# BuildBatch

> A free UK job planner for paint, wallpaper, tiles, flooring, carpet, skirting, plasterboard and loft insulation, with sheet vinyl, woodwork paint, a concrete slab, a patio, and sub-base and gravel: measure once and get the whole shopping list in real tin, roll, box, pack, bag and length sizes, with the preparation, tools and checks, a reason on every line and the working for every quantity. Rooms of any shape with straight walls can be drawn to scale. No account is needed and everything is worked out in the browser; an optional account keeps saved projects on every device.

Facts BuildBatch uses and states:

- BuildBatch is a free UK job planner. An estimate is arithmetic on the measurements and product figures the user enters; the product's own instructions decide coverage, coats and preparation.
- Paint: 12 m² a litre, two coats and 10% spare. The 12 m² a litre is the lower middle of 18 makers' figures for the 103 emulsions read for BuildBatch's catalogue from 29 September to 12 October 2026 (the catalogue lists the published ones: 99 emulsions from 16 makers, in /llms-full.txt): a typical figure, not any one paint's (https://buildbatch.co.uk/sources/).
- Built with AI tools; not yet checked by a tradesperson.
- Typical figures found by research are labelled typical and name where they were read (a maker's or a supplier's page, or a trade calculator's or guide's page where neither publishes one) and the day, and are never a product's own; where the published figures differ, a typical figure may be the middle of two or more of them, and the line names each (wall and ceiling paint at 12 m² per litre in two coats, the lower middle of the makers' own figures in BuildBatch's catalogue, with a mist coat of white contract matt on new plaster; tile adhesive from makers' data sheets and grout by Norcros Adhesives' rule, woodwork paint between two makers' "up to" figures, decorator's caulk, masking tape, dust sheets and lining paper, wallpaper paste, skirting in the stock length that leaves the fewest joins, underlay, scotia beading and carpet gripper, plasterboard screws, tape and finish plaster, a patio's bed with its dry materials, the sub-base's bags at a compacted depth, packs and jointing, concrete mixes from Tarmac, loft rolls by thickness).
- Labour rates are other sites' published figures with their dates, never BuildBatch's and never a quote.
- Example figures are labelled as examples (paint: 10% extra; wallpaper: rolls 53 cm × 10.05 m, and a paper whose match is not given is counted as a straight match with a 64 cm repeat and says so; flooring: 10% extra for cuts; architrave in 2.1 m lengths; wall tiles: a 1 m² box, 10% extra for a straight lay; plasterboard: boards 1.2 m × 2.4 m, one layer, 10% extra; a slab 100 mm thick; wall adhesive: two boards per bag).
- What has to be in place before a job starts and is not a thing to buy is said before the list, and a line that waits on the person's own job carries the one question to ask.
- Wallpaper is counted in whole drops: height plus 10 cm, rounded up to the pattern repeat, with doors and windows not taken off.
- Skirting and architrave are counted in whole lengths from a cutting plan: one piece per wall with each door's width off the run, two legs and a head per door.
- Tiled walls are the perimeter, or the length of only some walls, times the tiled height, less the doors (nothing is taken off some walls only); windows come off only when tiled to the ceiling, and their reveals are then added; the wall above half-height tiles is painted on its own line.
- A slab's concrete comes as bags, mixed on site or ready-mixed by its volume when no way is chosen, a rule of BuildBatch's own that the list says is its own.
- Plasterboard is counted from the selected surface area times the number of layers, with the extra for cuts added, divided by the board area and rounded up to whole boards. This is not a cutting layout; board type, framing, fixings and centres must come from a complete system specification.
- A price on a list is a partner shop's own, read from the file that shop publishes, with its day and the shop's link marked Ad; a list may show its total at each partner shop that prices it, side by side, each with its day, never ranked; a material no shop prices may show a typical price range, from at least two named publishers, read on a stated day, labelled typical, with whether VAT is stated; a job's cost is given three ways: materials, having it done (published labour figures, worked for the room's own area where the publisher gives a rate per square metre), and the two together, which are published figures and arithmetic, not a quote. BuildBatch does not survey rooms, rank shops, or call any product or price the cheapest.

## Quick answers

- [How much paint for a room? Table by room size (UK)](https://buildbatch.co.uk/examples/how-much-paint-by-room-size/): A 3 × 4 m room (9.8 × 13.1 ft), 2.4 m high, with one door and one window, needs 5.7 L of wall paint and 2.2 L of ceiling paint for 2 coats at 12 m² per litre with 10% extra: 1 × 5 L tin + 1 × 2.5 L tin (7.5 L) for the walls and 1 × 2.5 L tin (2.5 L) for the ceiling. Typical figures.
- [How many rolls of wallpaper? Table by room size (UK)](https://buildbatch.co.uk/examples/how-many-rolls-of-wallpaper-by-room-size/): A 3 × 4 m room (9.8 × 13.1 ft), 2.4 m high, needs 10 rolls of wallpaper while the paper’s match is not known: the planner then counts a straight match with a 64 cm repeat, so the rolls do not run short, which is 28 drops of 2.56 m, 3 from each 53 cm × 10.05 m roll, leaving 2 spare drops. Example figures.
- [How many packs of laminate? Table by room size (UK)](https://buildbatch.co.uk/examples/how-many-packs-of-laminate-by-room-size/): A 3 × 4 m room (9.8 × 13.1 ft) has 12 m² of floor and needs 13.2 m² of laminate with 10% extra for cuts: 7 packs of 2 m² (14 m²), with 0.8 m² left over. Example figures.
- [How many tiles for a bathroom? Table by room size (UK)](https://buildbatch.co.uk/examples/how-many-wall-tiles-for-a-bathroom-by-room-size/): A 2 × 2.5 m bathroom (6.6 × 8.2 ft), 2.4 m high, with one door, has 20.09 m² of wall, tiled to the ceiling, and needs 22.1 m² of tile with 10% extra for cuts: 23 boxes of 1 m² (23 m²), with 0.9 m² left over. Example figures.
- [Is paint coverage per coat? Yes: what m² per litre means](https://buildbatch.co.uk/guides/paint-coverage-explained/): Yes: the coverage on a tin is per coat, so a second coat takes as much paint as the first and two coats need twice the litres.
- [How long between coats of paint? 10 emulsions: 1 to 4 hours](https://buildbatch.co.uk/guides/how-long-between-coats-of-paint/): Ten matt emulsions' makers say 1 to 4 hours between coats: Crown Trade Matt Vinyl 4 hours, Dulux Matt 2 to 4, Farrow & Ball Estate Emulsion 2.
- [Mist coat ratio, drying time and how many coats](https://buildbatch.co.uk/guides/mist-coat-ratio/): Thin the emulsion as its own tin says: Dulux says 10 parts paint to 1 part water, Valspar 3 parts to 1, and Crown Trade's Matt Vinyl 40% water.
- [Cost to paint a room](https://buildbatch.co.uk/costs/painting-a-room/): Painting the walls and ceiling of a 4 × 3 m room comes to £344 to £1,075 of labour at published rates (43.01 m²).

## Tools

- [Work out what you need](https://buildbatch.co.uk/): measure once; paint (walls, ceiling and woodwork), wallpaper, wall or floor tiles, a new floor, a carpet or sheet vinyl, plasterboard, loft insulation, a concrete slab, a patio, or sub-base and gravel (MOT Type 1, gravel or both), several room jobs on one list, and new skirting and architrave; every line the job needs in real packs, marked Need, Check first, Already have or Not needed.
- [Room planner](https://buildbatch.co.uk/room-planner/): draw a room to scale (L-shapes, alcoves, chimney breasts, angled walls); floor area, perimeter and a dimensioned drawing to print at 1:50 or 1:100.
- [Wallpaper calculator](https://buildbatch.co.uk/wallpaper-calculator/): Rolls for a room, from the pattern repeat.
- [Tile calculator](https://buildbatch.co.uk/tile-calculator/): Tiles, adhesive and grout, walls or floor.
- [Skirting board calculator](https://buildbatch.co.uk/skirting-board-calculator/): Whole lengths, cut wall by wall.
- [Plasterboard calculator](https://buildbatch.co.uk/plasterboard-calculator/): Boards, screws and tape, walls or ceiling.
- [Laminate flooring calculator](https://buildbatch.co.uk/flooring-calculator/): Packs, underlay and trims for a new floor.
- [Carpet calculator](https://buildbatch.co.uk/carpet-calculator/): Carpet off the roll, underlay and gripper.
- [Sheet vinyl calculator](https://buildbatch.co.uk/vinyl-flooring-calculator/): Sheet vinyl off a 2, 3 or 4 m roll.
- [Loft insulation calculator](https://buildbatch.co.uk/loft-insulation-calculator/): Mineral-wool rolls for a cold loft floor.
- [Concrete calculator](https://buildbatch.co.uk/concrete-calculator/): Bags, a site mix or ready-mix, for a slab.
- [Patio calculator](https://buildbatch.co.uk/patio-calculator/): Slabs, sand, cement and sub-base.
- [MOT Type 1 calculator](https://buildbatch.co.uk/mot-type-1-calculator/): Type 1 sub-base in bags, and its weight.
- [Gravel calculator](https://buildbatch.co.uk/gravel-calculator/): Gravel or chippings in bags, and the weight.
- [Paint calculator](https://buildbatch.co.uk/paint-calculator/): litres and whole tins for walls and ceilings.
- [All calculators](https://buildbatch.co.uk/calculators/): every tool on one page.
- [Cost to paint, tile or lay a floor](https://buildbatch.co.uk/labour-costs/): what UK cost guides publish that tradespeople charge, each with its publisher and date; never BuildBatch's figure and never a quote.
- [Check a quote](https://buildbatch.co.uk/quote-check/): where a quote sits against those published rates, for the job and the size entered; no verdict.
- [Labour rates as JSON](https://buildbatch.co.uk/labour-rates.json): the same published rates, with their sources and dates, as one file.

## Interface for assistants

- [Question script](https://buildbatch.co.uk/ask.json): what to ask a person before planning their room, as JSON.
- [Planner](https://buildbatch.co.uk/plan.json): the shopping list for one room as JSON, from a query string; a call with no job answers 400 and says what to ask.
- [OpenAPI description](https://buildbatch.co.uk/openapi.json): both of the above, with examples.
- [MCP endpoint](https://buildbatch.co.uk/mcp): four tools for an MCP client, over streamable HTTP, no key: quick_room_list (one room's list from a job and three measurements, or a typical room), plan_room (every option), find_guide (the guides' own short answers) and ask_questions.
- [Use BuildBatch in your AI assistant](https://buildbatch.co.uk/assistants/): for a person, how to connect Claude, ChatGPT, Claude Code, VS Code or Cursor to it.
- [Links that open a room](https://buildbatch.co.uk/links/): the same parameters as a link a person can open and check.
- [Catalogue of these interfaces](https://buildbatch.co.uk/.well-known/api-catalog): the same addresses as a set of links (RFC 9727), for a program that looks there first.
- [Signing in](https://buildbatch.co.uk/auth.md): no account, key or token is needed for any of it; a person may make an account of their own to keep projects on several devices, and an agent never makes one for them.

## Every page as Markdown

Each page listed here is also served as Markdown, without its markup or scripts: put /md in front of its path and index.md after it. https://buildbatch.co.uk/guides/how-much-paint-do-i-need/ is at `https://buildbatch.co.uk/md/guides/how-much-paint-do-i-need/index.md`, and this site's home page at `https://buildbatch.co.uk/md/index.md`. Each page names its copy in a link of type text/markdown.

## For AI assistants: the loop

BuildBatch has an interface for assistants: free, read-only, no key, no account. Its description (OpenAPI) is https://buildbatch.co.uk/openapi.json. An MCP client can instead connect to https://buildbatch.co.uk/mcp: quick_room_list gives one room's list from a job and three measurements (or a typical room, said to be typical) as a short answer to show the person, plan_room takes every option, find_guide returns the guides' own short answers, and ask_questions the question script. A person connects it as https://buildbatch.co.uk/assistants/ says. Unlike the planner, which works in the person's browser, these work the list out on BuildBatch's server from the parameters sent: BuildBatch stores none of them, and counts only which tool, which job and which kind of caller.

1. Ask. GET https://buildbatch.co.uk/ask.json is the question script: what to ask the person, the allowed answers, which are required, when to ask, and the rules. Ask only for what is missing. Use only measurements the person gave you, never a guess.
2. Call. GET https://buildbatch.co.uk/plan.json with their answers as a query string. The parameters are the link recipe's below (v=1&job=...&length=...), and a job is required. One room a call. It returns the whole shopping list as JSON.
3. Show. Give the person the room summary, anything in summary.first (to have in place before starting: not things to buy), the lines with status need (what to buy) and then the lines with status check (decide these first), and listUrl, which opens the whole list with the working behind every quantity. Ask the person each question in summary.toAnswer: the answer changes the list. It is free and needs no account.
4. Say whose figures are whose. Unless you sent a product's own figures, the paint is counted at BuildBatch's typical figures, found from makers' own, and the roll, pack, box and allowance figures are its labelled examples; each line says which; BuildBatch was built and checked with AI tools and nobody outside the build has reviewed it; an answer has no prices, and its shop links only open each shop's own search. Tell the person to check the figures and follow each product's own instructions. The answer's honesty block has the words.

An example turn:

- The person says: "What do I need to paint my bedroom? It is 4.2 m by 3.6 m and 2.4 m high, with one standard internal door and a window 1.2 m wide and 1.1 m high."
- You call: GET https://buildbatch.co.uk/plan.json?v=1&job=paint&length=4.2&width=3.6&height=2.4&door=int-762&window=1.2x1.1
- You say: "For that room (4.2 m × 3.6 m, 2.4 m high; 1 door, 1 window) the list has wall paint, 1 × 5 L tin + 1 × 2.5 L tin (7.5 L); ceiling paint, 1 × 5 L tin (5 L); and then the preparation, tools and safety items. The whole list, with the working behind each quantity, is here and is free: https://buildbatch.co.uk/list/#v=1&job=paint&walls=paint&ceiling=paint&trim=none&units=m&length=4.2&width=3.6&height=2.4&door=0.762x1.981&window=1.2x1.1&surface=sound&subfloor=unsure&ground=unsure&fitting=unsure&end=15 The paint figures are BuildBatch's typical figures, not any product's (2 coats, 12 m² per litre, 10% allowance), so check them against the tin and follow its instructions. It was built and checked with AI tools, and nobody outside the build has reviewed it. This answer has no prices."

If a call answers 400, problems[] names the parameters to add or correct and ask[] the question ids in /ask.json to put to the person. Do not guess a missing measurement and do not send the same address again.

## Links that open a room

A link can open the planner with a room's measurements filled in: `https://buildbatch.co.uk/start/#v=1&job=paint&length=4.2&width=3.6&height=2.4&door=int-762`. The planner opens with every figure in a field the person can see and change, and the answer under them. Full explanation: https://buildbatch.co.uk/links/.

- Everything goes after "#", as key=value pairs joined with "&". v=1 is required and comes first; keys the planner does not know are ignored; anything missing, the planner asks for.
- job: paint, wallpaper, tiles (wall tiles), flooring, carpet, loft (loft insulation), both (paint and flooring), paint-carpet (paint and carpet), skirting (skirting and architrave) or plasterboard.
- units: m (default), cm, mm or ft. length, width and height are in those units; in feet write 13ft9in, or 13 for whole feet.
- door, window, opening: one key per opening, repeated for more. A typical size by name (int-762 standard internal door, int-686 narrow internal door, door-838 front door, win-standard window, win-small window, patio-1800 patio doors; the full list is on the links page) or width x height in the same units (1200x1100). Add *2 for two the same.
- trim: skirting, architrave or skirting,architrave, with any job. plan: the corners of a room that is not a rectangle, in metres, as x,y pairs separated by ";".
- Only use measurements the person gave you. Leave out any you do not have: the planner asks for them. Tell the person to check the figures when the page opens.

- A decorator who measured in millimetres: Painting the walls and ceiling of a room 4200 by 3600 mm, 2400 mm high, with a standard internal door and a window 1200 mm wide and 1100 mm high. `https://buildbatch.co.uk/start/#v=1&job=paint&units=mm&length=4200&width=3600&height=2400&door=int-762&window=1200x1100`
- A forum post about tiling a bathroom: Wall tiles up to 1.2 m in a bathroom 250 by 180 cm, 240 cm high, with a narrow internal door. `https://buildbatch.co.uk/start/#v=1&job=tiles&units=cm&length=250&width=180&height=240&door=int-686&walltiles=quick&walltiles.height=1.2`
- An AI assistant answering "what do I need to paint this room and lay a laminate floor?": Paint and a laminate floor for a room 4.2 by 3.6 m, 2.4 m high, with one standard internal door and one standard window. `https://buildbatch.co.uk/start/#v=1&job=both&length=4.2&width=3.6&height=2.4&door=int-762&window=win-standard&floor=quick&floor.covering=laminate`
- Someone measuring in feet and inches: New skirting and architrave for a room 13 ft 9 in by 11 ft 10 in with two standard internal doors. `https://buildbatch.co.uk/start/#v=1&job=skirting&trim=skirting,architrave&units=ft&length=13ft9in&width=11ft10in&door=int-762*2`

## Guides, examples, costs and products

- [All guides](https://buildbatch.co.uk/guides/): every guide, grouped by job, each with the question it answers.
- [Example shopping lists and tables by room size](https://buildbatch.co.uk/examples/): every worked shopping list and every table of what a room needs by its size, on one page.
- [UK labour costs](https://buildbatch.co.uk/labour-costs/): the cost page of each job, with what UK cost guides publish that tradespeople charge, each with its publisher and date; never a quote.
- [All products](https://buildbatch.co.uk/products/): the published products by kind and by maker, each with the coverage, the coats where given and the tin or bag sizes its maker states.
- Every page of each list, with its one-line answer, is in [llms-full.txt](https://buildbatch.co.uk/llms-full.txt).

## About

- [How the estimates are worked out](https://buildbatch.co.uk/how-estimates-work/)
- [Where the figures come from](https://buildbatch.co.uk/sources/)
- [How we compare products](https://buildbatch.co.uk/how-we-compare-products/): what "worked out", "worked example" and "tested" mean on a comparison page.
- [Questions and answers](https://buildbatch.co.uk/faq/)
- [About BuildBatch](https://buildbatch.co.uk/about/)
- [How BuildBatch is paid](https://buildbatch.co.uk/how-buildbatch-is-paid/)
- [Privacy](https://buildbatch.co.uk/privacy/)

## Optional

- [Every guide, table, example list, cost page and product page, then every guide in full](https://buildbatch.co.uk/llms-full.txt): each with its one-line answer, then the full text of every guide and the questions and answers.