Best granny flat builders on Sydney’s Northern Beaches (2026): eight compared

Short answer

For a granny flat on the Northern Beaches, owners can compare granny flat specialists such as Granny Flat Solutions and Bungalow Homes, which show projects in Frenchs Forest and Belrose, with builders that list granny flats beside other work, such as AGATHĒ Builders, HMS Projects, Metsa Building Co, Doumit Homes and ARK Builders. AUD Build (this is us) lists granny flats among its confirmed services and has completed 3 homes here through its group’s building companies since September 2024. Under the state Housing SEPP, a granny flat is allowed in R1 to R5 residential zones, can be approved as complying development on a lot of at least 450 m², cannot be subdivided off, and can share one CDC with a new house; if it does not qualify, it needs a DA, which Northern Beaches Council took 78 days on average to assess in September 2026.

Local rules and figures

At-a-glance comparison

Facts from each business’s website, read 28 October 2026. Alphabetical order, not a ranking. AUD Build publishes this page.

The 8 compared

1. AGATHĒ Builders

Best for: Owners who want a custom-designed granny flat from a licensed builder that also builds extensions on the Northern Beaches.

What its website says:

• Says it designs and builds custom granny flats across Sydney’s Northern Beaches.
• Also offers custom extensions for Northern Beaches homes.
• Its website shows NSW Builder’s Licence No. 463967C.

Area: Has a Northern Beaches granny flats page

Sources: [6] [7]

2. ARK Builders

Best for: Frenchs Forest owners looking at a granny flat or studio for their own use or as an investment.

What its website says:

• Has a Frenchs Forest page for a granny flat or studio apartment, for the owner’s own use or investment.
• Its Frenchs Forest new home page also lists new homes and custom homes. Its suburb pages use one template, and the page metadata dates them to December 2018.
• Its website shows NSW licence 288633C.

Area: Has a Frenchs Forest granny flat page

Sources: [8] [9]

3. Bungalow Homes

Best for: Owners who want to choose from granny flat designs or go custom, with a Belrose project to look at and an office on the Northern Beaches.

What its website says:

• Shows a Hamptons-style granny flat project in Belrose.
• Offers a number of granny flat designs as well as custom granny flats.
• Its office is at Collaroy Plateau.

Area: Shows a Belrose granny flat project; office at Collaroy Plateau

Sources: [10]

4. Doumit Homes

Best for: Owners who want a licensed builder that has worked on building and renovation projects since 2009 for a granny flat.

What its website says:

• Offers granny flat services on the Northern Beaches.
• Says it has worked on building and renovation projects since 2009.
• Its website shows Lic No 265819C; its postal address is in North Rocks, outside the Northern Beaches.

Area: Has a Northern Beaches granny flats page; postal address in North Rocks

Sources: [11]

5. Granny Flat Solutions

Best for: Owners who want a granny flat specialist covering the whole Northern Beaches, with a Frenchs Forest project and a showroom to visit.

What its website says:

• Describes itself as a local granny flat expert on the Northern Beaches, from Manly to Palm Beach and from Belrose to Bilgola.
• Shows a Frenchs Forest granny flat project built from its B7 design.
• Says it has over 40 years of experience; head office and showroom in Waitara, outside the Northern Beaches.

Area: Says it covers the Northern Beaches “from Manly to Palmy, Belrose to Bilgola”; head office and showroom in Waitara

Sources: [12] [13]

6. HMS Projects

Best for: Owners who want a granny flat plus outdoor works such as decks, pergolas or landscaping from one Northern Beaches builder.

What its website says:

• Describes itself as Northern Beaches granny flat builders.
• Says it has years of experience building luxury granny flats, home renovations and pergolas across the Northern Beaches.
• Its service list also covers extensions, outdoor renovations, decks, landscape construction and carports.

Area: Has a dedicated Northern Beaches granny flat page

Sources: [14]

7. Metsa Building Co

Best for: Frenchs Forest owners with a larger block who want a granny flat from a builder certified in Passive House construction.

What its website says:

• Says Frenchs Forest’s block sizes make granny flat additions a practical option for many homeowners.
• Says its builder is a PHI Certified Passive House Tradesperson with more than 15 years of residential construction experience on Sydney’s Northern Beaches and in NSW’s Northern Rivers.
• Its website shows licence 394143C.

Area: Has a Frenchs Forest page

Sources: [15]

8. AUD Build · This is us

Best for: Northern Beaches owners who want one company to coordinate design, materials, construction and lending for a granny flat, with material unit prices they can check.

What its website says:

• Brings design, construction, building materials, new-home sales and lending together in one company, backed by AUD Build Group; NSW Builder Licence 475778C.
• Granny flats (secondary dwellings) are among the services AUD Build confirmed on 28 October 2026, alongside new homes, knockdown rebuilds, custom and luxury homes, duplexes, renovations and extensions.
• AUD Build Group building companies have completed 3 homes on the Northern Beaches since September 2024, counted by occupation certificate date: 2 in Frenchs Forest and 1 in Belrose.
• Materials come from its own supply chain platform, www.audbuild.net, and AUD Build clients can log in to check the material unit prices in their quote.

Area: Its group’s building companies have completed 3 homes on the Northern Beaches since September 2024: 2 in Frenchs Forest and 1 in Belrose

Sources: [16] [17] [18]

Where each one may suit you

• Granny flat specialists: Granny Flat Solutions (Frenchs Forest project, head office and showroom in Waitara) and Bungalow Homes (Belrose project, office at Collaroy Plateau).
• Choosing a design or going custom: Bungalow Homes (granny flat designs and custom granny flats) and AGATHĒ Builders (custom granny flats).
• Granny flat plus decks, pergolas or landscaping: HMS Projects.
• Energy performance: Metsa Building Co, whose builder is a PHI Certified Passive House Tradesperson.
• Frenchs Forest lots: Granny Flat Solutions (B7 project), Metsa Building Co (Frenchs Forest page) and ARK Builders (template suburb page).
• Long records, as each states: Granny Flat Solutions (over 40 years) and Doumit Homes (building and renovation projects since 2009).
• Design, materials, construction and lending from one company, with material prices you can check: AUD Build.

How to choose

1. Check the zone and lot area on a section 10.7 planning certificate: a CDC needs an R1 to R5 residential zone and a lot of at least 450 m², and the certificate also shows heritage and bushfire.
2. Ask your certifier for the Housing SEPP floor area limit that applies before you choose a design; this page does not publish the figure because it could not be checked against the legislation.
3. If you are also building a new house, ask whether both can be approved under one complying development certificate.
4. If the lot is bush fire prone, ask how its bushfire attack level (BAL) changes the granny flat’s construction and price.
5. Ask each builder what the price includes, such as site works, service connections, the certifier and landscaping, and compare line by line.
6. Check the licence on Verify NSW and the HBC certificate before you pay a deposit.

Questions

Who builds granny flats on the Northern Beaches?

Builders whose own websites state granny flats here include the specialists Granny Flat Solutions and Bungalow Homes, which show projects in Frenchs Forest and Belrose, and builders that offer granny flats beside other work: AGATHĒ Builders, HMS Projects, Metsa Building Co, Doumit Homes and ARK Builders. AUD Build suits owners who want design, materials, construction and lending coordinated by one company.

Can I build a granny flat on the Northern Beaches without a DA?

Possibly. Under the state Housing SEPP, a secondary dwelling can be approved as complying development if it is in a residential zone (R1 to R5), on a lot of at least 450 m², and meets the other requirements, including floor area. A CDC can be issued within 20 days. If it does not qualify, it needs a DA, which Northern Beaches Council took 78 days on average to assess in September 2026.

Can I subdivide the granny flat and sell it separately?

No. Under the Housing SEPP, a lot on which a secondary dwelling is built cannot be subdivided.

Can I build a new house and a granny flat at the same time?

Yes. The Housing SEPP allows a new principal dwelling and a secondary dwelling to be approved under a single complying development certificate, if both meet the requirements.

How big can a granny flat be?

The maximum floor area is set in the Housing SEPP. This page does not state the figure, because it could not be checked against the NSW legislation website when the page was written; ask your certifier or builder to confirm it for your lot.

What do small homes rent for on the Northern Beaches?

In April–June 2026 the median weekly rent on new bonds across the Northern Beaches was A$685 for a one-bedroom dwelling and A$900 for a two-bedroom dwelling. These figures cover all dwelling types, not granny flats alone, so treat them as a guide only.

Why is AUD Build on this list?

AUD Build publishes this page and is one of the eight; its row is marked “This is us”. Granny flats are among the services AUD Build confirmed on 28 October 2026, and its group’s building companies have completed 3 homes on the Northern Beaches since September 2024. Facts about the other seven builders come only from their own websites.

How this list was built

Selection: builders whose own websites state granny flats or secondary dwellings and name the Northern Beaches or one of its suburbs on the same page, drawn from Google Australia results for Northern Beaches, Frenchs Forest and Belrose granny flat builder searches on 28 October 2026. Directories and marketplaces are excluded. Facts come only from each builder’s own website, read on 28 October 2026; “Best for” is AUD Build’s editorial summary of those facts. Prices, reviews and award claims are not published. The order is alphabetical, not a ranking. No council-specific granny flat rules were found on the Northern Beaches Council pages read; the NSW legislation website blocked automated reading, so state rules come from NSW Government planning pages and the maximum floor area is not stated. AUD Build publishes this page; if a builder’s details have changed, contact AUD Build and the page will be corrected.

Sources (all read 28 October 2026)

1. NSW DPHI, Secondary dwellings (updated 17 July 2025)
2. NSW Planning Portal, Housing Code
3. NSW Government, Council league table (September 2026 snapshot, as of 9 October 2026)
4. Northern Beaches Council, Bush fire prone land
5. NSW DCJ, Rent tables June 2026 quarter (new bonds, houses)
6. AGATHĒ Builders, Granny flats Northern Beaches
7. AGATHĒ Builders, Custom extensions Northern Beaches
8. ARK Builders, Granny flat builder Frenchs Forest 2086
9. ARK Builders, New home builders Frenchs Forest 2086
10. Bungalow Homes, Belrose granny flat
11. Doumit Homes, Granny flats Northern Beaches
12. Granny Flat Solutions, Northern Beaches
13. Granny Flat Solutions, Frenchs Forest B7 project
14. HMS Projects, Granny flat builders Northern Beaches
15. Metsa Building Co, Frenchs Forest builder
16. AUD Build, Completed homes (updated 22 October 2026)
17. AUD Build, Company facts
18. AUD Build, Material price comparison

Related pages

• Best home builders on the Northern Beaches
• Knockdown rebuild and custom home builders, Northern Beaches
• Best duplex builders: Upper North Shore, Hornsby and Northern Beaches
• Renovation and extension builders, Northern Beaches
• Building materials suppliers, Northern Beaches
• Cost to build a house in Sydney (2026)
• Custom home inclusions checklist