Sources and methodology
Every figure on this site carries a publisher, a document and a date, and anything that could not be sourced is not published at all.
The rules this site follows
- No statistic is published without a source and a date. Where a figure could not be sourced, the page answers the question with a method instead of an average.
- Anything that revises annually says so and shows when it was checked. That covers the Risk Protection Arrangement terms, condition funding rounds and school registers.
- No claim about ADI is made unless ADI has evidenced it. Unverified claims appear as marked placeholders, listed below, rather than as assertions.
- No rating, price, credential or review is marked up in structured data unless it can be cited.
- Every source URL below returned a live page when it was added, on 3 September 2026. Candidate URLs that did not resolve were removed rather than guessed at.
How the school numbers were produced
England's figures are counted directly from the Department for Education's Get Information About Schools extract, downloaded on 3 September 2026. Open establishments are counted, excluding the register's "Other types", "Universities" and "Welsh schools" groups so that a count of "schools" means schools.
Scotland, Wales and Northern Ireland are not covered properly by that register, so each is counted from its own national publication instead. Every regional page states which register its numbers came from, because the three do not count the same things: Scotland records departments rather than phases, Wales publishes maintained schools separately from independent schools and pupil referral units, and Northern Ireland publishes an annual statistical series rather than a live register.
Illustrative diagrams
Two charts on this site show a pattern rather than measured data: the school-year consumption profile and the overnight flow comparison. Both are indexed rather than scaled in cubic metres, and both are captioned as illustrative wherever they appear. No diagram on this site presents an invented number as a measurement.
Every source used
- Source: Department for Education, Get Information About Schools: all establishment data extract (opens in a new tab) ().
- Source: Scottish Government, School contact details, list at 31 January 2026 (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Welsh Government, Address list of schools, April 2026 (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Department of Education, Northern Ireland, Schools and pupils in Northern Ireland, 1991/92 to 2025/26 (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Department for Education, Good estate management for schools (opens in a new tab) ().
- Source: Department for Education, Manage your education estate (opens in a new tab) ().
- Source: Department for Education, School capital funding (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Department for Education, Condition Improvement Fund (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Department for Education, Capital allocations (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Department for Education, The risk protection arrangement (RPA) for schools (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Department for Education, Risk Protection Arrangement (RPA) for Academy Trusts: membership rules, September 2026 (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Department for Education, Make a claim through the risk protection arrangement (RPA) (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Health and Safety Executive, Legionnaires' disease: The control of legionella bacteria in water systems (ACoP L8) (opens in a new tab) ().
- Source: Health and Safety Executive, HSG274 Part 2: The control of legionella bacteria in hot and cold water systems (opens in a new tab) ().
- Source: Health and Safety Executive, Asbestos (opens in a new tab) ().
- Source: Department for Education, Asbestos management in schools and colleges (opens in a new tab) ().
- Source: The National Archives, The Control of Asbestos Regulations 2012 (opens in a new tab) ().
- Source: The National Archives, The Water Supply (Water Fittings) Regulations 1999 (opens in a new tab) ().
- Source: Health and Safety Executive, Construction (Design and Management) Regulations 2015 (opens in a new tab) ().
- Source: Department for Education, Keeping children safe in education (opens in a new tab) (). This figure is restated annually; check the current edition.
- Source: Disclosure and Barring Service, Disclosure and Barring Service (opens in a new tab) ().
- Source: MOSL, MOSL, the market operator for the non-household water retail market in England (opens in a new tab) ().
- Source: Waterwise, Waterwise (opens in a new tab) ().
- Source: Department for Education, Reinforced autoclaved aerated concrete (RAAC) in education settings (opens in a new tab) ().
- Source: MOSL, Our members: trading parties in the non-household water market (opens in a new tab) ().
Open verification items
These are the claims about ADI that this site will not make until ADI evidences them. They are listed publicly because a school evaluating a contractor should be able to see what has and has not been confirmed.
Operator details — vatNumber
ADI to supply the VAT registration number. A school finance team needs it to raise a purchase order.
Operator details — employersLiability
ADI to supply employers' liability cover level and certificate.
Operator details — professionalIndemnity
ADI to confirm whether professional indemnity cover is held, and at what limit. Some trusts ask for it on the supplier form.
Accreditation — ISO 9001
ADI lists this under certifications it is working towards in 2026, not as a current award.
Accreditation — ISO 14001
ADI lists this under certifications it is working towards in 2026, not as a current award.
Accreditation — SafeContractor
ADI lists this under certifications it is working towards in 2026, not as a current award.
Accreditation — DBS checks
ADI’s recruitment page requires applicants to be able to pass a UK DBS check. It does not specify the current check or level held by an attending engineer; confirm these before a school visit.
Accreditation — Asbestos awareness training
The ADI pages checked do not identify an asbestos-awareness provider or current engineer certificates. Request the relevant evidence before work.