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 SAP2005 of 0.04 W/m2k.

To find out how to use the ECDs in line with SAP2009, read our Factsheet: the use of ECDs in SAP2009 .


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).

Wall type



Beam and block

Slab on ground

Suspended timber

Cavity masonry

type 1

MV01 gable

MV01 lintel A

MV01 lintel B

MV01-F01 (A)

MV01-F01 (B)


MV01-F03 (A)

MV01-F03 (B)

Cavity masonry

type 2

MV02 gable

MV02 lintel A

MV02 lintel B

MV02-F01 (A)

MV02-F01 (B)


MV02-F03 (A)

MV02-F03 (B)

Cavity masonry

type 3

MV03 gable

MV03 lintel A

MV03 lintel B

MV03-F01 (A)

MV03-F01 (B)


MV03-F03 (A)

MV03-F03 (B)

Light steel frame SF gable

SF lintel A

SF lintel B

SF01-F01 (A)    

Timber frame

type 1

TF01 gable TF01 lintel

TF01-F01 (A)

TF01-F01 (B)


TF01-F03 (A)

TF01-F03 (B)

Timber frame

type 2

TF02 gable

TF02 lintel A

TF02 lintel B

TF02-F01 (A)

TF02-F01 (B)


TF02-F03 (A)

TF02-F03 (B)


Plasterboard bead

Wall type

Plasterstop bead

Cavity masonry

type 1

PB Pla1

PB Pla2

Cavity masonry

type 2

PB Par1

PB Par2

Cavity masonry

type 3

PB Par1

PB Par2



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.


Contact us

If you are a housing professional – an architect, builder, designer, or developer – and would like more information on our housing technical services, please contact the Housing Technical Services team at HTS@est.org.uk

Our library of technical guidance and case studies for housing professionals covers all areas of new build and refurbishment.