
Trusted by Hundreds of Homeowners Across the Midlands and London
4.7 ★ based on 63 reviews
4.8 ★ based on 49 reviews
5.0 ★ based on 14 reviews
4.7 ★ based on 63 reviews
4.8 ★ based on 49 reviews
5.0 ★ based on 14 reviews
4.7 ★ based on 63 reviews
4.8 ★ based on 49 reviews
5.0 ★ based on 14 reviews
Is My Home Suitable for External Wall Insulation?
Most homes built before 1919 have solid walls - a single skin of brick or stone with no cavity inside. There is nothing in the wall to slow heat down, so it escapes straight through.
External wall insulation - also called outside wall insulation or exterior wall insulation - fixes an insulating layer to the outside face of those walls and finishes it in render. Solid-wall homes are the strongest candidates for it.
Identify Your Walls:
Solid walls have a visible pattern of long and short bricks. Cavity walls only show the long side. If your bricks only show the long side, you have cavity walls - and external insulation is usually not the right answer. We will tell you that at the survey rather than sell you something you do not need.
The Solution:
A layer of insulation on the outside of the wall, finished in render - taking a solid brick wall from around 2.1 W/m²K to 0.30 or better.
Breathable Build-up:
Vapour-open materials let moisture move out of the wall instead of trapping it, which is what stops condensation forming.
What the system is made of:
From the wall outwards: adhesive → insulation board → mechanical fixings → reinforced basecoat with 160 g/m² mesh → primer → silicone render. We use Ceresit systems throughout.
Grey EPS or Mineral Wool
Which System Suits Your Walls?
For most solid brick homes we specify graphite EPS: it reaches the same U-value in less thickness and costs less. For stone or other "breathing" construction, buildings over 18 metres, and anywhere fire performance is critical, we specify mineral wool.
Grey EPS Insulation Boards
Infused with high-quality graphite, these boards provide up to 20% better thermal performance than standard white polystyrene.
✓ Maximised Heat Retention:
Acts as a powerful thermal envelope, cutting heat loss through solid walls from the day it goes on.
✓ Cost-Effective Efficiency:
The most popular choice for modern UK retrofitting, offering the best balance between price and performance.
✓ Moisture Protection:
Correctly installed with our silicone render, it creates a durable barrier against the elements.
Mineral Wool (Rockwool) Systems
Made by melting volcanic rock at around 1,500°C and spinning it into fibres. It is the option we specify where fire performance and breathability matter most.
✓ A1 Fire Resistance:
Completely non-combustible, offering the highest level of fire safety available on the market.
✓ Superior Breathability:
Lets moisture move out of the wall instead of trapping it, which is what stops mould forming.
✓ Acoustic Insulation:
Dense fibrous structure provides an excellent sound barrier, keeping your home quiet and serene.
Expert Material Selection
Our surveyors assess your property to determine the optimal system.
For older stone constructions, we prioritise breathability to reduce the risk of condensation, while for standard solid brick, we focus on thermal density.
Every installation is finished with self-cleaning silicone technology and backed by our 25-year insurance-backed guarantee.
| Feature | Graphite EPS | Mineral Wool |
|---|---|---|
| Thermal conductivity | 0.030-0.031 W/mK | 0.035-0.036 W/mK |
| Thickness for U-value 0.30 on solid brick | ~90 mm | ~100-110 mm |
| Fire classification | Euroclass E | Euroclass A1 (non-combustible) |
| Density | 15-18 kg/m³ | 90-150 kg/m³ |
| Vapour resistance (mu value) | 30-70 | ~1 |
| Acoustic performance | Limited | Good |
| Relative material cost | Baseline | Typically 30-50% higher |
| Best suited to | Solid brick, most domestic retrofits | Stone and "breathing" walls, buildings over 18 m, fire-critical projects |
Typical values for EWI-grade boards. We confirm the specification and U-value calculation for your property before any materials are ordered.
Our recent projects in Bix
See some of our completed EWI and rendering work in the Bix area.

Our Services
Insulated Render Installation & Repairs for Domestic & Commercial Properties
PD Rendering has insulated and rendered more than 750 homes across Coventry, the Midlands and London since 2014.
Chosen and installed correctly, an insulated render system cuts heat loss, reduces condensation and damp, and gives the building a completely new exterior.
External Solid Wall Insulation
Insulation boards fixed to the outside of your walls, in graphite EPS or mineral wool, and finished in silicone render.
✓ Lower heating bills and warmer rooms
✓ Eliminate damp and condensation
✓ 25-Year insurance-backed guarantee
High Performance Render Systems
Upgrade your home's exterior with durable, weather-resistant rendering. We offer a wide range of colours and finishes to suit your style.
✓ Self-cleaning silicone technology
✓ Breathable & weather-resistant
✓ Little maintenance and no repainting
Insulation & Render Repairs
Notice signs of wear, cracking, or damage on your existing render? Our maintenance team restores both the functionality and beauty of your walls.
✓ Professional crack repairs
✓ Patching and colour matching
✓ Preventative maintenance
Common Questions
Everything You Need to Know
Got questions about EWI or silicone rendering? We’ve compiled the answers to help you make an informed decision for your property.
Is my home suitable for External Wall Insulation (EWI)?
Most UK properties built before 1919 feature solid external walls devoid of a cavity.
These are the perfect candidates for EWI, as they permit a substantial amount of heat to dissipate.
If you’re unsure, our team can identify your wall type by examining the brickwork pattern during a free survey.
Does external insulation really stop damp and mould?
Absolutely. High-performance EWI moves the "dew point" to the outside of the wall.
This eliminates cold surfaces where condensation forms, effectively preventing the multiplication of bacteria and fungi.
Your home will be warmer, drier, and much healthier.
Will I need to leave my home during the installation?
No. All works are carried out on the exterior of the property.
There is minimal disruption to your daily life, and there is absolutely no need to relocate while we transform your home's thermal efficiency.
How long does the EWI installation process take?
The process is weather-dependent, as EWI is best installed in dry conditions to ensure materials adhere correctly.
Typically, a project takes between 2 to 4 weeks. We provide a specific timeframe during our initial consultation.
What is the difference between Grey EPS and Mineral Wool?
Grey EPS (Graphite Polystyrene) is the most cost-effective choice with high thermal retention.
Mineral Wool is a premium, natural product made from volcanic rock; it is non-combustible (A1 Fire Rated) and offers superior breathability, making it ideal for older "breathing" constructions.
Do I need to prepare my walls before the installers arrive?
For the best results, walls should be cleaned of dust and loose material.
However, part of our professional service includes a thorough assessment and preparation of the surface to ensure the insulation materials bond perfectly to your specific wall type.
Will EWI drastically change the look of my property?
It’s more of a refreshment than a radical change, though it can completely modernise an older building.
We offer a wide variety of Silicone Render colours and finishes, allowing you to either replicate the original look or create a brand-new aesthetic for your home.
How much can I actually save on energy bills?
By creating a high-performance thermal envelope, EWI can reduce your heating demand by up to 40% annually.
In the current energy climate, this translates to significant financial savings every year for decades to come.
Do I need planning permission for insulation work?
In most cases, EWI falls under "Permitted Development."
However, if your property is in a conservation area or the aesthetic change is significant, permission may be needed.
We provide expert guidance and help you navigate these local requirements.
Can EWI be installed on non-traditional constructions?
Yes. EWI is compatible with a wide array of property types, including many non-traditional constructions.
It is often the single most effective improvement measure you can take to upgrade the EPC rating of such homes.
What exactly is the "25-Year Guarantee"?
A 25-year insurance-backed guarantee backs every system we install.
This covers both the premium materials and our expert workmanship, ensuring your investment is protected long-term.
Does the insulation require any maintenance?
Our premium silicone renders are self-cleaning and weather-resistant, meaning they require very little maintenance.
The system is designed to be breathable and durable, preventing cracks and keeping your facade looking fresh for years without repainting.
How it Works
How External Wall Insulation is Installed, Step by Step
From the first survey to handing over your guarantee - here is what happens on site, and how long each stage takes.

Free Consultation
We visit your property to measure, discuss your needs, and provide a transparent, no-obligation quote. No hidden costs.
Usually within 7 days of your enquiry

Design & Prep
You choose your perfect colour and finish. We set up safely, carefully protecting your windows, doors, and garden.
Quote provided in 3-7 days;
work starts 2-4 weeks after sign-off

Expert Installation
Our TrustMark registered team installs the insulation and render system, typically over 2 to 4 weeks, with minimal disruption to your daily life.
Typically 2-4 weeks;
up to 20 working days for larger detached homes

Final Sign-Off
We leave your property spotless. We hand over the 25-year guarantee only when you are 100% satisfied with the result.
Immediate upon project completion
We also cover areas near Bix
Our team serves homeowners across the Midlands and Greater London.
Get Your Free Quote
Leave your details and we'll get back to you within one working day, usually the same day.

Phone


Address
Unit L, 34 Bayton Rd, Exhall, Coventry, CV7 9EJ, United Kingdom.
No hard sell. We'll arrange a survey at a time that suits you, and
you'll get a fixed written quote with no obligation.
No hard sell. We'll arrange a survey at a time that suits you, and
you'll get a fixed written quote with no obligation.

Phone


Address
Unit L, 34 Bayton Rd, Exhall, Coventry, CV7 9EJ, United Kingdom.




