External Wall Insulation

At E Z External Wall Insulation and Rendering, we understand the significance of energy efficiency and comfort within your property. We specialise in top-quality External Wall Insulation (EWI) services designed to enhance your building’s thermal performance while providing a range of additional benefits. Whether it’s a residential or commercial property, our skilled team is dedicated to helping you create a more sustainable and comfortable living or working space.

What is External Wall Insulation?

EWI is a method of upgrading the thermal performance and external appearance of existing properties.

EWI is a thermally insulated, protective, decorative exterior cladding procedure involving the use of expanded polystyrene, mineral wool, polyurethane foam or phenolic foam, covered with a reinforced high polymer modified render, finished with Acrylic or Silicone render.

The thickness of the insulation that will be fixed to wall dependents on the type of insulation. Different types of insulation material has different thermal values. When calculating the actual insulation requirements, consideration must be given to current Building Regulation standards. Consideration must also be given to exposure and durability, and whether the structure might be subjected to vandalism etc. In many older properties, special attention is required for concrete beams or lintels which act as thermal bridges providing poor insulation.

If your home was built before the 1920s, it’s likely the external walls are solid walls rather than cavity walls.

Solid walls have no gap, so they can’t be filled with cavity wall insulation.
Cavity walls are made of two layers with a gap or ‘cavity’ between them.
Solid walls can be insulated by adding an insulating layer, either on the inside or the outside, to prevent heat escaping through your walls while keeping the cold out.

If you insulate your solid wall from inside it is called internal wall insulation and you lose your very precious floor space and it incurs additional decorating costs, not to mention the inconvenience of having some insulation work done to all your walls at the same time while you are living in the house. If you insulate your solid wall from outside it is called External Wall Insulation.

External Wall Insulation insulation is usually more effective at cutting your energy bills than cavity wall insulation.

Understanding External Wall Insulation (EWI):

External Wall Insulation (EWI) is a method aimed at insulating a building’s external walls to improve its energy efficiency. This involves applying an insulating layer to the exterior walls, followed by a protective rendering system. EWI helps prevent heat loss, reduces energy consumption, and lowers heating expenses. Additionally, it improves thermal comfort, minimises condensation, and enhances the overall appearance of your property.

Also known as Solid Wall Insulation (SWI), External Wall Insulation is highly effective in improving the thermal performance and energy efficiency of buildings with solid walls. Unlike cavity walls that have a gap between the inner and outer layers, solid walls lack this cavity, leading to poor insulation properties. External Wall Insulation rectifies this by applying an insulating layer to the external surface, reducing heat loss, preventing thermal bridging, and enhancing the property’s overall energy efficiency. This comprehensive insulation system not only improves occupant comfort but also reduces energy consumption and heating costs. Additionally, External Wall Insulation can rejuvenate a building’s appearance, providing a fresh, modern look while enhancing its insulation capabilities.

Our Range of EWI Services Includes:

Free Site Assessment and Survey: We start with a complimentary site visit and survey to assess your property. Our experts evaluate existing conditions, discuss your requirements, and provide tailored professional recommendations.

Free Comprehensive Estimate and Written Quotation: After the site visit and survey, we provide you with a detailed estimate and a written quotation at no cost. We believe in transparency to ensure you have a clear understanding of the project scope and associated costs.

Customised Design and Specification: Our experienced team collaborates closely with you to design an EWI system aligned with your vision and requirements. Considering insulation materials, finishes, architectural style, and sustainability goals, we create a customised solution for your property.

Guidance and Expert Consultation: We value open communication and provide comprehensive consultation throughout the process. Our knowledgeable team offers expert advice, answers your questions, and assists in making informed decisions based on your needs and budget.

BBA-Approved Systems and Materials: To guarantee high standards of quality and durability, we exclusively use EWI systems and materials approved by the British Board of Agrément (BBA). This certification ensures our solutions meet stringent industry standards and undergo rigorous testing and assessment.

Manufacturer-Approved Installation: As a trusted installer, we have partnerships with reputable manufacturers. Our approved installer status enables us to offer extended warranties and access the latest advancements and technologies in EWI.

Fully Insured Contractor: Your peace of mind is our priority. We are a fully insured contractor, covering liability insurance, worker’s compensation, and property damage protection, ensuring comprehensive coverage during the project.

Expanded Polystyrene (EPS): Also known as EPS, Expanded Polystyrene stands as a lightweight and cost-efficient insulation material extensively utilised in EWI systems. These EPS boards boast exceptional thermal insulation properties and come in various thicknesses to cater to specific insulation needs. EPS is easily handled, exhibits good resistance to moisture, and showcases high compressive strength, ensuring durability and prolonged performance.
EPS demonstrates a low thermal conductivity, denoted by its Lambda value (λ), typically falling within the range of 0.030 W/m·K to 0.040 W/m·K. Its cost-effectiveness renders it a popular choice for numerous projects.

Types of Materials We Use for External Wall Insulation:

Mineral Wool: Recognised as Rock Wool or Stone Wool, Mineral Wool proves to be a versatile and highly efficient insulation material employed in EWI systems. Derived from natural rock or mineral fibres, it offers excellent thermal and acoustic insulation properties. Mineral Wool is fire-resistant, non-combustible, and provides effective protection against heat loss, condensation, and noise transmission. Available in various forms—batts, rolls, and rigid boards—it allows for adaptable installation options.
The Lambda value of mineral wool insulation typically spans from 0.032 W/m·K to 0.040 W/m·K. Mineral wool insulation stands as a competitively priced option, delivering good value for money.

Phenolic Foam: Phenolic Foam represents a high-performance insulation material renowned for its exceptional thermal efficiency and fire resistance. Possessing excellent thermal conductivity, it outperforms other materials in providing superior insulation with thinner insulation thicknesses. Phenolic foam, lightweight and moisture-resistant, guarantees long-term durability. Often utilised in limited space scenarios or where heightened insulation performance is required.
Its low thermal conductivity usually falls between 0.018 W/m·K to 0.022 W/m·K, distinguishing Phenolic foam insulation for its superior thermal insulation with thinner insulation thicknesses. It stands as a premium option, albeit with a higher cost compared to other materials.

Expanded Polystyrene (XPS): Renowned for its remarkable thermal insulation properties, XPS features a closed-cell structure offering high resistance to heat transfer. This characteristic effectively minimises thermal bridging and heat loss through external walls. Its inherent resistance to moisture and high compressive strength safeguards the structural integrity of building envelopes, making it an ideal choice for insulating below the damp course.
The Lambda value of XPS typically ranges from 0.028 W/m·K to 0.038 W/m·K, contingent on the specific product and thickness. Note that insulation material costs may vary based on factors like thickness, density, market conditions, and project requisites.

Polyurethane (PUR) and Polyisocyanurate (PIR) Foam: These closed-cell insulation materials, commonly referred to as PUR and PIR foam, offer excellent thermal insulation properties. These foam insulation boards possess a high insulation value, ensuring exceptional energy efficiency. With low thermal conductivity, they effectively diminish heat loss and bolster a building’s energy performance. Lightweight, moisture-resistant, and easy to install, PUR and PIR foam boards remain a sought-after choice for EWI systems.
They exhibit low thermal conductivity, with Lambda values ranging from 0.022 W/m·K to 0.028 W/m·K. PUR and PIR foam insulation, while pricier than EPS or mineral wool insulation, deliver superior thermal performance.

Cork Insulation: A natural and eco-friendly alternative for EWI systems, Cork insulation stems from the bark of cork oak trees and offers commendable thermal insulation properties. As a breathable material, it regulates moisture and provides soundproofing benefits. Lightweight, fire-resistant, and resistant to pests, Cork insulation boasts an extended lifespan. Often applied as an additional insulation layer or a finishing coat in EWI systems.
The Lambda value of cork insulation typically ranges from 0.040 W/m·K to 0.050 W/m·K. Renowned for its breathability and additional advantages such as moisture regulation and soundproofing, Cork insulation stands as a premium option albeit with a higher cost compared to other materials.

Why chose us?

Highly Qualified Workforce: Our team comprises highly skilled and qualified professionals with extensive experience in EWI installations. We invest in ongoing training to ensure our workforce remains up-to-date with the latest industry practices and techniques.

Comprehensive Guarantees and Warranties: We stand behind the quality of our workmanship and materials. We offer extensive guarantees and warranties on our EWI installations, providing assurance that your investment is protected and any issues will be addressed.

Experienced, Established, and Reputable Business: With years of experience and a solid reputation in the industry, we have gained the trust and loyalty of numerous satisfied clients. Our commitment to delivering exceptional results, outstanding service, and superior craftsmanship sets us apart as a reliable and reputable business.