EWI Benefits – 18 Reasons For Installing External Wall Insulation

External wall insulation (EWI) is a cost-effective way to insulate your home – particularly if your home is built with solid brick, block or stone walls or a cavity that is not suitable for insulating. It provides a considerable number of benefits and advantages that improve the comfort of your living space, increase the long-term value of your property and reduce your energy bills. You’ll also be doing your bit for the environment too!

Below we highlight 18 reasons for installing external wall insulation in your home.

1- Increased Thermal Comfort

EWI can ensure that the temperature inside your property is ideal for feeling comfortable regardless of the weather outside. Insulation keeps the heat generated by your central heating system / renewable heating inside the building while also keeping cold outside air from entering. In the summer EWI keeps walls from absorbing heat radiated by the sun allowing for a more comfortable indoor temperature and keeping your property cool.

2- Lower Energy Bills

Energy bills are drastically reduced when heat is retained within your property. When external wall insulation is installed on all property types homeowners and tenants can save a substantial sum of money on energy bills. Although EWI can be costly to initially install, it pays for itself over time through energy bill savings.

Installed correctly, EWI will reduce heating bills significantly. By exactly how much will depend on the property and the type / thickness of insulation used but it can by as much as 35% or even more. Reseach from Northumbria University suggest the average household saving to be 33%: researchportal.northumbria.ac.uk.

3- Improve the Appearance of Your Property

Adding EWI to your property also provides an opportunity to refresh its appearance. With different textures, hundreds of unique colours, brick-effect finishes, pebble dash finishes and brick slips available, property owners can choose from a wide range of low maintenance and durable decorative finishes.

Architectural details such as quoins, profiles and ashlar grooves can also be made through innovative installation or ewi and renders.

4- Retain Internal Floor Space

With the ever growing need to insulate our homes due to rising energy costs, if cavity wall insulation is not appropriate we are faced with 1 of 2 options:

1. External wall insulation (EWI) – insulating the external walls of the property
2. Internal Wall Insulation (IWI) – insulating the internal wall of the property

When compared to IWI the big advantage to EWI is that it doesn’t result in any loss of internal living space at all. The entire structure is encased in insulation, which is adhered to the exterior walls with adhesive and mechanical fixings. The wall become thicker but the increase in thickness is added to the outside of the builing and not on the internal walls. This is especially useful in properties where the internal space is limited.

5 – Reduce Your Carbon Footprint

Because of its high levels of insulation, EWI significantly reduces your carbon footprint by requiring less gas and electric heating / renewable heating throughout the year. The reduction in the need to run central heating & renewables as much or to the same levels means the carbon footprint and the production of greenhouse gas is reduced.

6 – Improve The EPC Rating

An Energy Performance Certificate (EPC) assesses a property’s energy efficiency. Property owners and landlords can improve the EPC rating of their home or rental property by installing EWI, making their home more appealing to potential buyers and tenants. EWI has a significant impact on the EPC methodology used to calculate the ratings which will benefit landlords needing to increase their property rating to band C or better.

7- Extend the Life of Building Fabric

External wall insulation shields the building fabric from the elements. The external render or decorative finish that completes the system acts as a waterproof barrier, preventing water ingress and damage from extreme weather. This contributes to the fabric’s longer lifespan.

In the case of render finishes, unlike traditional sand and cement based renders, EWI finishes are typically silicone based and flexible, maintaining hydrophobicity and allowing for some movement within the building without cracking. This prevents the rick of thermal shock which can lead the structural cracking in masonary substrates.

8 – Minimise Thermal Bridging

Thermal bridging occurs when gaps in an insulation system exist. Heat loss is significantly higher through these gaps, causing heat to be concentrated and allowing water and condensation to collect. Thermal bridging can significantly reduce insulation effectiveness and can cause surface condensation which leads to mould growth.

There are many thermal bridges that cannot be overcome when using IWI, party walls, bathroom and kitchen utilities etc but, in the case of EWI, the system is external and completely seamless therefore reducing risk.

9 – Reduce Condensation And Risk Of Mould

By retaining heat within the walls insulation slows the rate of heat transfer. Condensation occurs when hot air collides with cold walls. Because EWI warms the property’s exterior walls, condensation is greatly reduced, helping to minimise the risk of mould, improve indoor air quality and maintain structural integrity.

10 – Peace Of Mind

EWI typically comes with a 25-year warranty, or an insurance backed guarantee giving you peace of mind and ensuring that you’re covered for any system failures caused by materials, workmanship or design.

11 – Minimal Disruption

EWI is less disruptive than internal solid wall insulation, making it a good choice when it comes to insulating your property. The installation of IWI typically requires modifications to flooring, plumbing, electrics, kitchen units, bathrooms, wall features and many more. Whilst IWI can be a good option when a property is being completely renovated, it is far from ideal for occupied properties.

There is no such disruption with external wall insulation – all works are carried out externally and so you can remain in the property undisturbed whilst installation is ongoing.

12 – Increases Fire Resistance

EWI systems fully conform to all UK fire regulations and can improve the fire resistance of a building. The insulation material can be chosen based on its fire resistant properties and the finishing layer can be made with materials that have been tested to withstand high temperatures. This can give property owners peace of mind knowing that their property is better protected against fire.

13 – Provides A Sound Barrier

External wall insulation can also help reduce noise pollution by acting as a sound barrier. The insulation layer can absorb sound waves and reduce the amount of noise that enters the building. This is especially beneficial for homes located in noisy areas such as busy roads or near train tracks.

14 – Long Term Maintenance Scheduling

External wall insulation can benefit the home by increasing the lifespan of the fabric and in doing so will reduce the long term maintenance costs.

15 – UK Government Funding

Government funding is available toward the cost of installing EWI. There are various funding streams available depending on where you reside, your personal situation and the type of property you live in. Funding is available to social landlords private landlords and homeowners to help meet government net zero / energy saving targets.

16 – Health Benefits

An NHS study entitled Health gains from home energy efficiency measures: The missing evidence in the UK net-zero policy debate examined the health gains from a programme of external wall insulation works to homes, and in particular the impact upon hospitalisations for respiratory and cardiovascular conditions.

The installation of external wall insulation reduced the inability to achieve thermal comfort in winter by two-thirds and these improvements in thermal comfort resulted in proven gains in physical health scores. Relative standardised hospital admissions fell in the treatment areas, remaining lower than the district-wide standardised rate for the majority of a five year period, this effect ending during the Covid-19 pandemic. The impact on admissions was greater for respiratory conditions than for cardiovascular conditions.

17 – Social Impact Associated With EWI

Householders report that benefits associated with the installation of install of EWI include:

• improved thermal efficiency
• external noise reduction
• improved comfort levels
• reduced energy bills
• kerb and community improvement resulting from improved external appearance to their homes and community

18 – Regulation & Control

All suppliers of EWI systems within the UK are heavily regulated by various government agencies, ensuring all systems are thoroughly tested and fit for purpose on all property types and tenure. Third party certification provides peace of mind to tenants, homeowners, and social landlords.

Conclusion

With so many benefits can prove to ba a highly cost effective energy efficiency measure. Addressing the very fabric of the building itself and making your home as thermally and energy efficient as possible thereby maximising the benefits of any additional improvements made to heating systems, renewable energy generation and suchlike.

Save money, improve health, give new life to your home and do your bit for the environment too!

About INCA

• INCA is the recognised trade association for the External Wall Insulation (EWI) industry representing system designers, specialist installers and key component suppliers
• INCA has proven longevity as a trade body dating back 40 years. Please refer to the INCA website for a current breakdown of our membership types: contractors, manufacturers, and associates
• INCA’s vision: The delivery of growth in sustainable fabric performance solutions as the primary focus in combating fuel poverty and protecting the environment
• INCA’s mission: To represent and support members of the External Wall Insulation industry through technical excellence, effective collaboration, strong communications, and member benefits