Alterations and additions

When is no approval needed?

Exempt work needs no approval. But it must meet every state rule for that work, be structurally sound and comply with the building code. It cannot be done on land holding a State Heritage Register item, or land covered by an interim heritage order.

A kitchen or bathroom update can be exempt. But changing the layout, even removing a non-loadbearing wall, usually takes it out of exempt work. Windows and doors needed for light and air must not be made smaller.

Asbestos may be present in any home built before 1990. Not sure of your home's age? Get a licensed asbestos assessor to check before any wall or ceiling is opened.

When can you get a CDC?

Internal changes can get a CDC (a fast-track approval from a certifier) if they do not change the building's class, create a separate home, add a floor inside, or convert a basement into habitable space. An attic conversion must stay within the existing roof, without changing its pitch.

In a heritage conservation area, outside changes cannot touch the wall facing the street or make the house taller. Additions must meet the state fast-track rules for setbacks, height and landscaping. Those rules only cover land zoned RU5 or R1 to R4, so we confirm your zoning first.

What about the existing house?

The current building code governs the new work. It does not automatically follow that the existing house must be lifted to today's standards. That said, NSW law already requires a working smoke alarm on each level of a home, including levels with no bedrooms. A renovation is a good time to check. Fire and Rescue NSW also recommends one in every bedroom.

Before adding a level or removing walls, an engineer usually needs to check what the existing footings, beams and framing can carry. This may mean opening a ceiling or exposing a footing to see the real sizes. The findings and any strengthening should be in the engineering lodged with your application.

Do you need BASIX?

You need a BASIX certificate if the estimated cost is $50,000 or more. A pool or spa with a capacity of at least 40,000 litres triggers BASIX too. If the design changes, update the BASIX certificate before lodging the new plans. Revising a valid certificate already lodged is free.

Dealing with work that was never approved

Council, not a private certifier, handles past work that never had approval. The usual tool is a building information certificate, which the owner, or a buyer under a contract for sale, can apply for. It does not approve or legitimise the old work. Instead, it prevents council from issuing orders to fix, pull down, change or rebuild the work it covers.

For unauthorised work done before the certificate is issued, that protection has no end date. For issues caused purely by fair wear and tear, it lasts 7 years. A development consent cannot approve work after it has been built, so a consent or modification can only cover future use or new work.

Council can ask for plans, a survey report and certificates from engineers or trades to support the application. If your addition will join onto or rely on unapproved work, such as an enclosed verandah or a converted garage, settle its status first, so the new work is not built onto something council could later order removed.

Owner-builder permits and builder insurance

To do or manage the work yourself, you need a permit as an owner-builder when the job is worth over $10,000 and requires a DA (development application) or CDC (complying development certificate). The value is the reasonable market cost, counting both labour and materials. At higher values, an owner-builder course is also required.

Generally a person can be issued only one permit in any five year period. A second permit is possible for the same land, or where special circumstances exist. Permits are not issued to renovate an apartment, unit, flat or townhouse within a strata complex. Electrical, plumbing, gasfitting, air-conditioning and refrigeration work still needs a licence holder.

When a licensed builder takes on a job priced above $20,000, GST included, you must receive a home building compensation certificate from them before any deposit is taken or work begins. This applies to alterations and renovations as well as new homes, so ask for the certificate before you pay anything.

Extensions near Sydney Water pipes

An extension can end up on or beside a water or sewer pipe crossing the yard. Sydney Water says that where work needs building approval from council or a certifier, its own approval is also required, and it names home extensions and swimming pools as examples of work where it checks and approves the building plan.

Lodgement is online, using the Tap in service. An extension sitting close to or over a pipe gets passed to a water servicing coordinator, who assesses it in more detail.

Having the service diagram in hand early lets the designer shift the extension or adjust its footings while that is still simple, not after lodgement.

Wet area rules for renovated rooms

A like for like bathroom or laundry update can be exempt from approval, but the work must still comply with the NCC (National Construction Code). That includes the Housing Provisions rules for wet areas, which apply whether or not a certificate is needed.

Beside a bath that is not freestanding, the wall must be water resistant to 150 mm above the bath where the bath is within 75 mm of it. The junction between wall and floor along the bath must be waterproof. In a laundry, the wall around the washing machine taps must be water resistant for 75 mm above and to each side of them.

Laundry and toilet floors must be water resistant, as must the junctions between their walls and floors. A toilet with a handheld bidet spray needs a waterproof floor. Inset kitchen sinks need water resistant edges and wall junctions, and tap holes through a benchtop must be waterproof.