Cost estimates for extensions, alterations and renovations, including the hidden costs that often surprise homeowners.
Renovations and additions are harder to price than new builds. Demolition, making good, protecting what stays, and connecting new work to old all add cost, and they are easy to underestimate.
Our estimate looks at the whole job so you can plan a realistic budget, check a builder's price, or support a funding request.
Who this is for
- Homeowners planning an extension or major renovation
- Investors renovating a property
- Owners reviewing a builder's renovation quote
- Lenders funding alterations to an existing home
What is included
Strip-out and demolition
Allowances for removal, protection and disposal.
Connecting new to existing
Costs for structural alterations, tie-ins, weathertightness and making good.
Services upgrades
Electrical, plumbing and drainage upgrades often triggered by new work.
Finishes and fixtures
Priced to the level of specification you actually want.
Contingency
A realistic contingency, because older buildings often hide surprises.
Scenario options
We can price alternatives so you can see how design choices affect the budget.
Documents we will ask for
- Existing and proposed plans
- Specification or finishes schedule
- Photos of the existing building
- Builder's quote (if you have one)
- Any building condition reports
Not sure what you have? Send what is available and we will confirm exactly what is needed.
How it works
- Share the plans and photos. The more detail we have about the existing building, the more reliable the estimate.
- Fixed-fee quote. We confirm the fee and timeframe.
- Measure and price. We price new work, alterations and making good.
- Receive your estimate. A clear breakdown with assumptions and exclusions.
Related services
- New Build – Full Rate Estimate Cost: A detailed, measured estimate for a new home or development, priced at full market rates for labour, materials, plant and margin.
- Labour-Only Rate Estimate Cost: Estimates of labour-only costs for owner-supplied materials, labour-only contracts and trade package pricing.
- QS Verification Reports: An independent second look at your budget, builder's price and costs. Ideal when a lender wants verification, or when you want to be sure the numbers stack up.
This guide is general information only and does not replace advice on your specific project. Costs, building rules and lender or insurer requirements change and every project is different, so please speak to us about your own circumstances before acting.
Residential Additions & Renovations Estimates FAQs
Because part of the cost depends on the condition of the existing building, which cannot always be seen. We allow for that with clear assumptions and a sensible contingency.
Yes. We can price alternatives, such as different finishes or scope, so you can compare.
Yes. We can check it against the plans and tell you what looks missing or unusually high or low.
Yes. We prepare estimates for residential additions and renovations, including demolition, making good and connecting to the existing building.
Ready to talk about Residential Additions & Renovations Estimates?
Contact us today for a fixed-price quote. Independent, accurate and professional.