Plankley

How to plan a DIY project, from first measurements to the final order

By the Plankley team · Last checked

Most ordering mistakes happen before anyone picks up a tape measure: the job isn't pinned down, a layer gets forgotten, or the delivery can't reach the back garden. Work through the steps below in order, and you'll end up with a materials list you can trust, a plan for getting it on site and a clear idea of which parts need a professional.

Pin down the job

Write one or two sentences saying what will exist when you've finished: "a 4 × 3 m slab patio laid to a fall away from the house", not "do the garden". Then list what's included and what isn't. Anything you're unsure about, such as moving a drain or a socket, goes on a separate list to ask about before you order anything.

Measure everything, and write it down

Sketch the area from above and mark every measurement on the sketch. Split awkward shapes into rectangles and triangles, measure each one, and note anything that comes out, such as doors, windows or a manhole cover. Measure twice, in metres or millimetres, and keep the sketch: you'll need it again when you check the delivery.

Our guides to measuring a room for flooring and measuring a concrete slab show the method for two common jobs.

Work through the layers

Most jobs are more than one material. A patio, for example, is a dig, a sub-base, a bedding layer, the slabs and the jointing. List each layer from the bottom up, then work out each one with its own calculator. Each calculator shows its sum and the figures it starts from, and you can change any of them to match the product you're buying.

If the job is one of our project estimators, such as a shed base or a patio, it runs the calculators in order and gives you one shopping list.

Check the allowances

Every quantity needs an allowance for cuts, breakage and settling, and the right one depends on the material and the job. Each calculator shows the allowance it uses, and you can change it. Round countable things up to whole packs, bags or lengths: a part-pack can't be bought.

Check permissions and what's underground

Before you commit to a design, check whether it needs planning permission or building regulations approval where you live. The rules differ between England, Wales, Scotland and Northern Ireland, so check your own council's or nation's guidance. If you're digging, find out where buried pipes and cables run before you start.

Some work has to be done or signed off by a registered professional: most electrical work, and any work on gas appliances or pipework. Every electrics and gas calculator on this site says so, with a link to the official register.

Plan deliveries, storage and waste

Think about how materials will reach the spot where you need them: the width of the side gate, whether a lorry can unload on the road, and how far heavy bags will be barrowed. Decide where they'll sit until you use them and how you'll keep cement, plaster and timber dry. Work out what will come out, too: the muck away calculator turns a dig into skips, allowing for soil bulking up once it's dug.

Put the work in order

List the stages in the order they happen, and note anything that has to dry, cure or settle before the next stage. That tells you when each delivery is needed, so materials don't sit in the rain for weeks.

Check the list before you order

Go back to the sketch and check every layer has a line on the list, every figure matches the product you're actually buying, and every quantity is rounded up to whole packs. Check the pack sizes and coverage on the supplier's page against the figures you used: if they differ, change the figure in the calculator and run it again.

Before-you-start checklist