the rest of the works, which would have caused problems for the occupation certificate and for the owner when they came to sell. The builder’s advantage was not special knowledge. It was the habit of reading the scope of the certificate before starting, and of treating a new request as a question for the certifier before it became a job.

The owner was not unreasonable, and the relationship survived the exchange. The useful part of the conversation was working out what the owner actually wanted from the deck, which turned out to be shade and somewhere to sit. That was put to the certifier as part of the separate application, and the builder could show the owner the sequence and the likely cost before anything was committed.

What to take onto the job

A complying development certificate is a fast route through planning, and it is only fast for the builder who respects it. Read the scope, check the plans on site, meet the start-up conditions before anything is dug, build the BASIX commitments in and keep the record, and stop to ask the certifier before any change is made. Those habits are not complicated, but they are the difference between a certificate that carries the job and one that is quietly unravelling under it.

The PointCPD guide to NSW builder CPD sets out how the regulatory side of the trade is kept current, which is the other half of working inside these approvals with confidence.

Questions builders ask

• Approvals
• Certification
• NSW Compliance

Published 24 September 2026. General information for builders, not legal, financial or engineering advice for a specific job. Check current requirements with the relevant regulator or standard before relying on them.