What is considered fully enclosed floor area?

This includes generally enclosed floor space as well as areas such as: staircases, garages, attics, basements, lift shafts

What is considered unenclosed floor area?

Balconies, verandahs, porches and patios walkway

Duo Tax: Free Construction Cost Calculator

Duo Tax offers a comprehensive construction costs calculator to help with gauging cost information so you can decide if the cost to build suits your budget.

Use Calculator

Affiliate members of the Australian
Institute of Quantity Surveyors

An accurate estimation of building costs and construction costs is integral to controlling and monitoring budgets for construction projects.

Given that every new house has a different style, size, floor area, fittings, finish and other factors, it’s ideal to use our construction costs calculator to determine the average building costs and construction costs.

Frequently Asked Questions

How do I calculate the floor area?

Our construction costs calculator is based on gross floor area. The gross floor area refers to the total floor area that’s fully enclosed across all floor levels. This should be measured based on the external measurement of the building to account for the thickness of the walls.

What is considered a fully enclosed floor area (gross floor area)?

This includes generally covered areas of floor space, such as:

Staircases
Garages
Attics
Basements
Lift shafts

What is considered an unenclosed floor area?

This includes generally uncovered areas of floor space, such as:

Balconies
Verandahs
Porches and patios
Walkways

How accurate is your construction cost calculator?

While every effort is made to ensure data and information are up to date, the calculators are for indicative purposes only and should not be used for any purpose other than an estimation of the average cost. If you’d like an accurate estimation, get in touch with the Duo Tax team for a free estimate from a quantity surveyor.

Who can provide an accurate estimation of the building costs and construction costs?

Quantity surveyors are qualified to provide cost reports and accurate estimations once detailed plans and data have been submitted. The cost calculator is designed to provide you with an estimate based on the information provided.

Can you provide cost estimates and cost reports?

Yes, we can. We can work closely with architectural drawings to prepare elemental cost plans as well as detailed cost plans with consideration for budget and value. If you’re a home builder, we can provide effective cost planning to achieve realistic estimates. The other benefit is that our quantity surveyors can constantly monitor your project and will help identify overspending on your budget at an early stage to be able to take prompt action.

Construction Estimations