Sydney/Granny Flat Certifier
Building certifiers · Sydney, NSW

Granny Flat Certifier Sydney

A granny flat is one of the more straightforward projects to get approved in New South Wales, provided it meets the rules for a secondary dwelling. Vast Consulting Group is a registered certifier based in Botany, assessing and certifying granny flats for homeowners, builders and developers across Sydney. We know where these projects usually trip up and how to keep them on the faster approval path where possible.

Get a free quote (02) 9821 2062
Granny Flat Certifier Sydney

How it works in New South Wales

Secondary dwellings, commonly called granny flats, are dealt with under the Housing SEPP as complying development in most cases, meaning they can be approved through a Complying Development Certificate (CDC) rather than a full Development Application. To qualify, the secondary dwelling generally needs to sit on the same lot as the principal dwelling and meet size and lot limits, commonly cited as a maximum floor area of around 60 sqm and a minimum lot size of around 450 sqm (check current limits with us). Where a project does not meet these standards, for example because the lot is smaller or the design exceeds the floor area cap, it may need to go through council as a Development Application followed by a Construction Certificate instead.

Once building work is underway, a Principal Certifier carries out the required inspections, and an Occupation Certificate is needed before the granny flat can be occupied or rented out.

The process with Vast

01

Send us your site details and concept plans

We check your lot size, existing dwelling and proposed floor area against the Housing SEPP standards to confirm eligibility for a CDC.

02

Assessment and approval

Where the design meets the standards, we assess the application and issue the Complying Development Certificate.

03

Inspections during construction

As your Principal Certifier, we carry out the critical stage inspections as the granny flat is built.

04

Occupation Certificate

Once construction is finished and compliant, we issue the Occupation Certificate so the granny flat can be legally occupied.

What we check

Floor area of the proposed secondary dwelling against the current cap
Lot size and whether it meets the minimum required for a granny flat
Setbacks, height and site coverage under the Housing SEPP
Separation and privacy between the granny flat and the principal dwelling
Parking, if required for the site
Bushfire, flood or other site constraints that could rule out a CDC
Whether the project needs a DA and CC pathway instead of a CDC

Areas we cover

We certify granny flats and secondary dwellings across the Sydney metropolitan area, including the Bayside, Randwick, Inner West, Canterbury-Bankstown, Georges River, Sutherland, Liverpool and Parramatta council areas. If your site is elsewhere in New South Wales, contact us and we will confirm whether we can take on the project.

FAQs

How big can a granny flat be in Sydney?

Under the Housing SEPP, secondary dwellings are commonly limited to around 60 sqm of floor area, though this depends on the specific provisions that apply to your site (check current limits with us before finalising your design).

Can I rent out my granny flat?

In most cases, yes, subject to any specific conditions on your approval. Send us your plans and intended use and we will confirm what applies to your property.

Do I need council approval for a granny flat, or can a certifier approve it?

Most granny flats that meet the Housing SEPP standards can be approved directly by a registered certifier through a Complying Development Certificate, without going to council for a Development Application.

What if my lot is too small for a CDC granny flat?

If your lot does not meet the minimum size or your design does not meet the floor area cap, we can talk you through whether the project could instead proceed as a Development Application and Construction Certificate.

Call our Sydney office on (02) 9821 2062 or send your site details through our contact page for a quote. Read more on our blog about Sydney granny flat rules, and if your granny flat project is in Queensland, our Brisbane team can help instead.

You dream it. We approve it.

Send us the drawings. We'll tell you what it takes to get approved.

Get a free quote
Vast Consulting Group

Unrestricted building surveyors and certifiers. Residential, commercial and industrial. Brisbane and Sydney.

Brisbane Unit 4, 211 Logan Road
Woolloongabba QLD 4102
(07) 3112 7689 Also serving the Gold Coast and Sunshine Coast
Sydney · Head office Level 1, 1401 Botany Road
Botany NSW 2019
(02) 9821 2062
Follow info@vastconsulting.com.au
© 2026 Vast Consulting Group Pty Ltd Licensed under the QBCC Act · Registered certifiers, Building Commission NSW