About this asset

This 2026 edition of Approved Document L Volume 2 provides essential statutory guidance for energy efficiency in non-dwelling buildings in Wales. The document serves as the official regulatory framework for the conservation of fuel and power, specifically tailored for buildings other than dwellings within the Welsh jurisdiction. It details the mandatory requirements for thermal performance, heating systems, and the overall minimisation of greenhouse gas emissions during the design and construction phases. The content is structured to guide architects and MEP engineers through compliance pathways, ensuring that new builds and major renovations meet the current environmental standards set by the Welsh Government, reflecting the 2026 regulatory updates for non-domestic building energy performance.

The download is a 1.9 MB file containing .PDF files.

Professionals should integrate these standards into the initial design development and technical specification phases of a project. By referencing the document, designers can verify that building envelopes, HVAC systems, and lighting controls comply with the specified energy performance criteria. It is recommended to keep this digital reference accessible during the BIM coordination process to ensure that all thermal calculations and material selections align with the statutory requirements for non-domestic developments across Wales.

This document is indispensable for architects, sustainability consultants, and building services engineers working on commercial, educational, or healthcare projects in Wales. It is referenced during the planning application and building control submission stages to demonstrate compliance with Part L of the Building Regulations. Designers use this guidance to inform their specification of insulation, glazing, and renewable energy systems, ensuring that every project achieves the necessary energy efficiency ratings required for final certification and ongoing operational performance in the built environment.