Discover the typical cost of house extension plans in the UK, including planning drawings, Building Regulations drawings, measured surveys and common extras. This homeowner guide explains what affects extension plan prices, how much architects may charge, what is normally included, and how to compare quotations properly before committing to your project
House extension cost per m2 in the UK can vary widely depending on size, location, specification, access and structural complexity. This guide explains realistic 2026 extension cost ranges, single vs double storey pricing, key extras to budget for, and how to calculate a more reliable total before asking builders for quotations.
Thinking about a rear and side extension? This guide explains what counts as Permitted Development, when you’ll need full planning permission, and how to design with neighbours and council rules in mind. Learn costs, timelines, structural needs and local quirks, plus practical tips to make your extension a smooth success.
