Construction cost calculator/estimator
New homes, renovations & extensions

Click on the image on the right to start the calculator.

• Note that our construction cost calculator only gives an estimate of building costs.
• It is only suitable for use before any detailed plans are made.
• To get more accurate results you will need to adjust the default per-square-metre costs to a value suitable for your area (labour and materials costs are highly variable).
• If you are looking for accurate residential construction costs, you will require detailed construction plans and the services of a quantity surveyor, licensed builder, or specialist home estimator.

Do you have an iPhone? Learn about Builders Buddy. We now sell a full-featured app version of our construction cost calculator ($1.99). It allows you to save your results, label them, and email them. Calculation parameters are fully customisable.

Cost assumptions

Cost assumptions built into by our construction cost calculator are as follows: (Note: They are easy to change!)

• Renovations, additions or extensions often cost twice as much, per square metre, as the construction of a new house or building (e.g. a detached granny flat). Please note: Some jobs will cost more than double, and a few jobs will cost the lucky owner less than double; it is best to speak to at least one builder or other construction professional to determine what the case will be for your job. You can then make adjustments to the calculator's settings to account for this.
• A custom designed house on an excellent site using basic finishes will have a base cost of $1500/square-metre. NOTE: If you are building a project home per-square-metre cost are significantly lower - use $900 - $1200.
• A custom designed house on an excellent site using standard finishes will cost an extra $300/square-metre ($1800 per square metre).
• A custom designed house on an excellent site using high-end or luxury items such as expensive bathroom or lighting fittings will cost at least $600 extra per square-metre ($2100 per square-metre).
• If the building site is "good", but not excellent, add 7% to the base cost of $1500 (eg. a slightly sloping block of land).
• If the building site is "difficult", add at least 20% to the base cost (eg. a steep block of land, or one that requires extra drainage).
• Outdoor areas such as decks, patios and verandahs cost on average $900/square metre. Use a higher value if the outdoor area will have a roof, or will be high of the ground.
• Garages cost an average of $1200 per square metre. Use a higher value if there are any complications such as a sloping block, poor drainage, etc.

Where you can find costing data

1. Specialised estimation businesses

The following 3 businesses all provides professional and affordable cost estimates for new homes and major renovations. All three companies can prepare cost estimates for projects anywhere in Australia.

• Denary Construction Estimating Services. NSW based. Ph: 02 4962 1505.
• Sidcorp Construction Estimating Service. NSW based. Ph. 0417 777 813.
• Home Estimators. Victoria based. Ph. 0438 187 885.

2. Licenced builders

Contact local home builders in our online directory, a builder you have used before or try one of our sponsors:

• If you are building or renovating in the greater Brisbane area contact Abode Construction and ask for Justin Andrews: 07 3188 3650.
• For Perth and all of Western Australia contact the ABN Group of building companies and request indicative per-square-metre costs of a new home with different levels of finishes.
• If you are building a new home or renovating on Sydney's North Shore, the Central Coast or the Hunter/Newcastle region, try these builders:

  Coastal Construction & Building Master Builder Les Smith

  A&M Flynn Building Gecko Homes

A final note: quoting on a new house or renovation is a time consuming process so please be considerate and only call in a builder to give you a detailed quotation when you are committed and ready to move forward.

Start calculating your construction costs >>

Questions?

We have a free service on our Facebook page. Practicing professionals will try their best to answer any relevant questions you may have.

Further reading

Renovating? Get a free Renovators Guide from Abode Construction's website.

Subscribe to our newsletter and receive our free eBook "Designing Your Own Home". Just click the button shown on the right.

Capital allowances for investment properties	Landscaping & gardening articles
How to keep construction costs down	Make Your Home Warm in Winter & Cool in Summer
Kitchen cost calculator	Bathroom cost calculator
Australian residential architecture styles	Becoming an owner builder
Council requirements and reports.	How to read plans
How to read a quote	Residential structures - the basics
Design tips	How to design your own home
Choosing a fence For your Home	Find a local builder

Sponsors

	Denary Construction Estimating Services. Denary utilises vast experience in the construction industry to provide detailed estimates using the latest computerised measuring and estimating technologies available. Ph: 02 4962 1505.
	Sidcorp Construction Estimators are a professional Australia wide service specialising in residential projects incluidng new homes and extensions. Contact Sidcorp today for more information about the estimating process.
	Home Estimator assists Owner Builders, Builders, Developers and Designers across Australia. Home Estimator estimations are prepared so you receive contains no hidden surprises. By considering the direct and indirect costs of building, Home Estimator ensure your estimate is comprehensive and reliable.
	Abode Construction are committed to quality and detail. Director Justin Andrews has over 20 years experience in the building industry and is a member of both the Housing Industry Association of Queensland and the Master Builders Association of Queensland.
	Angela Elliss, B.Sc. Architecture. Residential design specialist. New homes, renovations & additions. Central Coast, Sydney North Shore & Newcastle. Angela wrote this article and many others on this website. Ask Angela questions on the Home Design Directory Facebook page or see our frequently asked questions page.