How to get the best energy retrofit advice for your home

Seeking home energy retrofit advice should be the first port of call for homeowners who are serious about improving their home's energy efficiency. 

It can be confusing to know where to start and how to invest in appropriate, cost-effective updates, and expert advice that's personalised to your home can be an invaluable tool. 

Horror stories about failed insulation causing damp and mould, and resulting in uninhabitable homes, are a stark reminder of what can go wrong with home energy efficiency projects. In 2025, a National Audit Office review found that 92% of homes that were fitted with external wall insulation under the grant-funded schemes ECO4 and GBIS had major technical issues, many of which will require remediation.

From 2027, a new government advice service - the Warm Homes Agency - will offer impartial advice and clear information on home upgrades to consumers.

But where can you find good advice to help you make informed decisions with confidence now? And is it reliable and useful? To find out, we paid for several different professionals to carry out surveys and provide reports and recommendations for a typical Victorian terraced house in London.

We've compared the reports we received, and given our recommendations for homeowners in need of retrofit advice.

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What is retrofit advice and why is it important?

In this context, 'retrofitting' is the process of making changes to an existing property to make it more energy efficient and, therefore, cheaper and greener to run.

To get the best outcome, choosing a reliable installer or tradesperson is key, but it’s equally important to get good professional advice at the outset to ensure that the proposed work is correctly designed and suitable for your home.

Off-the-shelf advice is rarely appropriate, because every home is different. The age of a building, its location, orientation, wall type, construction materials, and state of repair can all affect the type of energy efficiency work that is most suitable and will produce the best results.

Even in a street of seemingly identical houses, there will be variations due to modernisation, extensions, loft conversions, insulation, and the replacement over time of elements such as windows, doors, and heating systems.

Furthermore, every household uses energy differently, according to the number of occupants, how many hours a day they spend at home, temperature preferences, number of baths/showers taken, and other lifestyle variations.

This means that every home needs to be individually assessed, and its thermal properties, energy use and state of repair understood, before recommendations are made to improve its energy efficiency.

Types of retrofit advice

Free advice is available online, and can be a good introduction, but for in-person advice there is a range of professional services to choose from, at various price points. 

We tried out the following types of advice:

1. Free online advice 
2. EPC (Energy Performance Certificate)
3. Retrofit assessment
4. Solar feasibility report
5. Heat pump survey
6. Whole house plan

1. Free online advice

Accessible to everyone, this is a sensible place to start. In our investigation, we tried the government energy efficiency website at www.gov.uk/improve-energy-efficiency, but we also recommend the Which? home energy planning service. This is a good starting point if you’re new to the world of retrofit, as you’ll be introduced to a wide range of options, and you can select many different combinations to compare the costs and benefits. 

• Pros: Free to access; You can do it online anytime; Save/download an action plan to return to later
• Cons: Only as accurate as your EPC and/or the answers you give; Recommendations may not be cost-effective or suitable for your circumstances
• Costs: Free
• In a nutshell: Free online advice is a good start, and will provide you with a list of options to consider. You’ll need to do more work to ascertain which, if any, is most suitable for your home, and get a more accurate assessment of the costs and savings. But it’s free and you don’t need to have an EPC already, so it’s worth checking to get an initial overview of what might be available. 

2. EPC (Energy Performance Certificate) 

The basic entry point for most, though unfortunately we have found them to be unreliable.  

We don’t recommend relying on a commercial EPC for your retrofit journey, as the recommendations are rather generic, and the report itself can be inaccurate. The majority of EPCs are carried out to satisfy legal requirements when a home is put on the market for sale or rent, so their usefulness as a retrofit advice tool is rarely tested. 

• Pros: Inexpensive; Quick; Non-invasive; Easy to book and widely available
• Cons: Accuracy is questionable; Energy costs are based on typical usage rather than your specific household; Recommendations may not be cost effective
• Costs: We paid a local, self-employed Domestic Energy Assessor £68 for an EPC for a four-bedroom house in London. In most cases, an EPC booked online with a commercial assessor will cost less than £150. For some properties, it may be as little as £50.
• In a nutshell:  EPCs are inexpensive, but unreliable. When correct, they may offer helpful recommendations, especially if you haven’t made the most cost-effective improvements to your home yet, such as loft or cavity wall insulation. If low-cost, high-impact measures have already been done, the other recommendations are often very expensive, with long payback times (25+ years), and involve significant disruption to your home.

Read more on EPCs in our guide to how to get an EPC

3. Retrofit assessment

More in-depth than an EPC, and more bespoke to your home's occupants and the way you live, a three-part retrofit report includes an EPC, an Occupancy Assessment that details how energy is used in your home, and a Condition Report that evaluates the building's current state of repair. However, we don’t recommend a commercial retrofit assessment as they are largely aimed at government-funded retrofit schemes and the advice offered to homeowners can be unhelpful and unreliable - we've detailed the shortcomings of our report further down this page.

• Pros: More in-depth and bespoke than an EPC; May identify issues such as damp, mould or condensation
• Cons: Questionable accuracy; Recommendations may not be cost-effective
• Costs: Our retrofit assessment cost £189 from a local Retrofit Assessor operating as a registered company. You can expect to pay up to around £300 for the three-part report.
• In a nutshell: In our investigation, we weren't impressed with the results of the retrofit assessment. In theory, it should have some benefits over an EPC, as it includes an Occupancy Assessment which allows for a tailored calculation of energy use and potential savings based on the current occupants. A Condition Survey will identify other building problems that need to be addressed before installing insulation or doing other improvement works. If you do go ahead, ask for an assessment and advice report that complies with BS 40104.

4. Solar feasibility report

Independent advice for those thinking about installing solar panels. We paid £150 in our investigation, and similar solar surveys are available from community organisations in some areas at around the same price. Some will refund the cost if your home turns out to be unsuitable. 

Although often done remotely – with no home visit – this can be a useful exercise if you’re considering solar panels, as you’ll get an idea of the suitability of your roof, the cost, potential savings, and a proposed system design that you can use to get installer quotes.

• Pros: Relatively inexpensive; Very quick and non-intrusive (no home visit needed); Based on your actual energy use; May be refundable if your home turns out not to be suitable
• Cons: Costs are estimates, so subsequent quotes may vary; No on-site visit, which means unidentified issues such as roof condition or access constraints may result in additional costs down the line
• Costs: We paid £150 for a solar PV feasibility report from a local not-for-profit community enterprise in southeast London. The fee was refundable if the report found our roof to be unsuitable for solar panels.
• In a nutshell: If you’re considering solar PV, or your EPC or another report has recommended it, this may be a good next step to offer a cost/savings estimate and system design. It gives independent advice and support around solar panel installation for your home, rather than relying on installers to advise and quote. The service we used included the option to subsequently submit installer quotes for appraisal. 

Read our solar panel buying advice and more on how much solar panels cost 

5. Heat pump survey

An often refundable first step for anyone considering a heat pump.

• Pros: Quick, free initial online quote; Followed by a thorough technical survey of your home to identify heat-pump suitability, potential issues and solutions; Often a refundable survey fee if your home is unsuitable (we paid £200, which was refunded)
• Cons: A lengthy on-site survey (up to three hours); Not impartial if conducted by an installation company; You won't get advice on other areas
• Costs: Our heat pump survey cost £200 from a large heat pump manufacturer/installer. The fee was refundable if the survey found that our home was unsuitable for the installation of one of their heat pumps. Survey costs generally range from around £200 to £500. Many installers offer an initial free quote, but you will always need a full technical survey, including a heat loss calculation, to receive a final price and system design.
• In a nutshell: If you approach a company about potentially getting a heat pump installed, the first step will be a survey. It's worthwhile if you’re considering a heat pump, as you’ll need a technical survey, including a heat-loss calculation. It also considers planning/noise issues, location of the pump and hot water cylinder, pipework and new/upgraded radiators. If using an installer, look for one with a refundable fee, so you won’t lose out if the company can’t install your heat pump. 

See our introduction to heat pumps and more on air source heat pumps explained

6. Whole house plan

This is by far the most expensive option, but the advice we received was genuinely useful and actionable. The 26-page report we got was a real stand out in our investigation. It considered our priorities and budget, and offered a full range of recommended improvements, with detailed costs and savings and a phased plan for carrying out the works. We also received detailed architectural drawings (floor plans and elevations), a 360° virtual video tour of the property, and a 30-minute follow-up call with the Retrofit Coordinator. Although the price is high, it represents a small percentage of the cost of undertaking an extensive retrofit project, and should help you achieve the best outcome whilst avoiding costly mistakes. 

• Pros: Comprehensive survey and bespoke follow-up report; Clear, phased recommendations based on your priorities; Independent advice; Includes on-going support as you progress
• Cons: By far the most expensive option, so only worth doing if you are serious about investing in retrofit works in your home; Costs are estimates, so actual installation costs may vary
• Costs: We paid £745 to a retrofit consultancy company and received a very comprehensive 26-page report prepared by a Retrofit Coordinator. Similar retrofit plans are available from both commercial and non-profit organisations, ranging in cost from around £500-£1,000. 
• In a nutshell: Recommended if you’re committed to improving your home’s energy efficiency to understand all the options. A very comprehensive report, including a heat-loss calculation, with recommendations tailored to your home, your budget and what you want to achieve. Provides indicative costs, a phased plan and a follow-up call, and often includes ongoing retrofit coordinator support during installation.

Our retrofit research

In August-September 2025, we paid for several different professionals to carry out surveys and provide reports and recommendations for a typical Victorian terraced house in London. 

We found that some of the reports were inaccurate and we wouldn’t recommend them if you’re serious about making your home more energy efficient. Our experiences with a Domestic Energy Assessor (who carried out an Energy Performance Certificate (EPC) assessment) and a Retrofit Assessor were both unsatisfactory, and we had to complain to their respective accreditation schemes about their inaccurate reports.

Even if they are correctly done, the recommendations on an EPC or retrofit report may not be suitable or affordable for your home. That's because they are generated automatically by the reporting software, and you generally won't receive bespoke advice from the assessor personally. However, if you know a reliable professional or have a recommendation from someone you trust, you may find these reports to be a low-cost starting point.

The next level up is a feasibility assessment carried out with a particular technology in mind. Most installers will carry out surveys or feasibility assessments for work such as installing insulation, heat pumps, or solar panels. Note that they may not have the wider knowledge to offer comprehensive advice, and it will not be impartial. If you are already considering improvements, you may like to use an independent energy advice service instead to carry out the initial survey and recommend suitable options. 

The most comprehensive option is a whole house plan conducted by an independent company. This professional advice considers all the options, and takes account of your budget and priorities, whether that's lowering your energy bills, reducing your carbon emissions, or making your home a more comfortable place to live. 

We found that, although it was the most expensive option, at £745 for a four-bedroom house, this type of advice is highly detailed and personalised.

Where to find qualified professionals

Domestic Energy Assessors and Retrofit Assessors must be suitably qualified and accredited. You can find all accredited DEAs, who can provide an EPC for homes in England, Wales or Northern Ireland, online at GOV.UK or at the Scottish EPC Register for properties in Scotland. 

Assessors can also be found through the accreditation scheme with which they are registered. Elmhurst Energy is the largest of these and has a searchable list online. 

DEAs and Retrofit Assessors can also be found on the government-endorsed Trustmark website, as can accredited Retrofit Coordinators. 

An online search may suggest a number of websites offering direct booking for EPCs and other surveys. These sites often advertise low prices and convenient payment options, but always check that the professional you’re booking is properly accredited, and treat reviews with the same caution as you would elsewhere online. An assessor who receives top reviews for prompt arrival and a polite manner does not necessarily deliver accurate reports and recommendations.

The Royal Institution of Chartered Surveyors (RICS) may be able to recommend a suitable surveyor with retrofit experience. Although the organisation is currently exploring opportunities to create a membership pathway for specialists in residential retrofit surveying, there is currently no specific RICS retrofit qualification. RICS home reports – the kind you typically get when buying a property – are not designed to offer advice on energy efficiency improvements.

Finding local retrofit advice in England, Scotland, Wales and Northern Ireland

The government's newly-announced Warm Homes Agency (WHA) is expected to operate at both a national level across the UK and at a local level to support consumers through their home decarbonisation journey, from 2027.

In the meantime, more than 140 local and regional advice services already exist in England alone. Researchers from the University of the West of England (UWE) have mapped the retrofit advice services in England that provide tailored, individual advice to homeowners. 

They include charities, universities, community interest companies (CICs), social enterprises, not-for-profit community enterprises, community groups, community benefit societies, not-for-profit co-operatives, and local authorities, offering services in the following three categories:

1. Advice: Tailored retrofit advice for individual homes.
2. Whole house planning: A service to assess a home and create a comprehensive plan of retrofit measures for households to consider.
3. One-stop shop: A comprehensive retrofit support service, often offering assessments, planning and support through the retrofit process such as identifying tradespeople, project management and financing options.

You can explore the interactive map of advice services in England to find one in your area.

This resource does not include private companies/consultancies, or services that solely provide government-funded support.

In Scotland, Home Energy Scotland  (run by the Energy Saving Trust) offers free advice, while Changeworks currently offers the EcoCosi home retrofit service in Edinburgh, the Lothians and the Borders, with a planned rollout to other areas. 

In Wales, the Welsh Government's Nest programme offers free advice online and over the phone.

For advice in Northern Ireland, the Energy Saving Trust provides advice and also runs the Northern Ireland Sustainable Energy Programme (NISEP) which manages funding for energy efficiency schemes. The NI Housing Executive also offers online advice including a home energy saving tool.