About BuildBatch
Measure once, get the complete batch to buy. BuildBatch turns one room's measurements into a checkable buying list in the packs you can actually buy, and shows you the arithmetic that got there.
Who it is for
Anyone standing in a room with a tape measure, wondering how much to buy.
- Homeowners and DIY. No trade knowledge assumed. Every number the calculator uses is on screen, in plain words, and you can change any of it.
- Tradespeople. A quick second opinion and a list you can copy into a quote or send to a merchant. It is not a substitute for your own judgement about the surface.
It is built for UK practice: metres, litres, and the tin and pack sizes sold here.
How it works
- Whole packs, not just totals. A total in litres is not a shopping list. Quantities are rounded up to real tin sizes, the combination of sizes that costs least or leaves least over is worked out from the sizes and prices you give, and you are told what will be left over.
- The whole job, honestly. A room refresh lists the paint, wallpaper, tiles or flooring and everything around them: preparation, consumables, tools, trims. Where a quantity depends on the surface or the product, it says “check first” and what decides it, rather than inventing a number.
- Every assumption is visible and yours to change. Coats, coverage, wastage allowance and tin size all start at an example value, clearly labelled as an example, and sit beside the answer.
- The working is shown. Each answer comes with the sum that produced it, so you can check it or hand it to somebody who will.
- Nothing to sign up for. No account is needed and no email address is asked for, and nothing is stored unless you save a project. See privacy.
How the estimates are worked out covers where the numbers come from and how they are checked.
What it does not do
Being clear about this matters more than sounding capable.
- It does not survey your room. It works from the measurements you type in, and it cannot see damp, bare plaster, a difficult colour change or a surface that needs a different product.
- It does not give professional advice. For anything structural, hazardous or regulated, ask somebody qualified.
- It does not quote prices of its own. A price in a batch is one you typed, or one recorded against a reviewed, published product with the date it was checked. There is no shop, and there are no affiliate links today; if a merchant link ever appears beside a reviewed offer it is labelled before you click.
- It does not guarantee you will buy the right amount. It is an estimate, and it says so on every result.
Where this has got to
BuildBatch is a working prototype, release 0.14.0. The room refresh planner covers paint, wallpaper, tiles, flooring, and new skirting and architrave, for one room measured once. The room planner draws a room of any shape to scale, as long as its walls are straight. The paint calculator is ready for review; a flooring calculator is being built and is not on the site yet.
The arithmetic passes its own automated tests, and before a release is published those tests are run again on a clean copy of it. Several releases and parts of the work have also been checked by AI tools other than the one that wrote the code, which tried to break it. Those are checks by software, not reviews by people. Three things have not happened yet: no person outside the build has reviewed the code, a qualified painter or decorator has not checked the assumptions, and nobody who was not involved in building it has been watched using it. Until they have, treat every answer as a starting point and check it against the tin or the pack.
Pages are drafted with AI tools, and Angelos Hallaci is responsible for what is published. A page that compares products follows its own rules, set out on the page “How we compare products”: a second AI tool checks its figures against the makers' published pages, and no person has checked such a page yet.
Every page carries a prototype notice.
Who runs it
BuildBatch is run by Angelos Hallaci, as an individual. It is not run by a company. If that changes, this page will say so.
To contact BuildBatch, email contact@buildbatch.co.uk.
To tell us something is wrong, see report a problem.
How it is paid for
At the moment, it isn't: nothing on this site earns money, and nothing is for sale.
The intention is that links to merchants may earn a commission later. If that ever happens, the link will say so where you can see it before you click, the commission will not change what the calculator tells you, and this page will be updated before the first such link appears. There are none today.