Enhanced construction details

Our enhanced construction details (ECDs) focus on heat losses that occur at the junctions between building elements and around openings. They  improve on the performance delivered by the standard Accredited Construction Details (ACDs) provide in-depth, practical guidance. They are designed to:

• help the construction industry achieve performance standards that exceed those set out in Part L1A of the Building Regulations
• help developers and builders to achieve the energy requirements in the Code for Sustainable Homes.

The details were developed in association with an industry working group. We remodelled and developed the three poorest-performing junctions for all of the standard wall types.

Using the complete set of three ECDs and ensuring that all remaining details achieve the ACD standards will let you use a reduced thermal bridging y-value in SAP of 0.04 W/m²k.

Introduction, use, and thermal bridging

Our introductory document describes how to use our Enhanced Construction Details. It aims to help housing designers, specifiers and builders gain credit for reducing heat loss through the non-repeating thermal bridges that occur between building elements, at corners and around openings. Table 3 describes the construction types as they were modelled within the ECDs.

Read CE297 - Enhanced Construction Details: introduction and use

The follow-up guide provides information and guidance relating to thermal bridging.

Read CE302 - Enhanced Construction Details: thermal bridging and airtightness

PDFs of enhanced construction details

Each detail features a set of rules and a construction sequence checklist. You must follow these to ensure compliance with the thermal performance that each detail achieves.

Some details have been modelled twice to accommodate different approaches in construction (for example, lintels with the window positioned at two extremes within the wall).

Disclaimer

This publication (including any drawings forming part of it) is intended for general guidance only and not as a substitute for the application of professional expertise. Any figures used are indicative only. The Energy Saving Trust gives no guarantee as to levels of thermal transmittance or heat loss, the reduction of carbon emissions, energy savings or otherwise. Anyone using this publication (including any drawings forming part of it) must make their own assessment of the suitability of its content (whether for their own purposes or those of any client or customer), and the Energy Saving Trust cannot accept responsibility for any loss, damage or other liability resulting from such use.

So far as the Energy Saving Trust is aware, the information presented in this publication was correct and current at the time of the last revision. To ensure you have the most up to date version, please refer back to the website The contents of this publication may be superseded by statutory requirements or technical advances which arise after the date of publication. It is your responsibility to check latest developments.

Accredited Construction Details

See the complete set of Accredited Construction Details at the Planning Portal website.