Skip to content

UK Building Regulations

Building with ICF in the UK

Significant changes to part L of the Building Regulations were made in June 2022 and are now in force for all dwellings without approval by this time. The impact of these changes will be widespread and force a change in the way homes are built in the UK.

It will not be easy for cavity wall and timber frame buildings to meet the new Air Leakage rules and the higher insulation levels will require cavities that are at least 100mm wide and more time consuming to build.

Air Leakage simply does not occur in ICF dwellings and the additional insulation can be easily added in the form of External Wall Insulation.

UK Regulations.

The latest issue of the Building Regulations Part L – Conservation of Fuel and Power came into force on 15th June 2022. All buildings that do not have Building Regulation approval on the 15th June 2022 will come under these Regulations.

These are divided into two parts:
Volume 1: Dwellings & Volume 2: Buildings other than Dwellings

The guidance in Approved Document L, Volume 1 applies to dwellings only.
In a mixed-use building, Approved Document L, Volume 2: Buildings other than dwellings should be consulted for building work in parts of the building that are not dwellings.

Dwellings are self-contained units for a single family. Rooms for residential purposes and buildings that contain only rooms for residential purposes are not dwellings and Approved Document L, Volume 2: Buildings other than dwellings would apply.

See the full documents:

Volume 1: Dwellings

Volume 2: Buildings other than Dwellings

*The notional U Value for walls in Dwellings is 0.18 W/m2-K (Page 12).

*The notional U Value for walls in Buildings other than Dwellings is 0.26 W/m2-K (Page 25).

Using PolyBloks to meet Part L Requirements.

Polybloks can meet the Part L requirement of a notional U value of 0.18 W/m2K using External Wall Insulation. Alternatively, many builders may prefer to use insulated plasterboard on the internal PolyBlok faces as this needs less surface area and does not introduce another construction operation. For more information on the energy efficiency of our PolyBlok ICF, please click here. If required, PolySteel can supply the External Wall Insulation in easily fixed 2.4 x 1.2 m panels along with your ICF blocks.

External Wall Insulation (EWI).

Meet New Regulation Standards

The ICF industry has provided products to meet the reduction in the U-value of dwelling walls in different ways. Polysteel considers that the addition of EWI is currently the easiest and most economic approach. The manufacture of new production moulds for wider blocks is a costly process and no one knows what the requirements will be when they are changed again in 2025.

Simple & Quick Installation

The addition of EWI is a simple, very quick process, as illustrated in the sketch below. The sheets of EWI can be fixed in any weather conditions after the concrete has been poured and the rest of the building is being finished. At a fixing rate of 15 No 1200 x 600 x 50 mm sheets per hour it will take a two-man crew about a day on an average per dwelling.

No Interference

The Addition of External Wall Insulation does not interfere with the reinforcement that is always required for basement walls or reduce the room size inside.

Application of 50mm EWI Boards


ICF Construction

Call us if you need more detailed information for your ICF project, browse our technical library and FAQs for construction details using Polybloks.