Fabric first: how EWI reduces reliance on heating systems

Recent research has revealed a growing trend among homeowners to switch to External Wall Insulation (EWI). According to the Baumit study, this ties up with a significant increase in homeowners and self-builders’ knowledge about the benefits of EWI. 

Here, Matthew Woodhams, Technical Specification Manager at Baumit explains why this shift is happening. 

The findings of research recently commissioned by Baumit carried out with Ipsos indicate that 31% of homeowners are now aware of the advantages of EWI. It is little surprise that this coincides with energy costs reaching record highs over the past two years. This increased awareness of EWI is linked to the fact that more homeowners and self-builders are seeking effective solutions to improve energy efficiency.  While the research results are encouraging and demonstrate that homeowners consider energy efficiency a major factor, there is still room for improvement in terms of the ‘Fabric First’ mindset. 

In terms of this approach, EWI is an excellent way to counteract rising energy costs and future-proof homes against potential cost fluctuations in the years to come. The survey goes on to reveal that homeowners are twice as likely to prioritise replacing their boiler or installing solar panels over ensuring their walls are properly insulated. We always point out to customers that they should improve energy efficiency of the building fabric first.

Once they have decided on this kind of approach, breathable external wall insulation is one of the most effective methods of enhancing a home’s energy efficiency without sacrificing living space. This is crucial because when it comes to selling a house, square footage and running costs are key factors in terms of value and attracting potential buyers.

In addition to creating energy-efficient homes, breathable EWI enhances the aesthetic appeal of buildings, making them more desirable places to live. A prime example is Kings Knoll, a Grade 2 Listed Art Deco building from the 1930s that we supplied, situated on the River Deben in Suffolk. The family home was renovated using our EWI system, while still preserving its original architectural features.

The property now benefits from 100mm wood fibre EWI system, finished with our SilikonTop, Life Colour 0879, also known as Ceramic White. The breathable EWI contributes to healthier living spaces by allowing moisture from everyday activities such as cooking and showering to escape outside, reducing the growth of mould and the accompanying airborne particles it produces.

Fit for a king

Application of external wall insulation on projects such as Kings Knoll involve applying an insulating material to the outer walls of the building, such as wood fibre or breathable EPS. This is followed by the addition of reinforcing mesh and render, a process that not only enhances the thermal efficiency but also provides a protective layer against external elements such as rain, sunlight, and temperature fluctuations. The versatility of renders allows homeowners to achieve the desired finish and even increase the value of their property. 

With a wide range of renders available, homeowners can choose a finish that suits their personal taste and which elevates the visual appeal of their property. Whether opting for a traditional or contemporary look, external wall insulation offers the opportunity to transform the appearance of a home and increase its curb appeal.

In addition to its thermal benefits, external wall insulation can improve acoustic performance for the occupants by reducing noise transmission from the outside, creating a quieter and more peaceful internal living environment.

Self Builds

External wall insulation is increasingly popular in new build projects due to its cost-effectiveness and long-term energy saving benefits. By incorporating EWI from the outset, self-builders can simplify the design process, meet sustainable building requirements, and conserve energy. The advantages of external wall insulation for new build schemes include simplicity in design, fast-track build programs, energy conservation, compliance with building regulations, and the potential to qualify for funding opportunities.

Retrofitting Existing Properties

For existing properties, external wall insulation offers a transformative solution to improve energy efficiency and thermal performance. Retrofitting solid-wall properties – there are around 8 million of these homes in the UK – with EWI minimises disruption to occupants while delivering significant benefits. Key advantages of external wall insulation for retrofitting purposes include enhanced thermal performance, minimal disruption, a wide range of colour and finish options, preservation of the building’s original character, no loss of internal space, increased property value, and extended lifespan.

Choosing the Right Insulation Materials

When selecting insulation materials for external wall insulation, homeowners and self builders have a range of options to consider. Each material has its own advantages and considerations, such as ease of installation, and environmental impact. The two main materials used are wood fibre board and expanded polystyrene (EPS).

Wood fibre insulation boards are an environmentally friendly option because they are made from renewable and sustainable materials. They provide excellent thermal insulation and moisture management properties.

EPS insulation is a lightweight, cost-effective and easy to install material that is available in various thicknesses to suit different requirements. Breathable EPS such as StarSystem is a good choice because it allows the walls to breathe as does wood fibre, avoiding trapped moisture inside the home and creating optimal living conditions. EPS is also a popular choice due to its affordability and ease of installation, whilst providing excellent thermal insulation.

Other EWI insulation materials include mineral wool, which is non-combustible and breathable as well as offering excellent thermal performance. Wood fibre insulation is another natural, breathable option that maintains the moisture balance of the property.

EWI: a fabric first approach

External wall insulation is a crucial element of a fabric first approach because it prioritises the use of materials and techniques to improve the energy efficiency and comfort of a building, without relying heavily on mechanical systems. 

The many that the thousands of homeowners being encouraged to replace boilers and fit solar panels might do well to consider the fact that this kind of fabric first approach often delivers benefits quicker and for the longer term.