An extension is how most people get more house without giving up a street they already like. On the Sunshine Coast that usually means one of three things: pushing out at ground level, adding a floor above what you already have, or opening the house up to a deck or outdoor room. Each one solves a different problem, sits on a different structural footing, and takes a different approval path through your council.
Roebuck Concepts is a QBCC-licensed building company (licence 15280811) working from Unit 1/18 Lomandra Place, Coolum Beach, across the Sunshine Coast and Noosa Shire. Tom Roebuck holds his own individual QBCC licence (15015060) and has more than 20 years in residential construction. We are Master Builders Queensland members, and our extension at Coolum Beach won three 2025 Master Builders Queensland Sunshine Coast Housing & Construction Awards. Here is how extensions actually work in this part of Queensland.
Ground floor, second storey or outdoor room — which extension suits your house?
Ground-floor extensions
Extending out is generally the simplest structural job. You are adding new footings and a new slab or subfloor next to what exists, tying into the existing roof, and cutting an opening through an external wall that becomes an internal one. The constraints are almost always horizontal: how much clear ground you have to the boundary, where the sewer and stormwater run, what trees are protected, and how much of the lot is already built on. On the older sloping blocks around Coolum, Yaroomba and Ninderry, a ground-floor addition often needs a stepped slab or a suspended floor rather than a flat pad, and that decision is made by the engineer, not the plan.
Second-storey additions
Going up preserves your garden and your setbacks, which on a tight beachside lot can be the only option left. It is the harder build. You are removing a roof, exposing the house to weather, loading a structure that was never designed for a floor above it, and adding a stair that eats into the ground-floor plan you currently live with. It is also where boundary and height rules bite hardest, because setbacks in Queensland increase with wall height.
Decks, outdoor rooms and pavilions
Sometimes you do not need more house — you need the house to open properly. A covered outdoor room, an extended deck or a poolside pavilion adds usable living area for a fraction of the structural work of a habitable addition. It still needs approval. Sunshine Coast Council states that a deck, pergola, verandah, patio or balcony requires a development building work permit if it exceeds 10m² in area, exceeds a mean height of 2.1m and a maximum height of 2.4m, exceeds 5m in length on any side, or is 1.0m or higher above the surface level below. The council also requires a permit for any handrail or balustrade that protects a fall of 1.0m or more, and for stairs involving a change in levels of three risers, or 1.0m or more.
Can your existing slab and footings carry a second storey?
This is the first question we ask, and it is not answered by looking at the house. A slab poured for a single-storey home was designed for single-storey loads on the soil classification of that lot. Adding a floor above changes the load path through every wall and footing beneath it.
The honest answer comes from three things: a soil test to classify the site, a structural engineer’s assessment of the existing slab thickness, edge beams and reinforcement, and physical investigation — cutting inspection holes, exposing footings, checking stump condition on a pole or post-and-beam house. Coastal Sunshine Coast sites bring their own variables: reactive clays inland of the beach ridges, sandy profiles closer to the coast, high water tables, and salt exposure that shortens the life of unprotected steel.
The outcome is one of three. The existing structure takes the new load as it stands. It takes it with targeted work — underpinning, new piers, thickened footings, or steel transferring load to new points. Or the sensible answer is to build out rather than up. We would rather tell you that at the design stage than after demolition has started.
How do boundary setbacks and site cover limit what you can add?
Two layers of rules apply. The first is state-wide: the Queensland Development Code sets design and siting standards, with MP1.1 covering single detached housing on lots under 450m² and MP1.2 covering lots of 450m² and over. These parts govern boundary setbacks, site cover and height. Setbacks are not a single fixed number — they scale with the height of the wall you are proposing, which is exactly why a second storey often needs to sit further from the boundary than the ground floor already does.
The Queensland Government published an updated Queensland Housing Code on 14 August 2026, with a transition period running from 1 September 2026 to 1 September 2029 while local governments amend their planning schemes to adopt it. Until a council makes that amendment, the superseded Queensland Development Code parts continue to apply in that area. That means the siting rules applying to your extension depend on when you lodge and which council you are in, so we confirm the current position for your lot before design work starts.
The second layer is your planning scheme. Across the Sunshine Coast Council area, the Sunshine Coast Planning Scheme 2014 regulates the way land, buildings and structures are used and developed. Noosa Shire Council runs its own scheme, The Noosa Plan 2020, originally adopted in July 2020 to guide the shire through to 2040 and amended most recently by minor amendment No. 3, which commenced on 20 March 2026. Noosa’s controls on height, character and vegetation are distinctly its own, and an extension design that clears comfortably at Marcus Beach may need rethinking at Noosa Heads.
How do you match an existing roofline and cladding?
A good extension should not read as an extension. Matching comes down to four things: roof pitch and the plane the new roof meets the old on; fascia and gutter profile; cladding module, whether that is a weatherboard cover width, a sheet reveal or a render finish; and window sightlines, so head heights align across old and new.
Exact matches are not always available. Profiles get discontinued, colours weather, and older houses were built to dimensions no longer manufactured. Where a seamless match is impossible, the better move is a deliberate junction — a recessed shadow line, a change of material at a corner, or a linking element that reads as intentional rather than as a failed copy. We work this through at design stage, on site, with the existing material in hand.
Can you live in the house during an extension?
Often yes, and it depends far more on the type of extension than on the size of it. A ground-floor addition that is separated from your living areas by an existing wall can usually be built around you: the wall stays until the new structure is watertight, then comes out in a short controlled break.
A second storey is harder, because the roof has to come off. That exposes the entire ground floor to weather, disconnects wiring and plumbing, and creates dust and noise directly above where you sleep. Some clients stay through it with temporary weather protection and a staged program; many choose to move out for the roof-off period and return once the new floor is closed in.
The decision belongs in the contract, not in conversation. Before we start we agree in writing which rooms stay in use, where the temporary kitchen and bathroom will be, how site access and safety fencing separate the work zone from your family, and what the sequence is for each stage. Staying on site is cheaper than renting, but it is also slower — the program has to allow for it, and we price it that way rather than discovering it later.
What did we learn on the Grandview Drive extension at Coolum Beach?
Grandview Drive is a pole home at Coolum Beach that we extended in every direction — out, up and down — rather than pushing in a single line. It won three 2025 Master Builders Queensland Sunshine Coast Housing & Construction Awards, presented on 15 August 2025 at The Events Centre in Caloundra: Home Renovation/Remodelling Project over $1 million, Best Residential Swimming Pool for the figure-eight pool built on stilts, and Best Use of Innovation.
The lesson from that job applies to far smaller extensions. On a steep coastal block, the structure you already have dictates the extension you can build. Working with the existing pole frame rather than against it is what made a multi-directional addition and a suspended pool possible on a site where a conventional cut-and-fill approach would have been fought at every level.
What is the approval path for an extension in Queensland?
Most extensions need two separate things. Building approval is a development building work permit, issued by a private building certifier who assesses compliance with the Building Act, the National Construction Code and the Queensland Development Code, and who inspects the work at set stages. Sunshine Coast Council confirms that alterations and additions to existing dwellings require approval, and that a private building certifier can advise whether you need a permit and lodge the application on your behalf. Planning approval is separate and belongs to council, and it is triggered when your design does not meet the standards in the code or the planning scheme.
The order matters. Noosa Shire Council is explicit that a building application requiring a variation to the requirements of the Queensland Development Code or the local planning scheme must be submitted to Council prior to the building certifier granting approval, via a Request for Referral Agency Response. Noosa also states that building certifiers are not permitted to design the building or carry out any of the work. So a boundary relaxation or a height variation is a council decision that has to land first.
Our normal sequence is: measure and investigate the existing structure, concept design, soil test and engineering, siting check against your council’s scheme, any referral agency application, certifier lodgement, then a signed written contract before anyone lifts a tool.
How are extension contracts and warranty handled in Queensland?
The QBCC requires a written contract for domestic building work priced over $3,300 including labour, materials and GST. There are two levels for renovation and extension work: a Level 1 contract for work priced from $3,301 to $19,999, and a Level 2 contract for work priced at $20,000 and over. The contract must be written, signed and dated by all parties, and comply with Schedule 1B of the QBCC Act. Where the work is priced at $20,000 or more, the QBCC also requires the building contractor to give you a copy of the QBCC consumer building guide before you sign.
Insurable residential construction work is also covered by the Queensland Home Warranty Scheme. The QBCC requires the principal contractor to take out that cover on the homeowner’s behalf before residential construction work starts. It protects you if the work is left incomplete, if defects are not fixed, and for subsidence.
We do not publish a price per square metre, because it would be meaningless for your house. What drives the number is site access and slope, the soil classification, whether the existing structure needs strengthening, the length of the tie-in to the existing roof, whether services have to be relocated, the specification you choose, and whether the design needs a council variation. Those are the things we cost, on your lot, before you sign.
Extensions across the Sunshine Coast and Noosa Shire
We build extensions from Coolum Beach out through Yaroomba, Marcus Beach, Ninderry, Cotton Tree, Pelican Waters, Noosa Heads and the surrounding Sunshine Coast and Noosa Shire. Completed projects across these areas include Redwood Avenue at Marcus Beach, Hastings Street at Noosa, Elouera Drive at Ninderry, Kara Court at Yaroomba, Memorial Avenue at Cotton Tree, Columba Place at Pelican Waters and Nairana Rest at Noosa Heads.
If your project is more about reworking what you have than adding to it, see our renovation builders Sunshine Coast page, or the local detail on home renovations in Coolum Beach. If the extra space needs to be self-contained, a granny flat or detached space may do the job with less disruption to the main house.
Frequently asked questions about home extensions on the Sunshine Coast
Do I need council approval for a home extension on the Sunshine Coast?
You need building approval — a development building work permit — for alterations and additions to an existing dwelling, and Sunshine Coast Council notes that a private building certifier can advise whether a permit is needed and lodge the application for you. You need separate council planning approval only if the design does not comply with the Queensland Development Code or your planning scheme, for example a reduced boundary setback or extra height. In Noosa Shire, that variation must be submitted to Council before the certifier can grant building approval.
Can I add a second storey to a slab-on-ground house?
Sometimes, but never assume it. A slab and its footings were designed for the loads of the house that sits on them and the soil classification of that lot. Whether it can carry a second storey is determined by a soil test, a structural engineer’s assessment of the existing slab and footings, and physical investigation on site. The answer may be yes as-is, yes with underpinning or new piers, or no — in which case extending outward is the better project.
How close to the boundary can I build an extension in Queensland?
It depends on your lot size and the height of the wall. The Queensland Development Code sets siting standards, with MP1.1 applying to lots under 450m² and MP1.2 to lots of 450m² and over, and required setbacks increase as wall height increases. Your council’s planning scheme can add further controls. A design that does not meet the acceptable setback is not automatically refused, but it needs a council variation before the certifier can approve it.
Does a deck or outdoor room need building approval?
Sunshine Coast Council states that a deck, pergola, verandah, patio or balcony requires a development building work permit if it exceeds 10m² in area, exceeds a mean height of 2.1m and a maximum height of 2.4m, exceeds 5m in length on any side, or is 1.0m or higher above the surface level below. A handrail or balustrade protecting a fall of 1.0m or more requires approval, as do stairs involving a change in levels of three risers, or 1.0m or more. A small, low structure that sits under all of those triggers may not need a permit — your building certifier will confirm for your design.
Can I keep living in the house during the extension?
Usually yes for a ground-floor extension, where the existing external wall stays in place as a barrier until the new structure is watertight. It is harder for a second storey, because removing the roof exposes the whole ground floor to weather, and many clients move out for that period and return once the new floor is closed in. We agree the arrangement in writing before work starts, including the temporary kitchen and bathroom, site access and the stage sequence.
How long does a home extension take on the Sunshine Coast?
We do not quote a standard duration, because the honest answer depends on your approval path and your structure. The variables are how long the certifier and, where needed, council take to assess; whether existing footings need strengthening; the length of the tie-in to the existing roof; and the availability of matching materials. We build a program specific to your job and put it in the contract rather than quoting a generic figure.
Do you build extensions in Noosa Shire as well as the Sunshine Coast?
Yes. Our office is at Coolum Beach and we work across both council areas. It matters which one you are in: Noosa Shire is governed by The Noosa Plan 2020, adopted in July 2020 and amended most recently by minor amendment No. 3, which commenced on 20 March 2026, while the rest of the coast falls under the Sunshine Coast Planning Scheme 2014. The two schemes treat height, character and vegetation differently, so we check your specific lot before drawing anything.
What does a Queensland extension contract have to include?
The QBCC requires a written contract for domestic building work priced over $3,300 including labour, materials and GST — a Level 1 renovation, extension and repair contract from $3,301 to $19,999, and a Level 2 contract at $20,000 and over. It must be written, signed and dated by all parties and comply with Schedule 1B of the QBCC Act, and at $20,000 or more you must be given the QBCC consumer building guide before you sign. For insurable work, the principal contractor must also take out Queensland Home Warranty Scheme cover on your behalf before construction starts, which protects you if work is left incomplete, if defects are not fixed, and for subsidence.
Talk to a licensed extension builder at Coolum Beach
If you are weighing up building out against building up, the useful first step is a look at what you already have. Book a consultation and we will walk the site with you, talk through what the existing structure can take, and set out the approval path for your lot. Call 0477 333 386 or email tom@roebuckconcepts.com.au.