These are the rules every calculator and guide on DIY 123 follows.
Sources
- Rules on planning, Building Regulations and electrical work come from official sources: chiefly the Planning Portal, the Approved Documents and other guidance on GOV.UK, legislation on legislation.gov.uk and the IET for the wiring regulations.
- Every guide links its sources at the bottom. If a rule cannot be traced to a source, it is not on the site.
- Most rules described here apply to England. Where Wales, Scotland or Northern Ireland differ, the guide says so, or tells you to check with your own authority.
Calculators
- Every result states its assumptions, such as bricks per square metre, board size, joint width or wastage allowance, so you can check the arithmetic.
- Prices and running costs are indicative. They depend on your supplier and tariff, and the result says so.
- A calculator never replaces a design by a qualified person. Results for structural, electrical and heating work say this next to the figures.
What these pages will not do
- Claim professional review that has not happened. The site is written by a non-tradesperson, and it says so.
- Tell you that notifiable work can be done without the required approval or certification.
- Recommend products or tradespeople. Advertising never influences content.
Updates and corrections
Each guide shows the date it was last updated. When a regulation changes or a reader reports an error, the page is checked against the source and corrected. To report a problem, use the contact page.