Comprehensive Guide: How to Perform a Construction Takeoff

A construction takeoff is the process of measuring and counting everything needed to build a project, straight from the plans: concrete, steel, timber, plasterboard, tiles, doors, light fittings and the labour to put them together. It's the first step in every estimate.

If you're a homeowner, here's why you should care: a builder's quote is only as good as their takeoff. Miss a few square metres of tiling or a run of guttering and either the builder wears it, or you do through a variation.

Why this matters to you as a homeowner

When you're comparing quotes, you're really comparing takeoffs. Two quotes can differ by tens of thousands of dollars simply because one builder measured more carefully, or left more items as allowances.

Ask each builder:

How did you measure the job? From the full set of plans and specifications, or from a standard house design?
What's in the provisional sums (PS) and prime cost (PC) allowances? These are estimates, not fixed prices, and they can grow. A quote heavy in allowances may look cheaper than it really is.
What isn't included? Site costs, driveway, landscaping, fencing and connections are common exclusions.

Then compare quotes line by line, not just on the bottom line. Our C4 Asking the Right Questions checklist helps with what to ask.

Manual vs digital takeoffs

There are two ways to do a takeoff. Both produce the same thing: quantities of materials and labour that are priced to create the estimate.

Manual takeoffs

The traditional way: paper plans, a scale ruler, highlighters, a calculator and a notepad.

Good for: small jobs, renovations, or when only paper plans are available.
Downsides: slow, and easy to make mistakes, such as reading the wrong scale, double-counting or missing items. Re-measuring after a plan revision means starting again.

Digital takeoffs

You load PDF or CAD plans into takeoff software and measure on screen. The software calculates areas, lengths and counts as you click, and builds the quantity list as you go.

Good for: most residential and commercial work, especially jobs with many revisions.
Downsides: software costs and a learning curve. You still need to understand construction to know what to measure. Software doesn't fix a bad assumption.

Options used in Australia include Cubit (by Buildsoft), ConX and Autodesk Takeoff, among others. (None of these are sponsors. I mention ConX because it is affordable and easy to use.) Most offer free trials, so test a few on a real job before committing.

Step by step: doing a takeoff

The steps are the same whether you're using a ruler or a mouse.

1. Gather the documents

You need the complete, current set of plans: architectural drawings, engineering (slab, frame, tie-downs), the specification, the soil report and any energy rating or BAL requirements. Check the revision numbers. Measuring an old revision is one of the most common and costly mistakes.

2. Check the scale

Confirm the scale on every sheet. On PDFs, calibrate against a known dimension, as printed and scanned plans are often slightly off.

3. Work through the job in a set order

Use a consistent sequence so nothing is missed. Following the build sequence works well:

Site works and earthworks
Slab or footings: concrete, reinforcement, membrane, termite management
Frame: walls, roof trusses, bracing, tie-downs
Roof: sheeting or tiles, sarking, gutters, fascia, downpipes
External walls: brick, cladding, wrap, windows and doors
Services: plumbing, drainage, electrical, hot water
Internal linings: insulation, plasterboard, cornice
Fit-off: cabinetry, doors, hardware, tiling, waterproofing, painting
External works: driveway, paths, fencing, landscaping

4. Measure in the right units

Use Australian metric units throughout:

Areas in square metres (m²): slab, roofing, plasterboard, tiling, painting
Lengths in lineal metres (lm): timber framing, gutters, skirting, cornice
Volumes in cubic metres (m³): concrete, excavation, fill
Counts as numbers: doors, windows, power points, light fittings, taps

5. Add waste and extras

Allow for offcuts, breakage and laps. Waste factors vary by material and layout: tiling with lots of cuts needs more than a big plain floor. Don't forget items that aren't drawn but are needed, like fixings, sealants, scaffolding, skip bins and temporary fencing.

6. Estimate labour

Work out the labour for each trade, either as hours at an hourly rate or as a rate per m² or per item from your subcontractors.

7. Price it and compile the estimate

Apply current supplier and subcontractor prices to each quantity, add preliminaries (site establishment, insurances, supervision, QBCC home warranty insurance and approvals), then margin and GST.

8. Check it

Have someone else review it, or compare it against similar past jobs per m². If the number looks wrong, it probably is.

The bill of quantities

On larger projects, the takeoff is often formalised into a bill of quantities (BoQ): a document listing every item of work with its description and quantity, usually prepared by a quantity surveyor. Builders price the BoQ when tendering, so every tenderer is pricing the same quantities. The BoQ is also used to value progress claims and variations.

Most project home quotes aren't based on a formal BoQ, but the same principle applies: the more detailed the breakdown, the easier it is to compare quotes and spot gaps.

The Australian Standard Method of Measurement

In Australia, quantity surveyors measure to the Australian Standard Method of Measurement of Building Works (ASMM), published by the Australian Institute of Quantity Surveyors (AIQS). It sets out how each item is measured and described so everyone pricing a BoQ is working from the same rules. That consistency reduces disputes over what was or wasn't included.

Common takeoff mistakes

measuring from an out-of-date revision
wrong scale on a PDF or a reduced print
missing items that aren't drawn, like fixings, flashings or temporary works
forgetting waste factors
double-counting where trades overlap
copying quantities from a "similar" job without checking

The bottom line

For builders, a careful takeoff is the difference between profit and loss on a job. For homeowners, it's the difference between a quote you can rely on and one that grows through variations. When you're comparing quotes, ask how the builder measured the job, and read the allowances as closely as the price.

A Step by Step Guide: How to Do a Construction Takeoff

Why this matters to you as a homeowner