External Wall Insulation

External Wall Insulation (EWI), also referred to as Insulated Render, Solid Wall Insulation (SWI) and External Thermal Insulation Composite Systems (ETICS) and have been used in the UK for over six decades.

The use of EWI systems has increased significantly in the last 10 – 15 years and they are suitable for both new build and refurbishment projects, but particularly beneficial for the aging housing stock we currently have in the UK.

The UK have approximately 12 million homes that either have no insulation or insulation that only meets the standards of 1976 or before. These poor levels of insulation could be costing homes more than £1,000 per year if there are no improvements made to the thermal efficiency of the fabric of the building.

EWI is typically a sandwich constructed system, applied externally to the substrate of the building, and provides a high level of thermal upgrade in addition to improving the internal climate and air tightness of the property. This makes EWI an excellent solution to the poor insulation of these homes, as well as providing a new fresh weather resistant appearance to the facades.

PRB has a range of external wall insulation systems (EWIS), PRB THERMOLOOK (EPS), THERMOROCHE (Mineral Wool) or THERMOBOIS (Wood Fibre) and feature a variety of insulation materials, reinforcement layers and surface finish options that are suitable for a wide range of substrates for both new and renovation projects making it possible to create functional, durable and beautiful facades.

Advantages of external wall insulation systems

• High levels of thermal insulation achievable with insulation thicknesses up to and over 200mm including to passive house standard.
• Multiple insulation options to suit low rise, high rise buildings, with insulations suitable for many masonry constructions, lime mortar constructions and frame constructions.
• Increases the internal climate comfort, offering both a cooling in the summer and warming in the winter effect and can help reduce physical symptoms associated with colder, damper properties.
• A2 Fire rated systems using non combustible materials.
• Improved thermal performance, minimising thermal bridging and reducing the condensation risk.
• Cost-effective low carbon solutions for new build or renovation projects
• Reduction of energy costs, which are dependent upon the type of property itself, but this could range from £250 per year for a mid-floor flat to over £1000 per year for a detached property.
• A reduction in CO2 emissions, ranging from around 400 kg to over 1500 kg annually.
• An improvement in sound reduction.
• No loss of any internal room space which will happen if internal wall insulation is used.
• An increased improvement in the weather and wind protection of the external walls.
• An increase in the durability of the external walls, improving the lifespan of the property.
• A new fresh appearance for the property with a wide range of textures and colours available.
• For large scale programs where multiple properties are being treated, the better living conditions, the visual upgrading and refreshing of the façades can have a positive impact on the local community.
• EWI can be installed onto many different types of existing properties including non-traditional built homes.
• Following the installation of EWI, the value of the property will be increased. Surveys undertaken have shown an approximate £16,000 increase in a property’s value from changing the EPC (Energy Performance Certificate) from a Band G to E. Market research has also shown a pre and post installation value change of a property of 8% – 12%.
• No internal disruption during works.
• For landlords, EWI is more cost effective when used on multiple properties.

Benefits of the PRB insulations systems

• Third party accredited systems with BBA and ETA certifications.
• PRB Pro Contractors available to install the systems, who can also provide a PRB system guarantee.
• Multiple insulation options, including non-combustible materials.
• Multiple finish options & materials, including mineral render finishes, thin coat systems with the benefit of offering dark colour shades and brick and stone slip options.
• High resistance to impact resistance with the option for enhanced impact resistance.
• Excellent weather performance including exposed locations and next to the coast.
• Fully breathable systems, permeable to water vapour and CO2 with solutions that are compatible with the fabric of the building and its use.
• Cement-free, ready-to-use system components available.

Download our technical guide for how to use EWI.