Cheltenham cavity wall insulation

External Wall Insulation

Anglian Building Products have been installing External Wall Insulation (EWI) for over a decade, with experience in both the Public and Private sectors.

External Wall Insulation is an energy saving solution for older properties that have little or no insulation. Not only can it increase the lifespan of a building, it also makes the property more energy efficient which can help to reduce running costs. EWI can be considered one of the most effective means of providing building insulation, whilst delivering the broadest range of benefits.


What is External Wall Insulation?

External Wall Insulation (EWI) offers a solution to homes constructed with solid walls to become more thermally efficient.

A layer of insulation is fixed to an existing wall and then finished with either a layer of render or an alternative cladding to protect the insulation.

An EWI solution can be engineered to suit practically any type of building design and construction, with established methods adopted for non-traditional housing, standard specifications of solid walls and more bespoke solutions for new build and many non-domestic situations.

We provide a range of EWI solutions (single or multi-storey, solid wall, non-traditional or cavity construction), which feature a variety of insulation materials which include: expanded polystyrene, extruded polystyrene, polyisocyanurate (PIR), phenolic and mineral fibre.

There are also a wide variety of external finishes available which include: synthetic, mineral, dash, rough cast, brick effect renders, brick slip (synthetic and traditional), timber, board, tile and PVC-U.

Cheltenham cavity wall insulation

Cavity Wall Insulation

Cavity wall insulation is normally suited to brick built properties which were built after the 1920s. It is normally possible to identify whether the walls have cavities by checking whether the bricks are all laid ‘side-on’.

It is estimated that around 9 million homes in the UK have cavity walls, which have yet to be insulated and with more than a third* of all heat being lost through the walls, insulating the cavity provides a cost-effective way to improve comfort levels and reduce energy use in the home.

Cavity wall insulation can be made out of three types of materials:

  • Mineral wool
  • Beads or granules
  • Foamed insulants
  • All three are manufactured according to British standards.


Cavity Wall installation is clean, safe and quick to install. If every UK household suitable was to install it, 4 million tonnes of CO2 every year could be saved and a reduction of up to £140 a year on the householder’s energy bills.

Independent 25 year guarantees are provided by Cavity Insulation Guarantee Agency (CIGA) for all projects.

*Source: Energy Saving Trust website

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Benefits of External Wall Insulation

  • Improved comfort levels
  • Reduced condensation and mould growth
  • Reduction in heating costs
  • Improved external appearance of the property
  • Protection of the buildings structure from weathering and thermal movement
  • Improved energy rating
  • Improved sound insulation
  • Improved fire protection
Thermal Image BEFORE copyright Wetherby Building Systems Ltd

Without insulation

Heat loss from a typical semi-detached
property before the application of
External Wall Insulation.

Thermal Image AFTER Copyright Wetherby Building Systems Ltd

With insulation

The same semi-detached property
after the application of External Wall Insulation


Decorative finishes

A range of decorative renders and brick slip finishes are available, all of which are highly durable and suitable for the toughest weather conditions.

Brick Slip

Brick slips or brick-effect render

Dry Dash

Dry dash with coloured aggregate

Synthetic Aggregate

Light synthetic aggregate with acrylic binder


Why Anglian?

Making positive changes in your community


We provide full technical advice and application support, helping both customers and clients to specify the right solution for each project.

Architects and Consultants


Anglian are accredited to PAS 2030-2035 2019 Certification and are an approved Green Deal Installer. We are also an approved installer member of the Solid Wall Insulation Guarantee Agency (SWIGA) one of the more popular guarantee providers available.


We invest in our workforce with the most up-to-date training through in-house programmes, supplier specific technical training and group academies across the UK, ensuring correct installation and application every time.


EWI Projects

Green Deal approved PAS2030

We are accredited to PAS 2030-2035 2019 Certification and are an approved Green Deal Installer. The Green Deal is a government backed initiative and this certificate confirms we have been accepted as an Approved Installer for the Installation of energy efficient glazing and doors, and external wall insulation.

BSI Quality Management

Anglian Building Products are certified with a fully integrated ISO management system for Quality Standard ISO 9001, Environmental Standard ISO 14001, and Health & Safety Standard ISO 45001 (Certificate No. 16512)