Home Renovation Budget

Free Home Renovation Budget calculator with clear step-by-step results.

About Home Renovation Budget

Builds a renovation budget from a rate per square metre set by specification level, adds structural work as a separate lump sum, then layers professional fees and contingency on top - in that order, because fees are a percentage of construction and contingency has to cover both.

Formulas

Construction cost

Cost = area x rate for the specification level + structural work

Total budget

Total = construction x (1 + fee rate) x (1 + contingency)

Worked example

With the default values below, Home Renovation Budget returns Total renovation budget of $108,790.00. Change any input above and every figure here is recalculated in your browser.

Inputs used

Area being renovatedminimum 0.5 m2: 65 m2
Specification levelone of Basic refresh, Mid specification, High specification, Premium: Mid specification
Structural alterationsminimum 0 $: 8,000 $
Design and professional feesaccepts 0–30 %: 10 %
Contingencyaccepts 0–50 %: 15 %

Results

Total renovation budget: $108,790.00
Construction cost: $86,000.00
Design and professional fees: $8,600.00
All-in cost per square metre: $1,673.69

Step by step

1Values used
2Construction cost
3Total budget
4Total renovation budget= $108,790.00
5Construction cost= $86,000.00
6Design and professional fees= $8,600.00
7All-in cost per square metre= $1,673.69/m2

Assumptions and limits

The result is derived only from the 5 inputs listed above. Anything not among them is not part of the calculation.
In particular, this calculator does not take inflation or compounding frequency into account.
Figures are rounded for display to 2 decimal places, so totals built from several rounded parts can differ slightly from the unrounded arithmetic.
Indicative budgeting only. Renovation work may require planning permission, building control approval and party wall agreements, and costs vary widely with condition, access and location.

How these calculators are built and tested is described on the Methodology page. If a figure looks wrong, please report it.

Indicative budgeting only. Renovation work may require planning permission, building control approval and party wall agreements, and costs vary widely with condition, access and location.

Frequently Asked Questions

Why is contingency applied after fees?

Because overruns generate extra design and supervision time too. Applying contingency to the combined figure covers both consequences of a change.

Are the rates per square metre realistic?

They are order-of-magnitude planning figures and vary by two or three times between regions and between a cosmetic refresh and a full strip-out. Replace them with local quotes as soon as you have them.