Cosy Homes London
Home improvements and energy upgrades, made simple, designed around you and your home.
Our services
Whole-home energy efficiency solutions
At Cosy Homes London, we make it easy to improve your home’s comfort, efficiency, and value with expert guidance every step of the way.
Home energy assessments
A professional retrofit survey to identify where your home can save energy and cut costs.
Whole house plans
A long term roadmap to help you prioritise and phase upgrades.
Specification & coordination
Tailored improvement plans managed by our Retrofit Coordinators.
Quality assured installations
We only work with trusted, vetted installers from our curated membership framework and oversee all work for safety, performance, and compliance.
Customer care
Personal support from start to finish, including advice on funding, quotes, and aftercare.
Helping London homeowners
Why choose us
We believe great retrofit starts with clarity, not complexity.
Cosy Homes London provides expert retrofit plans created by qualified Retrofit Coordinators, ensuring your home upgrades are safe, efficient, and built for long-term comfort. From better insulation to full energy retrofits, we make every step simple from first chat to final sign-off.
Key benefits
- Tailored guidance for your home and goals
- Vetted local professionals you can trust
- Transparent pricing with no hidden costs
- Powered by RetrofitWorks’ not-for-profit network
Plan to a warmer, more efficient home
Our process helps you understand exactly what to improve, when to do it, and how each upgrade fits together for maximum comfort and savings.
Process overview
- 01
- Check
Whole house assessment
A qualified Retrofit Assessor surveys your home to identify where energy is being lost and which improvements will have the biggest impact.
- 02
- Create
Personalised retrofit plan
Your Retrofit Coordinator creates a tailored roadmap showing which measures to prioritise now and what to plan for later complete with cost and saving estimates.
- 03
- Upgrade
Relax while we upgrade your home
We connect you with vetted contractors from our trusted RetrofitWorks network and oversee every stage to ensure quality, safety and peace of mind.
Looking for more information?
Find quick answers in our FAQ section.
Powered by RetrofitWorks
Expert support you can rely on for every upgrade
Experience you can trust
Cosy Homes London is powered by RetrofitWorks, the UK’s leading not-for-profit cooperative dedicated to making homes across the country warmer, greener, and more energy-efficient.
Since 2012, RetrofitWorks has helped thousands of homeowners through trusted local professionals, delivering projects built on quality, transparency, and collaboration. When you choose Cosy Homes London, you’re backed by a network of vetted installers, coordinators, and energy experts working together to get retrofit right.
Frequently asked Questions!
We know every home, and every retrofit journey is unique. Here are some of the most common questions homeowners ask before getting started:
1. I’ve heard heat pumps only work in modern, well - insulated homes. Is this true?
No, if done properly, heat pumps can be installed in all sorts of homes, but it’s true that the more energy-efficient your home is, the more efficiently your heat pump will run and the lower your energy bills will be. That’s why we recommend that you install as many insulation and airtightness improvements as your budget will allow before installing a heat pump. You may also need to replace some of your radiators to compensate for the fact that the water circulating in a heat pump system is cooler than from a gas boiler (but still warm enough to heat your home). Our heat pump installer will assess the radiator upgrades required and include these in their final quote.
2. What is a Retrofit Assessor?
No, if done pA Retrofit Assessor is a qualified expert who carries out the crucial initial survey of a home, forming the basis for the Whole House Retrofit Plan.
The Assessor meticulously gathers comprehensive information about the home and passes it to the Retrofit Coordinator. This assessment includes:
• The home's current energy performance.
• Details of ventilation.
• The overall condition of the home, noting any structural, or dampness issues.
• Any historic features.
A thorough Retrofit Assessment is an essential first step in improving a home's energy efficiency.
3. What is a Retrofit Coordinator?
The Retrofit Coordinator plays a central role throughout home retrofit projects. Their work begins with analysing the Assessor's data to develop the Whole House Retrofit Plan and concludes with oversight and sign-off of the installed energy efficiency measures.
At Cosy Homes London, the Coordinator also writes the technical specification for proposed improvements and gathers and approves quotes from our fully vetted member-installers.
This role is essential because it provides homeowners with:
• Impartial, evidence-based recommendations on the costs and benefits of improvements.
• Pragmatic advice on the optimal installation order.
• A holistic, whole-home strategy prioritizing a 'fabric-first' approach, specifying appropriate materials and technologies, and ensuring good ventilation.
• Reassurance that contractors quote for and install the specified materials.
• Confirmation that all improvements are installed competently and to a high standard.
4. I’ve heard stories about problems with cavity wall insulation in the news. Should I avoid insulating my cavity walls?
No, but you should make sure you use a competent, responsible installer who will do the job right. Most of the issues relate to dampness issues caused by installing cavity wall insulation in the wrong location or with inappropriate materials.
One issue is exposed locations where wind-driven rain hits one side of the house. Our installers will check your location to ensure it is suitable for cavity wall insulation.
Another issue is cavities that are unsuitable for insulation, either because it is too narrow or because it is filled with materials such as mortar and rubble. Our installers will check the cavities in your walls to ensure they are suitable for insulation.
A final issue is inappropriate materials that wick moisture from the outer leaf of the wall, which is exposed to the elements, to the inner leaf, which should remain dry. Our installers will only use appropriate materials.
5. I’ve also heard about issues with solid wall insulation. Does this mean solid wall insulation is a bad idea?
Again, no; but it is important to use a Retrofit Coordinator with experience of working on older homes and installers who know which materials to use and, just as importantly, have a proven track record of installing them.
Some of the issues that have been reported in the retrofit industry: Use of inappropriate insulation systems on traditional solid walls. Solid walls are designed to ‘breathe’ – to allow water vapour to move freely. Problems tend to arise when impermeable materials (e.g., insulation, plaster, render) are used, trapping moisture inside walls.
Poor design or installation of insulation systems. Specific issues can include failure to protect the insulation system from the elements, e.g. allowing rainwater to get into or behind the insulation. Insulation of damp walls. If walls have existing dampness issues, it’s important to fix them at source with an appropriate solution and allow the walls adequate time to dry out before installing insulation. Hiding the problem behind new layers is never a good idea.
Problems caused by inadequate ventilation. Many homes, particularly older ones, have an inadequate ventilation system but are draughty, and these two factors have cancelled each other out. When homes are insulated or made more airtight, this inadequate ventilation can become a problem, leading to issues like high humidity, poor air quality, condensation, mould, health issues like asthma and allergies, and even structural issues like dry or wet rot. This is why it is essential to include a ventilation upgrade when installing energy efficiency measures.
6. What is the vetting process for your trusted contractors and suppliers?
Contractors and suppliers who work on Cosy Homes London projects have to first become members of the RetrofitWorks cooperative. This means they have been vetted through their application process, are members of the national quality assurance schemes TrustMark (www.trustmark.org.uk) and MCS (https://mcscertified.com), and are being supported by the RetrofitWorks team and network.
Ready to take the first step?
Start your journey to a cosier more efficient home
Fill out the quick form below, and a member of our team will get in touch with information on how the service works and the next steps.