Question 1

What is external wall insulation?

Accepted Answer

External wall insulation (EWI) involves fixing insulation boards to the outside of your walls, then covering them with a protective render finish. It keeps heat in, reduces energy bills, and transforms your home's appearance.

Question 2

How much warmer will my home be?

Accepted Answer

Significantly warmer. Customers typically describe the change as dramatic: walls that were cold to touch become warm, rooms that never heated properly become comfortable, and many report a 25-40% reduction in heating costs.

Question 3

Will external wall insulation stop condensation?

Accepted Answer

Yes, usually. Condensation happens when warm air meets cold walls. When your walls are properly insulated, they stay warm on the inside, so condensation stops forming. This also helps prevent the mould that comes with condensation.

Question 4

Can I have external wall insulation if I have cavity walls?

Accepted Answer

Yes. External insulation can be added to solid walls, cavity walls, and even walls that already have cavity insulation. It adds an extra thermal layer and completely transforms the appearance.

Question 5

Will it make my rooms smaller?

Accepted Answer

No. Unlike internal insulation, external wall insulation is added to the outside of your home, so your internal room sizes stay exactly the same.

Question 6

How long does external wall insulation last?

Accepted Answer

Properly installed external wall insulation using quality materials typically lasts 25-30 years or more. The insulation itself does not usually degrade; the render finish may need attention eventually, but we are talking in decades rather than years.

Question 7

Do I need planning permission?

Accepted Answer

Usually not. External wall insulation is typically permitted development. However, if you are in a conservation area, have a listed building, or your property has specific restrictions, you may need approval. We advise on this during your survey.

Question 8

What is K Rend?

Accepted Answer

K Rend is a brand of silicone render made by Kilwaughter Minerals. It is one of the UK's most popular external render products: hydrophobic, self-cleaning, breathable, and colour stable.

Question 9

Why do you use K Rend?

Accepted Answer

It is a proven, high-quality product that performs brilliantly on the older Midlands homes we work on. It offers excellent water resistance, good breathability, a wide colour range, and is backed by a 25-year manufacturer guarantee.

Question 10

What K Rend colours are available?

Accepted Answer

There are dozens of options, including whites, greys, creams, naturals, and more. We bring samples to your survey so you can see real options against your property. Grey is currently the most popular choice.

Question 11

Can you match my neighbour's K Rend colour?

Accepted Answer

Usually yes. If you know the colour name, we can match it exactly. If not, we can often identify it from a sample or photo.

Question 12

How long does K Rend last?

Accepted Answer

K Rend typically lasts 25 years or more with minimal maintenance. It is through-coloured, so it will not need painting, and its self-cleaning properties help keep it looking good.

Question 13

Does K Rend need maintenance?

Accepted Answer

Very little. There is no painting required. An occasional wash with a hose can keep it looking fresh, but even that is often unnecessary thanks to its self-cleaning properties.

Question 14

How much does external wall insulation cost?

Accepted Answer

It depends on property size, complexity, access, and condition. Typical ranges are terraced £5,000-8,000, semi-detached £8,000-12,000, and detached £10,000-16,000 or more. We provide accurate quotes after surveying your specific property.

Question 15

Why don't you publish exact prices?

Accepted Answer

Because every property is different. A typical semi can vary hugely in wall area, complexity, and condition. We do not want to mislead you with from-prices that do not reflect reality. A survey gives you an accurate quote for your home.

Question 16

Do you offer payment plans?

Accepted Answer

We can discuss payment terms that work for you. Typically there is a deposit on acceptance and the balance is paid on completion, but we are flexible.

Question 17

Are there any hidden costs?

Accepted Answer

No. Our quotes include everything: scaffolding, materials, labour, and all finishing details. The price we quote is the price you pay.

Question 18

Is it worth getting external wall insulation?

Accepted Answer

For most owners of cold, solid-wall homes, yes. Energy savings can often cover the cost within 10-15 years, and you also get immediate benefits such as a warmer home, less condensation, and a transformed appearance.

Question 19

What happens during the survey?

Accepted Answer

We visit your property, assess your walls, discuss your requirements, show you colour samples, and answer your questions. It usually takes about 30-45 minutes. There is no charge and no obligation.

Question 20

How quickly can you start?

Accepted Answer

Usually within 2-4 weeks of accepting a quote, depending on our schedule.

Question 21

How long does installation take?

Accepted Answer

An average property typically takes 2-3 weeks. Larger or more complex properties may take longer.

Question 22

Can I stay in my home during the work?

Accepted Answer

Yes, absolutely. The work is entirely external. There will be scaffolding and some noise, but you can live normally in the property throughout.

Question 23

What about my garden?

Accepted Answer

Scaffolding has to stand somewhere, so there is some impact. We take care to protect plants and surfaces, and any minor disruption is temporary.

Question 24

What happens to gutters, downpipes, lights, and similar fittings?

Accepted Answer

We remove them before starting and refit them, or replace them if needed, once the render is complete. It is all included in our quote.

Question 25

Do you work in winter?

Accepted Answer

Yes, although very cold or wet weather can affect render application. We schedule work appropriately and keep you informed if weather causes delays.

Question 26

How long have you been in business?

Accepted Answer

Since 1985, which means more than 40 years of insulating Midlands homes.

Question 27

Are you a local company?

Accepted Answer

Yes. We are based in Nuneaton and serve Coventry, Birmingham, and the wider Midlands. We are not a national franchise; we are a local family business.

Question 28

Do you use subcontractors?

Accepted Answer

No. Everyone who works on your property is employed by Rockwarm. We do not subcontract installation work.

Question 29

Are you accredited?

Accepted Answer

Yes. We are TrustMark registered and BBA certified. We also work with housing associations and energy providers as approved contractors.

Question 30

Why don't you do ECO4 or grant schemes?

Accepted Answer

We believe grant schemes often give homeowners a worse deal: inflated costs, lower-spec materials, no choice of installer, and longer delays. We would rather give you a fair price for excellent work completed quickly. Read more about grants vs private.

Question 31

What areas do you cover?

Accepted Answer

Coventry, Nuneaton, Birmingham, and the wider Midlands, roughly a 30-mile radius from our Nuneaton base. If you are unsure whether we cover your area, just ask.

Question 32

What if something goes wrong after installation?

Accepted Answer

Call us. We stand behind our work and address any issues. We have been here for decades and we are not going anywhere.

Question 33

What insulation do you use?

Accepted Answer

We use Rockwool stone wool insulation as standard. It is breathable, fireproof, acoustically insulating, and better suited to older solid-wall homes than cheaper polystyrene systems.

Question 34

Why Rockwool instead of polystyrene?

Accepted Answer

Breathability is the main reason. Older homes need walls that can release moisture, and Rockwool allows this while polystyrene does not. Rockwool is also A1 fire rated and provides acoustic insulation. Learn more.

Question 35

What thickness insulation do you use?

Accepted Answer

Typically 100-150mm, depending on your property and requirements. We recommend the most appropriate specification during your survey.

Question 36

What guarantee do I get?

Accepted Answer

K Rend provides a 25-year manufacturer guarantee on the render. We also provide our own workmanship guarantee, and as a long-established local business we are here to honour it.

Frequently asked questions

Frequently Asked Questions

About External Wall Insulation

About K Rend

Costs & Pricing

The Process

About Rockwarm

Materials & Quality

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