Somerset covers the Brisbane Valley: Fernvale and Lowood in the south, Esk and Toogoolawah up the valley, Kilcoy in the north, and the farmland and acreage around Wivenhoe and Somerset dams. Granny flats here sit under the Somerset Region Planning Scheme Version 5.0, which commenced on 4 June 2026 with Major Amendment 2. Checked October 2026.
Somerset asks for more than most SEQ councils. The lot has to be at least 800 m², and in most zones a granny flat needs a development application to council before the certifier can approve the building. The good news is on cost: council doesn't charge infrastructure charges on a secondary dwelling.
| Rule | What it says |
|---|---|
| Minimum lot | 800 m² |
| Maximum size | 60 m² GFA on lots under 2,000 m²; 90 m² on 2,000 m² or more. In the Rural zone, 90 m² from 2,000 m² to 5 ha and 120 m² over 5 ha |
| Position | No closer to the street than the house, and close to it; no fixed distance |
| Height | Two storeys and 8.5 m |
| Setbacks | 10 m front, 4 m side and rear and 20% site cover in the Rural residential and Emerging community zones and the Park residential precinct; 15 m all round in the Rural zone; Queensland Development Code elsewhere |
| Parking | Three spaces for the house and granny flat together |
| Driveway | Same crossover as the house; in the Rural zone a second crossover is allowed on another road frontage or more than 100 m from the first |
| Approval | Code assessment (a development application) in the Township, Rural residential, Rural and Emerging community zones; accepted development in the General residential zone if it meets the code |
| Infrastructure charges | None for a secondary dwelling |
When you need a development application
The tables of assessment make a new secondary dwelling code assessable in the Township, Rural residential, Rural and Emerging community zones, and impact assessable in the Centre zone. Code assessment means a development application for a material change of use, assessed against the dwelling house code, before the building approval. In the General residential zone a dwelling house, including a secondary dwelling, is accepted development if it meets the code; if it misses one of the rules, the certifier refers the building application to council.
Infrastructure charges
None. Somerset's Charges Resolution (No. 1) 2026, in effect from 19 August 2026, says adopted charges don't apply to a material change of use or building works for a secondary dwelling. The 2025 resolution said the same. Urban Utilities can levy its own water and sewer charges separately from council, so ask Urban Utilities on a serviced lot.
Overlays to watch
Flood comes first. The scheme maps extreme, high, significant, low and potential flood hazard areas. A dwelling house in any of them meets the flood hazard overlay code or becomes code assessable. The code keeps buildings out of the extreme flood hazard area or lifts them above the defined flood level, which for habitable rooms the scheme sets at the 1% AEP flood plus 500 mm where a flood line has been approved, or the highest recorded flood where it hasn't. The scheme also sets freeboard at 300 mm above the defined flood level. There is no temporary flood instrument in Somerset.
Bushfire: the overlay maps potential impact buffer and medium, high and higher potential bushfire intensity areas. A dwelling house there is accepted development if it meets the bushfire hazard overlay code and code assessable if it doesn't. These same areas are the bushfire prone area for the building rules, so expect a BAL assessment.
Somerset is drinking water catchment country. The catchment management overlay applies within 400 m of a waterbody or 100 m of a watercourse in the higher risk catchment area, and 150 m and 75 m in the lower risk area, and brings the biodiversity and catchment codes with it. On an unsewered lot that matters for the wastewater system. Agricultural land is mapped too, but the agricultural land overlay leaves a dwelling house as accepted development. Landslide, scenic amenity and stock route overlays round out the list.
Getting a granny flat in on a Somerset block
Water and sewer: Urban Utilities in town, tanks out of town
The Queensland Government lists Urban Utilities as the water and sewerage provider for Somerset. Inside the water connections area the code has the dwelling connect to reticulated water, and inside the wastewater connections area to sewer. Outside them, each dwelling needs at least 45,000 litres of drinking water storage, or 10,000 litres when connected to an approved bore, not counting any bushfire water, and an approved on-site wastewater treatment system.
If a sewer or water main runs through the yard, Urban Utilities needs no referral when every footing load sits at least 300 mm below the pipe and the whole building ends up at least 3 m clear of its centreline, or 5 m for driven piles. Closer than that, the certifier lodges a Build Over Asset referral with certified structural drawings and the engineer's Form 15.
Typical blocks and crane access
Fernvale and Lowood have newer estates with suburban lots, and not every one clears the 800 m² minimum, so check the lot area on the title first. Esk, Toogoolawah and Kilcoy have older town lots with wider streets. Outside the towns, acreage is the norm. The crane has room on most of it, but the truck still has to get there: long gravel driveways, creek crossings and soft ground after rain can mean a smaller truck or a longer crane reach. Check overhead power along the road and the route over any causeway before booking.
Rural and acreage rules
In the Rural zone the dwelling house itself needs a lot of at least 4,000 m² with frontage to and access from a formed road on council's road register, and all weather access to each dwelling. The size cap climbs with the land: 60 m² under 2,000 m², 90 m² up to 5 ha and 120 m² above that. Setbacks are 15 m from every boundary with 20% site cover. Any new dwelling sits at least 500 m from an existing intensive animal industry or extractive industry, unless it's part of that operation.
Rules that apply across Queensland
- You can rent a granny flat to anyone, not only family. The state removed the family-only test in September 2022. It still has to be secondary to the main house and can't be sold separately.
- You always need a building approval from a licensed certifier, and a plumbing approval from council.
- Queensland's new Housing Code started on 1 September 2026 with new setbacks. Each council keeps its current rules until it adopts the new code, by 1 September 2029 at the latest.
As at October 2026, Somerset has not adopted the Housing Code. The state's Housing Code page names no adopting councils, and council's planning scheme amendments page lists Major Amendment 2 as the latest change, with no Housing Code amendment.
What to check on a block
The zone and whether it needs a development application, the 800 m² minimum, the size cap for the lot, every overlay with flood and catchment first, whether the lot is inside the water and wastewater connections areas, the slope, and whether a truck and crane can get in.
What an install costs in Somerset
Most installs run $59,000 to $140,000 inc GST, on top of the price of the home. Somerset saves on infrastructure charges but adds a development application in most zones, with its fees and time. Outside the connections areas, tanks and an on-site wastewater system roughly double the plumbing line. Flood levels can lift the floor, and long rural driveways add to delivery and crane time. A flat town lot with sewer nearby lands towards the lower end.
Questions about granny flats in Somerset
What's the minimum lot size for a granny flat in Somerset?
800 m². It's an acceptable outcome of the dwelling house code, so a smaller lot misses the code and the application goes to council.
How big can a granny flat be?
60 m² of gross floor area on lots under 2,000 m² and 90 m² on bigger lots. In the Rural zone it's 90 m² from 2,000 m² to 5 ha and 120 m² over 5 ha.
Do I need a development application?
In the Township, Rural residential, Rural and Emerging community zones, yes: a secondary dwelling is code assessable. In the General residential zone, no, if it meets the dwelling house code; you need building and plumbing approval only.
Does Somerset charge infrastructure charges on a granny flat?
No. Charges Resolution (No. 1) 2026 says adopted charges don't apply to a secondary dwelling. Urban Utilities may levy its own water and sewer charges.
Can the granny flat have its own driveway?
In town, no: it uses the house's crossover. In the Rural zone it can have its own crossover on a different road frontage, or more than 100 m from the house's crossover on the same frontage.
Can I rent it out?
Yes, to anyone. State law has allowed renting a granny flat to anyone since September 2022. The code still treats it as part of one dwelling house, subordinate to the main house, and it can't be sold separately.
Read next
- Queensland granny flat rules, explained
- Owner builder or licensed builder on a modular home
- Renting out a granny flat
- Bushfire ratings explained
- What a granny flat costs in SEQ
- Free block check
- Granny flats in Ipswich
- Granny flats in Lockyer Valley
- Granny flats in Moreton Bay
Homes that fit a typical lot in Somerset
60 m² GFA under 2,000 m² (90 m² over, 120 m² on rural lots over 5 ha), but the lot must be at least 800 m², so a 600 m² lot misses the code. A typical 600 m² lot is too small. On a 800 m² lot that means up to 60 m². These are the lowest installed prices among the 140 homes from 25 m² to that size on the site, on an easy block, with homes the maker says are Class 1a first.
See all homes up to 60 m² Check your own block
Rule from Somerset's planning rules, checked October 2026. Installed prices are estimates on an easy block, inc GST. Your block decides the real number.
- Somerset Region Planning Scheme Version 5.0 (dwelling house code 8.2.6, tables 5.5 and 5.9)
- Somerset, Somerset Region Planning Scheme
- Somerset, planning scheme amendments
- Somerset, Charges Resolution (No. 1) 2026
- Somerset, development application fees and infrastructure charges
- Somerset, zone and overlay maps (eServices property enquiry)
- Queensland Government, secondary dwelling changes
- Ministerial statement, Queensland Housing Code
- Department of Housing and Public Works, Queensland Housing Code
- Business Queensland, SEQ water and sewerage service providers
- Urban Utilities, build or construct over or near pipes or easements
- Urban Utilities, Build or Construct Over Asset referral checklist
- Queensland Parliament, Question on Notice 1574 (2023), secondary dwelling utilities and charges