Service
Home extension and renovation builders
Adding to a house you already own — out the back, up a level, or through the whole thing.
- Licence checked
- Insurance sighted
- Solvency re-checked
When this is the right path, and when it is not
The existing house is structurally sound and in the right place, and you want more of it rather than a different one.
It is the wrong path where the structure is poor, the floor level is wrong, or the extension would be most of a new house anyway.
How the job actually runs
- 01Find out what the existing house is made of
Footings, frame, wiring and plumbing all constrain what can be added and what must be upgraded. An old house is a set of unknowns until someone opens it up.
- 02Check the overlays before you design
Heritage, character and vegetation controls bite hardest on extensions, because the assessment is against what is already there.
- 03Decide whether you move out
Living through a major extension is possible and it is harder than people expect. It also slows the build and therefore costs money.
- 04Expect provisional sums
No builder can price what is behind the walls of a sixty-year-old house without opening them. Insist those allowances are explained rather than buried.
Where these jobs go wrong
The four things that most often cost people money on a extensions job specifically.
- Assuming the existing footings will do
A second storey on footings never designed for one is the classic expensive surprise. It needs engineering assessment before design.
- Underestimating the join
Where new meets old is where extensions leak, crack and look wrong. It is detail work and it is not cheap.
- Thinking a renovation is cheaper than a rebuild
Sometimes it is. On a poor-condition house it frequently is not, and the comparison should be made honestly before you commit.
- Living through it to save money
The saving is smaller than people expect and the cost to your household is larger.
What moves the price
No figures — a number without your site and your specification is a guess. For a extensions job, these are what actually move it.
- Condition of the existing structure
- Matching or contrasting the existing house
- Bringing old services up to current standard
- Access for machinery and materials
- Whether you stay in the house
- Overlay and permit requirements
Where we cover this, and what the planning data says
Mapped constraints is the control that most often decides how a extensions job runs. Read from state planning data.
| Suburb | Council | Mapped constraints |
|---|---|---|
| Ainslie | ACT Government | 3 |
| Lyneham | ACT Government | 3 |
| Watson | ACT Government | 4 |
| Baulkham Hills | The Hills Shire Council | 3 |
| Carlingford | City of Parramatta Council | 1 |
| Castle Hill | The Hills Shire Council | 4 |
| Cherrybrook | Hornsby Shire Council | 4 |
| Cronulla | Sutherland Shire Council | 2 |
| Dee Why | Northern Beaches Council | 3 |
| Figtree | Wollongong City Council | 4 |
| Gordon | Ku-ring-gai Council | 2 |
| Jerrabomberra | Queanbeyan-palerang Regional Council | 1 |
| Killara | Ku-ring-gai Council | 2 |
| Lindfield | Ku-ring-gai Council | 2 |
| Manly | Northern Beaches Council | 4 |
| Merewether | City of Newcastle | 4 |
| Miranda | Sutherland Shire Council | 2 |
| Newcastle | City of Newcastle | 4 |
| Pymble | Ku-ring-gai Council | 2 |
| St Ives | Ku-ring-gai Council | 2 |
| Sutherland | Sutherland Shire Council | 2 |
| Turramurra | Ku-ring-gai Council | 2 |
| Wahroonga | Ku-ring-gai Council | 4 |
| West Pennant Hills | The Hills Shire Council | 4 |
| Wollongong | Wollongong City Council | 4 |
| Ascot | Brisbane City Council | 7 |
| Aspley | Brisbane City Council | 7 |
| Bulimba | Brisbane City Council | 7 |
| Carindale | Brisbane City Council | 9 |
| Clayfield | Brisbane City Council | 9 |
| Hamilton | Brisbane City Council | 10 |
| Hendra | Brisbane City Council | 8 |
| Indooroopilly | Brisbane City Council | 10 |
| Kenmore | Brisbane City Council | 9 |
| Mount Gravatt | Brisbane City Council | 6 |
| Nerang | City of Gold Coast | 8 |
| Paddington | Brisbane City Council | 7 |
| Rangeville | Toowoomba Regional Council | 2 |
| Sunnybank | Brisbane City Council | 7 |
| The Gap | Brisbane City Council | 7 |
| Malvern | City of Unley | 4 |
| Prospect | City of Prospect | 7 |
| Toorak Gardens | City of Burnside | 6 |
| Unley | City of Unley | 6 |
| Lenah Valley | Hobart | 8 |
| New Town | Hobart | 9 |
| Sandy Bay | Hobart | 8 |
| Balwyn North | City of Boroondara | 10 |
| Balwyn | City of Boroondara | 7 |
| Brighton | Bayside City Council | 10 |
| Camberwell | City of Boroondara | 10 |
| Canterbury | City of Boroondara | 6 |
| Glen Iris | City of Boroondara | 12 |
| Hampton | Bayside City Council | 8 |
| Hawthorn | City of Boroondara | 10 |
| Kew East | City of Boroondara | 11 |
| Kew | City of Boroondara | 11 |
| Newtown | City of Greater Geelong | 9 |
| Sandringham | Bayside City Council | 10 |
| Surrey Hills | City of Boroondara | 9 |
| Canning Vale | City of Gosnells | 0 |
| Claremont | Town of Claremont | 0 |
| Mount Tarcoola | City of Greater Geraldton | 0 |
| Nedlands | City of Nedlands | 0 |
| Thornlie | City of Gosnells | 0 |
Suburb-level, read from state planning data. Not a report on any individual block.
What to ask a builder about a extensions job
Specific to this kind of job. The general list is in questions to ask a builder.
- How will you tie the new structure into the existing footings and roof?
- What have you found behind walls on houses of this era?
- Can we live here during the works, and what is realistically liveable?
- How is the existing house protected and made weathertight during the works?
- What is your process when the scope changes after opening up?
Related
Questions people ask
Extend or knock down and rebuild?
It turns on the condition and layout of the existing house, and on whether heritage controls permit demolition at all. Anyone who answers without seeing the building is guessing.
Can I add a second storey to any house?
No. It depends on the footings, the frame and the planning controls. Get a structural assessment before you get attached to the idea.
Why are extension quotes so different from each other?
Usually because they assume different things about the existing structure. Compare the provisional sums, not the headline number.
The mechanism
One recommendation, not six quotes
We are a builder broker. Licence checked on the state regulator's own register, insurance sighted rather than self-declared, solvency re-checked on a schedule, and confirmed they take on extensions work in your suburb specifically.
Find home extension and renovation builders — free →
Free · about 3 minutes · no obligation · your details are never sold
The obvious questions
Why is this free to me?
Builders pay a success fee, the same rate across the network, and only once you sign. There is no premium placement to buy, so there is nothing for a builder to pay for beyond the work itself.
What if you don't have anyone for my area?
We say so, rather than send you someone we have not checked. The builder lists on our area pages are visibly empty where the network is empty.
Do you sell my details?
No. Your brief goes to the builder we match you with and to nobody else — not to a panel, not to a lead broker, not ever.
Am I committed to using them?
No. You get a recommendation and the reasoning behind it. There is no contract with us and nothing to cancel.
I already have a builder in mind.
Then check them yourself before you sign: the licence register for every state, and how to confirm they are still trading. Both take about five minutes and we would rather you did them than not.
More on how we are paid, what happens to your details, and how to check a builder yourself.
Home extension and renovation builders near you
Tell us about the job and where it is. We'll find builders who do this specific work in your suburb — or say plainly that we can't yet. Free to you: the builder pays us, and only if you sign.
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