Warmer homes. Lower bills.
Lasting results.

Upgrade your property with high-performance External Wall Insulation (EWI) — improving comfort, cutting heat loss, and transforming your home’s exterior.

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Back of a house under construction with exposed insulation, orange window frames, and steps leading to a door. Construction tools are visible on the ground, and part of the yard is shown with grass and sidewalk. The sky is blue with white clouds.

Older or solid-wall homes can lose twice as much heat as modern cavity-wall properties.

Our External Wall Insulation (EWI) systems solve that problem by fixing a layer of high-performance insulation to your exterior walls, finished with a durable, decorative render.

This creates a continuous thermal barrier that keeps warmth in, reduces noise, and gives your home a clean, modern look — all without disturbing your interior.

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Interior of a building under construction with black insulation panels and blue plastic-covered windows.

Benefits of EWI

  • Reduce heat loss and lower energy bills

  • Improve comfort and soundproofing

  • Protect walls from damp, cracking, and weather damage

  • Add value and fresh kerb appeal

  • Installed with minimal disruption

  • Works with a range of decorative render finishes

External Wall Insulation across Kent & South East London

We install external wall insulation systems on properties throughout Kent and South East London.

Our projects span Maidstone, Medway, Tonbridge, Sevenoaks, Dartford, Gravesend, Canterbury and Ashford, as well as South East London boroughs including Bromley, Bexley, Greenwich and Lewisham.

Whether you have a Victorian terrace or a 1960s semi, we carry out a free site survey and recommend the most appropriate EWI system for your property type and budget.

All of our EWI installations are finished with a decorative render topcoat.

Learn more about our silicone render and basecoat systems.

Interior of a building under construction with black insulation boards, two small windows covered with plastic, a steel scaffold, and orange sealing around the windows.

How we work

Preparation & Scaffolding
Safe access and full site protection.

Surface Treatment
Clean, repair, and stabilise the substrate.

Fixing Insulation
High-performance boards adhered and mechanically fixed.

Reinforcing Layer
Basecoat and fibreglass mesh applied for strength.

Topcoat Render
Silicone or mineral finish for colour and weatherproofing.

Finishing Touches
Sealing, detailing, and clean-down for a perfect result.

Frequently Asked Questions

  • External wall insulation is a system where high-performance insulation boards are fixed to the outside of your property's walls, then covered with a reinforced render finish. By wrapping the building in a continuous thermal layer on the outside, EWI eliminates cold bridges, reduces heat loss through the walls significantly, and can make a dramatic difference to comfort levels and energy bills — particularly in older, solid-wall properties that don't have cavity wall insulation.

  • EWI is particularly beneficial for properties with solid walls — typically homes built before the 1920s — which lose significantly more heat than modern cavity wall constructions. It's also used on post-war non-traditional build types, maisonettes, and other property types where internal insulation isn't practical. Some conservation area restrictions may limit options for certain listed or period properties. We'll assess suitability during a free survey visit.

  • EWI is a more significant investment than standard rendering because of the insulation materials, additional fixings, and detailing involved. Costs vary depending on property size, insulation thickness, finish system, and the complexity of the elevation. We provide free, detailed quotes following a site visit — there's no accurate way to quote without measuring the property and assessing the substrate properly.

  • In most cases, EWI on a residential property falls within permitted development rights and does not require planning permission. Exceptions include listed buildings, properties in conservation areas, and those with Article 4 directions removing permitted development rights. If any of these apply to your property, we'll identify this during the survey and advise on next steps.

  • A standard residential EWI installation typically takes 1–3 weeks depending on the size of the property, the number of elevations being treated, and access requirements. The process involves scaffolding, insulation fixing, reinforcing mesh and basecoat application, and the final silicone render finish — each requiring appropriate drying and curing time. We'll give you a detailed programme as part of your free quote.

  • Yes — adding insulation boards to the outside of your walls will extend the external face of the building slightly, which affects the reveals around windows and doors. These are carefully detailed as part of the installation using window trims and reveal beads. In some cases, windowsills may need to be extended or replaced. We account for all of this in our survey and quotation — nothing is left as an afterthought.

Ready to make your home warmer and more efficient?

Fill in the form or speak to our friendly team for advice or a free, no-obligation quote.