Budget Calculator

The Archicentre Budget Calculator has been created to help you develop a budget for a new home or renovation project. A more accurate construction cost estimate can be calculated once a design has been prepared, but our Calculator will help you to decide whether to commission a design or re-think your requirements.
It’s easy to use. Simply enter the number of items you want to include in your project (e.g. 2 bedrooms, 1 kitchen upgrade, 4 window replacements). Then let the Calculator do the rest!
You’ll be presented with a budget range (e.g. $250,000-$300,000) that you can increase or decrease by adding or subtracting items until you’ve calculated a budget you’re comfortable with.
Once this is done, consider a Design feasibility service. This will provide you with sketches and a detailed construction cost estimate that will enable you to tackle your project with confidence.

New Construction
Demolition required?
(Whole or partial. Calculation is based on an average 100sqm)
Bedrooms (Number of bedrooms)
Bathrooms (Number of bathrooms)
Walk-in Wardrobes (Number of WIRs)
Built-in Wardrobes (Number of BIRs)
Living/Family Rooms (Number of rooms)
Dining Room (Number of rooms)
Study (Number of studies)
Stairs (including void) (Number of stairs)
Home Theatre (Number of home theatres)
Kitchen (Number of kitchens)
Laundry (Number of laundries)
Single Garage (Number of garages)
Multi Garage (Number of garages)
Car Ports
Single Car Port(Number of car ports)
Multi Car Port(Number of car ports)
Unroofed(Number of decks)
With Pergola (UCA)(Number of decks)
Extended Eaves (UCA)(Number of decks)
Kitchen Upgrade (Number of kitchens)
Bathroom/Ensuite Upgrade (Number of bathrooms/ensuites)
Laundry Upgrade (Number of laundries)
Roof framing required?
(Calculation is based on an average size of 30sqm)
Attic conversion for storage?
(Calculation is based on an average size of 10sqm)
Attic conversion for habitation?
(Calculation is based on an average size of 30sqm)
Re-stumping required?
(Calculation is based on an average 150sqm house)
Re-wiring required?
(Calculation is based on an average 150sqm house)
Re-roofing required?
(Calculation is based on an average 150sqm house)
Re-plumbing required?
(Calculation is based on an average 150sqm house)
Window replacement (Number of windows)


  1. Location plays a big part in building cost with inner-suburban and regional projects often commanding prices well above average. Caution should be exercised when developing budgets for projects in these areas.
  2. Costs are based on average room sizes and medium standard fittings, fixtures and finishes.
  3. Costs are based on ground level construction assuming reasonable access and generally flat site. Add 20-25% for first floor construction and additional costs for sloping sites and smaller extensions.
  4. Costs include allowance for the following:
    • Reasonable circulation space.
    • Builders Preliminaries.
    • External services at 5% of new building works (assumed zero for alterations).
    • Goods & services tax at 10% of construction cost.
  5. Costs exclude allowance for the following:
    • Cost escalation.
    • Contract contingency.
    • Professional fees.
    • Loose furniture & equipment.
    • Costs associated with contaminated soil, removal of hazardous materials, bushfire-resistant construction or similar.
    • Sundry items such as water tanks, solar panels, electrical/white goods, skylights, termite management, landscaping, sheds/workshops, paving etc.
    • Home improvement works (e.g. miscellaneous repairs, carpet removal and floor polishing, external rendering, re-painting, ceiling insulation etc).