Tag: Approved Document L

Cross-section diagram of a residential house highlighting key energy efficiency components such as insulation, airtightness, ventilation, and high-performance materials, in compliance with Building Regulations Part L.

Building Regulations Part L: Insulation, Energy Efficiency & What You Must Know

December 14, 2025 No Comments

Building Regulations Part L sets the energy efficiency rules for UK home projects. This guide explains what Part L covers, how U-values and insulation affect extensions and conversions, and why ventilation (Part F) matters when you improve airtightness. Learn what Building Control looks for, what evidence to keep, and how to avoid costly changes mid-build.

A construction planning table displaying documents and diagrams related to Building Regulations U Values, including insulation layers, compliance checklist on a digital tablet, and U-value targets for walls, roofs, and windows in a partially built home extension.

Building Regulations U Values Explained – What They Mean and Why They Matter

October 31, 2025 No Comments

Understand Building Regulations U Values and why they matter when building, extending or converting your home. This guide explains the current 2025 U Value limits for walls, roofs, windows and floors — and how to comply. Avoid common pitfalls and ensure your insulation meets the UK standards for Building Control sign-off.