A takeoff is only as good as the measurements behind it. Most estimating errors come from the site visit, not the maths.
Bring the right kit
- A 8 m tape and a 30 m tape or measuring wheel
- A laser distance meter for rooms and heights
- A level and an angle finder for pitches and falls
- A phone for photos of every elevation, junction and problem area
- Squared paper or a sketch app
Sketch first, then measure
Draw a rough plan before you measure anything. Then measure in a consistent direction, clockwise around a room or left to right along an elevation, writing each dimension on the sketch as you go. This is how you avoid missing a wall or measuring one twice.
Break shapes down
Split complex areas into rectangles, triangles and circles. Label each one (A, B, C) and keep the sub-areas. If one dimension turns out to be wrong later, you only need to fix one piece.
Measure what you'll build, not what's there
A patio quote needs the finished size, including edging. A floor quote needs the area to the walls, not around furniture. A fence quote needs the line, gates and level changes. Think about the finished job while you measure.
Check square
Measure both diagonals of rectangular areas. If they differ, the space isn't square, and that affects tile layouts, flooring waste and framing. The diagonal calculator tells you what they should be.
Note the things that cost money
- Access: can a lorry get close? Is there a pump route?
- Levels and falls
- What needs removing first
- Services in the way
- Where materials and waste will go
Back at the van, enter the numbers into the calculators while they're fresh, add them to a job, and the quote is half written.
This guide is general information for estimating. It is not engineering, legal or tax advice. Check the Building Regulations and Building Control for your project.