How big can a granny flat be in SA?

In South Australia, ancillary accommodation is typically limited to a maximum floor area (often 60-80sqm depending on your zone and block size). The dwelling must also meet setback and site coverage requirements specific to your location.

Can I rent out my granny flat?

Yes, granny flats can be rented out in most cases. However, check your approval conditions as some may restrict occupancy to family members. Rental granny flats are subject to residential tenancy laws and may have tax implications.

How long does it take to build a granny flat?

Construction typically takes 3-6 months once approvals are in place. Add 2-4 months for design and approval processes. Total timeline from decision to completion is usually 6-12 months.

Which builders build granny flats in Adelaide?

Granny flat and secondary-dwelling work in Adelaide splits into two camps. Smaller specialist builders often carry standard granny flat plans they can tailor to your block. Some volume and project builders will also design a fit-for-site secondary dwelling if it complements a knockdown-rebuild or infill development. Ask each shortlisted builder for two or three completed granny flats within the last 12 months, and verify their SA building licence and current Building Indemnity Insurance under the Building Work Contractors Act 1995.

Can I build a granny flat before the main house is finished, or on a battle-axe block?

Yes in some cases, but it depends on the zone, block size, existing dwelling status and council overlays. Some SA councils treat a granny flat on a battle-axe or subdivided block as its own separate dwelling for approval purposes rather than as ancillary accommodation. Confirm the planning pathway with your local council and PlanSA before you commit to a design, so the plan you buy is actually approvable on your specific block.

Project Type Guide

Granny Flat Builders Adelaide

Your guide to building a secondary dwelling

Ready to start? Find a builder in 60 seconds

Tell us your build type, state and rough budget and we'll match you with Adelaide builders that fit your project. Free, and builders contact you.

What are you building?

Where?

Rough budget?

Free · no obligation · builders contact you, never the other way around.

Granny flats (also called secondary dwellings or ancillary accommodation) are one of the fastest-growing building segments in Adelaide. Whether for ageing parents, rental income, or a home office, building a granny flat requires specialist knowledge of council requirements and compact design.

What is a Granny Flat?

A granny flat is a self-contained dwelling on the same block as a main house. In South Australia, they're officially called 'ancillary accommodation' and must meet specific planning rules. They typically include a bedroom, bathroom, living area, and kitchenette, ranging from 40-80 square metres.

Benefits

Multi-generational living with independence
Rental income potential ($250-$400+ per week)
Adds value to your property
Home office or teenager retreat
More affordable than buying a second property
Keeps family close while maintaining privacy

Considerations

Must comply with SA Planning & Design Code
Block must meet minimum size requirements
Setback and site coverage rules apply
May need approval from council
Services (water, power, sewer) must connect to main dwelling or separately
Not all blocks are suitable for secondary dwellings

Granny Flat Costs Adelaide 2025

Basic 1-bed (40-50sqm)$120,000 - $180,000

Standard 2-bed (60-70sqm)$180,000 - $250,000

Premium finish (70-80sqm)$250,000 - $350,000+

Costs vary significantly based on site conditions, finishes, and whether services need extending. Get multiple quotes.

The Process

Site Assessment

Check if your block suits a secondary dwelling

Design

Create plans that meet code requirements

Council Approval

Lodge development application if required

Builder Selection

Get quotes from experienced granny flat builders

Construction

Typically 3-6 months depending on complexity

Connection

Connect services and obtain occupancy certificate

What to Look For in a Builder

Experience with secondary dwelling approvals

Understanding of SA Planning & Design Code

Portfolio of completed granny flats

Fixed-price contracts available

Can handle site challenges (slope, access)

Offers design service or works with your plans

How long does it REALLY take to build a new home?

28m 57s

Watch: same topic on Home Building HubSponsored by

How long does it REALLY take to build a new home?

In this episode we explain how long it can take to go from a signed contract to a site start, and then how long to allow for your build time as well. We explain the reasons for the timeframes and why it is often so difficult to get a final completion date commitment from your builder too.

Watch full episode

Common Questions

Most granny flats require development approval in South Australia. Some may qualify as 'complying development' for faster approval if they meet specific criteria. Check with your local council or a planning consultant before proceeding.

Ready to Start Your Project?

Get independent advice on finding the right builder for your granny flat project.

1300 885 919

Other Project Types

Dual Occupancy Adelaide Townhouse Builders Adelaide Custom Home Builders Adelaide

We use cookies to improve your experience. Cookies on. Learn more