Kingspan Insulation - Part L Building Regulations 2013

Building Regulations

Kingspan Group Kingspan Insulation

Building Regulations and Standards


Building Regulations Simplified

Building Regulations / Standards set the levels of thermal insulation required when carrying out building work, either for new build or refurbishment projects. These are expressed as a U-value which needs to be achieved. The required U-value will depend on the location of the project (England, Scotland, Wales), type of building (domestic, non-domestic) and the application (floor, wall, roof).

The tables below show the suggested U-Values in England, Wales and Scotland. Note the distinction between the Domestic and Non-Domestic columns. Below that, there are more detailed guides to the thermal insulation parts of Building Regulations / Standards.

Our free online U-Value Calculator will also help. Use it to see what thickness of insulation you need for your location and application.

Recommended U-Values - England

  Domestic Non-Domestic
New Build Existing Buildings New Build Existing Buildings
Best Starting Point (Fabric Only) Extension Refurbishment Best Starting Point (Fabric Only) Extension Refurbishment
Wall 0.16 0.28 0.30 / 0.55 * 0.22 0.28 0.30 / 0.55 *
Floor 0.11 0.22 0.25 0.18 0.22 0.25
Pitched Roof - Ceiling Level 0.11 0.16 0.16 0.14 0.16 0.16
Pitched Roof - Rafter Level 0.11 0.18 0.18 0.14 0.18 0.18
Flat Roof 0.11 0.18 0.18 0.14 0.18 0.18
* A U-value of 0.55 W/m2K is used for cavity insulation and 0.30 W/m2K for internal or external wall insulation.


Recommended U-Values - Wales

  Domestic Non-Domestic
New Build Existing Buildings New Build Existing Buildings
Best Starting Point (Fabric Only) Extension Refurbishment Best Starting Point (Fabric Only) Extension (Domestic in Character) Extension (Other Buildings) Refurbishment
Wall 0.16 0.21 0.30 / 0.55 * 0.22 0.21 0.26 0.30 / 0.55 *
Floor 0.11 0.18 0.25 0.18 0.18 0.22 0.25
Pitched Roof - Ceiling Level 0.11 0.15 0.16 0.14 0.15 0.15 0.16
Pitched Roof - Rafter Level 0.11 0.15 0.18 0.14 0.15 0.18 0.18
Flat Roof 0.11 0.15 0.18 0.14 0.15 0.18 0.18
* A U-value of 0.55 W/m2K is used for cavity insulation and 0.30 W/m2K for internal or external wall insulation.


Recommended U-Values - Scotland

  Domestic Non-Domestic
New Build Existing Buildings New Build Existing Buildings
Best Starting Point (Fabric Only) Extension & Refurbishment * Conversion of Heated Buildings Best Starting Point (Fabric Only) Refurbishment, Extension & Conversion of Unheated Buildings Conversion of Heated Buildings
A B
Wall 0.15 0.17 0.22 0.30 0.18 0.25 0.30
Floor 0.13 0.15 0.18 0.25 0.15 0.20 0.25
Pitched Roof - Ceiling Level 0.10 0.11 0.15 0.25 0.14 0.15 0.25
Pitched Roof - Rafter Level 0.10 0.13 0.18 0.25 0.14 0.15 0.25
Flat Roof 0.10 0.13 0.18 0.25 0.14 0.15 0.25
* Column A is for extensions where the existing dwelling's walls and roof U-values are worse than 0.70 W/mK in the walls and worse than 0.25 W/mK in the ceiling. Column B is for other extensions, upgraded existing thermal elements, non-exempt conservatories and conversion of unheated buildings.

Click here for a printable version of these tables.

The requirements for the conservation of fuel and power, which includes thermal insulation, in buildings in England are detailed in Approved Documents (AD) L1A, L1B, L2A and L2B to the Building Regulations 2013 which come into effect on 6th April 2014.


Our Guides to the Latest Regulations

England 2013 Building Regulations Guides
L1A New Build - Dwellings
L1B Existing - Dwellings
L2A New Build - Buildings other than Dwellings
L2B Existing - Buildings other than Dwellings

Wales 2014 Building Regulations Guides
L1A New Build - Dwellings
L1B Existing - Dwellings

L2A New Build - Buildings other than Dwellings

L2B Existing - Buildings other than Dwellings


Scotland Building Standards Guides
Section 6 - Domestic Buildings
Section 6 - Non Domestic Buildings

Useful Resources

Kingspan Insulation U-Value Calculator
3 things you need to know about Part L 2013

Building Regulations and SAP
What can we expect from Part L Building Regulations

Building Regulations Official Documents

England 2013 Building Regulations Official Documents
L1A New Build - Dwellings
L2A New Buid - Buildings other than Dwellings
L1B Existing - Dwellings
L2B Existing - Buildings other than Dwellings
Amendments to the Approved Documents L1B and L2B 

Wales 2014 Building Regulations Official Documents
L1A New Build - Dwellings
L2A New Buid - Buildings other than Dwellings
L1B Existing - Dwellings
L2B Existing - Buildings other than Dwellings

Scotland Section 6 2015 Official Documents
Scottish Building Standards 2015

Previous Guides

2010 Building Regulations Guides
L1A New Build - Dwellings
L2A New Build - Buildings other than Dwellings
L1B Existing - Dwellings
L2B Existing - Buildings other than Dwellings