Building Regulations and Thermal Efficiency
15th October 2018

Building Regulations and Thermal Efficiency

The energy performance of a building has been a “hot topic” for many years and is continuing to become more important as developments and technologies within construction advance.  With the UK’s desire for zero-carbon new-build homes, everything from solar panels, increased insulation and triple glazed windows are increasingly specified.

Building Regulations are minimum standards put in place to achieve the required thermal insulation for design, construction and alterations to buildings throughout Egland, Scotland and Wales. These standards are known as U-Values which measures the thermal efficiency through the heat loss of a building.

A U-Value is measured in W/m²K and is made up of the thermal resistances of all layers that make up a building such as a roof, floor and wall, along with any fixings or air gaps within these elements. The lower the U-Value, the better insulated the building and therefore improve the buildings thermal efficiency.

The tables below show the suggested U-Values around the UK.

England Building Regulations / Standards

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/m²·K is used for cavity insulation and 0.30 W/m²·K for internal or external wall insulation.

Wales Building Regulations / Standards

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/m²·K is used for cavity insulation and 0.30 W/m²·K for internal or external wall insulation.

Scotland Building Regulations / Standards

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/m²·K in the walls and worse than 0.25 W/m²·K in the ceiling. Column B is for other extensions, upgraded existing thermal elements, non-exempt conservatories and conversion of unheated buildings.

Energy Act 2011 – Thermal Efficiency of Commercial Buildings

The UK has also tightened regulations on commercial buildings in an attempt to improve their thermal efficiency, bringing about both costly threats but also opportunities to landlords to improve their buildings energy performance, providing an improved working environment and in turn saving money in the long run with energy bills.

From April 2018, all commercial rented properties must meet a prescribed minimum energy performance standard. Under the Energy Act 2011, the minimum standard has been set as equivalent to an Energy Performance Certificate (EPC) rating of E. As a result, owners of properties with EPC ratings of F or G will, in some circumstances, no longer be able to let these properties until their energy efficiency has been addressed.
[http://building.co.uk/sustainability-minumum-energy-performance-for-commercial-buildings/5069388.article]

Many commercial buildings are single skin buildings with little to no insulation, single glazed windows and old heating systems, our own building here on Bury Road being a prime example of this!! In 2016 we began our own refurbishment project which you can read about here. Our old, tired, single story factory was transformed into a fully insulated and heated double story factory, including a double story office complex.

To improve the insulation of a commercial building is by no means a small task, but one that is a necessity should you wish to continue to rent out or use this building for business. Retrofitted insulation, both wall and roof, can be cut to match the profile of a building such as the “Big 6” profile using expanded polystyrene.

 

 

 

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