• Rooms can be heated quickly.
• Added insulation thickness reduces the internal room dimensions.
• Structural wall is cold and potentially damp, increasing the risk of condensation
• Installation is disruptive for building occupants.
• Exposure to cold bridges, resulting in condensation, damp and mould.

Cavity Wall Insulation

• One of the most common building insulation methods.
• Cavity construction is expensive and time consuming.
• Thicker wall construction reduces the internal room dimensions.
• Limits options for thermal upgrades in the future.
• Outer leaf construction isn’t insulated or protected, increasing the risk of condensation and freeze / thaw damage

External Wall Insulation

• Structural wall is warm and dry, increasing thermal performance and reducing building maintenance.
• Removal of cold bridges reduces the risk of condensation, damp and mould.
• The heat retention capability of the existing wall is fully utilised.
• Lightweight construction methods can be used, allowing for fast installation.
• Condensation can be eliminated, irrespective of climate conditions.
• Eliminates cracking caused by thermal expansion and contraction, even in mixed blockwork.

Key Insulation Terms

Cold Bridge

Wherever a building element crosses through an externally-facing wall (e.g. floor and ceiling joints; door and window frames) heat can escape through the element. This is especially a problem in concrete and steel framed buildings. Where the temperature of the surface falls below the condensation point of the surrounding air, this can lead to condensation and mould growth inside the building, which is harmful to the health of the building’s occupants.

Cold Spot

Any part of an exterior-facing surface with a significantly lower thermal resistance than the surrounding area. This can lead to a blotchy appearance on a facade, particularly early in the morning.

U-Values

A calculation to determine how much thermal energy in Watts (W) is transported through a building material with the size of 1m² at a temperature difference of 1 Kelvin. The unit of measurement for U-values is W/(m²K). Achieving low U-values reduces the energy used to heat a building, which reduces energy bills and contributes towards saving energy. U-Values are measured in accordance with BS EN ISO 6946:1997.

Building regulations

In the UK and Ireland, ongoing efforts to limit the use of natural fuel resources have been implemented through the UK Building Regulations. As part of the assessment, the Regulations specify maximum U-Values for new buildings. These values are different across the United Kingdom and Ireland, and are currently:

Part L (England, Wales, N. Ireland) – 0.35W/m²K
Part J (Scotland) – 0.3-0.27W/m²K
Part L (Eire) – 0.27W/m²K

Download the Part L1A Guide 2010

Download the Part L1B Guide 2010

External Wall Insulations can explain to you in simple terms what it needs to be done to get your home warm and energy efficient. We are just a call away.