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Home improvements guide

UK homeowners’ two biggest bugbears are lack of storage and cold rooms, with 40% of us worried that we can’t keep our homes warm in winter. Are you one of them?

When homeowners make home improvements like a loft conversion or an extension, they generally don't make energy efficiency upgrades beyond those required by building regulations. Installing energy efficiency upgrades, such as insulation or draught-proofing, will not only make your home warmer, but also help alleviate causes of damp and mould, and lower your energy bills.

Making home energy efficiency upgrades in parallel with work being undertaken on your home improvement could be more cost effective and less hassle than employing a further tradesperson to carry them out at a later date. The following guide proposes some simple changes to better plan ahead and offer advice on which jobs can be easily combined.

wind and solar energy with energy ratings on a measure
Jump to: Insulation, Lighting, Renewable energyHeating upgrades, Windows and doors, Kitchens, Bathrooms, Compliance


Make sure your extension is insulated to the standards stipulated by Building Regulations in England and Wales, and Building Standards in Scotland. Consider requesting a quote from your builder to arrange for the rest of your home to be insulated as well. If your home has cavity walls, a layer of insulation can be blown into the cavity.

If you have solid walls (usually homes built before 1920), you can have either internal or external insulation completed. Applying external insulation at the same time as your extension would ensure the exterior finish to the main building matches the extension, improving the aesthetic of your home. 

External insulation will also make those cold rooms in your home warmer and, so long as sufficient ventilation is maintained, it can help alleviate many causes of damp and mould. Furthermore, solid wall insulation could save around £225 a year from the heating bills of a typical gas-fuelled semi-detached home. Savings could be significantly higher in detached properties, around £375 per year in a typical gas-fuelled detached home. 

Read our comprehensive overview on the many ways your home's insulation can be improved.

workman fitting wall insulation


Lighting accounts for 15 per cent of a typical household’s electricity bill. So, it can be a good time to consider the most efficient lighting options when making alterations to your home. 

LEDs are the most efficient light bulb on the market and have made significant advancements since their early days of low quality lighting. They are available with varying degrees of brightness, colours, and ‘colour temperatures’ – from warm white to cool white in appearance – and can suit almost all light fittings. Although the cost of bulbs is coming down, as highlighted in our blog post, it can sometimes appear prohibitive, so consider the most used lights throughout your home as a first step. 

Your tradesperson must install low energy light fittings under current Building Regulations as part of the works they undertake and this would be something they can advise on for the remainder of your home. Read our energy efficient lighting blog series to learn more.

You can put your energy efficient lighting knowledge to the test here, and search for LED bulbs for your home here.

hand changing a regular light bulb for an led bulb 

Renewable energy

If your home improvement work requires scaffolding, such as a loft conversion, this would be an ideal time to install solar panels. Scaffolding is a significant part of the solar installation costs, so combining it with other works could make them much more cost-effective. Solar panels are most effective on south-facing roofs at a pitch of around 30 degrees.

There are various other factors to consider when thinking about whether your home set up works and how best to maximise the installation. For more information on installing renewable energy system at home, see here 

  solar panel installer with drill installing solar panels

Heating upgrades

Extending the size of a home often requires improvements to your heating system and installation of new radiators or under-floor heating. As a larger area is being heated, a more powerful boiler will likely be required so consider upgrading to a more efficient boiler. This is particularly worthwhile if your current boiler is over 12 years old, with newer models significantly cheaper to run than their older equivalents.

Boilers are often located in kitchens and it’s important to plan ahead – especially if you’re thinking of investing heavily in a new kitchen. If you have an older boiler, for example, and you build your new kitchen around it, you might then find that that the boiler needs replacing in a few years’ time. An engineer might need to move kitchen units around to accommodate your new boiler which could impact on the aesthetics. It’s important to weigh up the pros and cons, and if your boiler is an old inefficient model, it might be wise to replace your boiler at the same time as getting your new kitchen fitted.


man's hands setting the temperature on an electric boiler

Avoid short-cuts such as using electric heaters which many people do to avoid tampering with their existing heating system. Electricity is the most expensive heating fuel – in the long run you’d be better to upgrade your heating system and its controls.


Many householders leave their heating on constantly at a low temperature believing this is the best way to keep their home warm. This results in wasting heat and money when you're out, and not being warm enough when you're home. Heating controls enable you to control your heating so that you are warm and cosy exactly when you want to be. Connecting new heating controls to your system allow you to more effectively control how and when different areas of your home are heated. Such devices could provide big savings on your energy bills, particularly when you’re increasing the size of your home. Thermostatic valves on radiators are essential, giving you manual control over how much heat each room requires and minimising waste.

Whereas traditional heating controls bring flexibility, allowing programmable running time to fit your lifestyle, the latest generation of ‘smart’ thermostats offer even more flexibility. In addition to offering the full range of timing controls, you can remotely control your heating from your tablet, smartphone or desktop, changing temperature, timing and even, with some technologies, ensure you have hot water ready for your return home.

With today’s hectic lifestyles and unpredictable work life, smart thermostats also eliminate worries when you’re away for extended periods – switch heating off if you forget, or on when cold weather is on its way. 

Installing a room thermostat, a programmer and thermostatic radiator valves and using these controls efficiently could save you around £80 a year*. Detailed information on potential savings you could make can be found on our Thermostats and Controls page.

smart home climate control system

*If you didn't have any controls beforehand.


When planning your heating, think about the layout of the new room. Try to keep radiators away from where you plan to position large items of furniture such as sofas or sideboards, which can restrict warm air circulation. And consider whether you need to heat your extension (e.g. a conservatory or vestibule), but either way make sure that there is good draught-proofing between the heated parts of your home and the extension to avoid heat from your home escaping into it.

Professional draught-proofing of windows, doors and blocking cracks in floors and skirting boards can cost around £200 for materials but could save around £35 a year on energy bills and make for a cosier home. By following our useful guide, DIY draught proofing can be carried out relatively easily and inexpensively.

Windows and doors

When installing new windows or external doors, they will have to comply with minimum Building Regulations. However, it’s worth going beyond the minimum and installing the most efficient ones you can afford. As well as making sure your doors are well draught-proofed, you could consider getting triple glazing rather than double glazing which also includes the benefit of reducing sound from outside noise should you live in a busy location.

Installing A++ rated double glazing in an entirely single-glazed house could save around £105 per year off heating bills of a typical semi-detached home. Read more here

wooden frame lead windows


If you're having a new kitchen installed and purchasing new appliances, choosing more efficient appliances will help save on energy bills.

Watch out video for tips:


To help consumers looking to make the best choice, with low running costs and environmental considerations in mind, the Energy Saving Trust have been in charge of the Topten UK products list since 2015, an independent guide set up to highlight the leading products for energy efficiency. The list is based on comprehensive market reports to define specific criteria around what makes a top ten product. It also takes into account a range of models and costs to cover different preferences and budgets whilst always pointing consumers towards an efficient product. The list have to be updated at least every six months and tend to be based on trends where different product types are refreshed at specific times of the year.


If you’re renovating your bathroom, make sure to purchase energy efficient to help reduce water usage throughout the home. There are many different styles of shower head to choose from which are designed to aerate the water more thereby reducing water usage without a negative impact on your shower experience. A water efficient shower head could save a four person household (e.g. a family of four or even a shared student flat) around £40 a year on gas for water heating, as well as a further £55 a year on water bills if using a water meter.* You should also look for low-flush toilets – saving at least one litre of water per use.

If you’re adding extra heating to your bathroom, such as a towel rail or underfloor heating, make sure it is installed with easy to use, accessible controls and ask your installer to explain how to use them to allow you to control them better. 

planned renovation of a luxury modern bathroom

*Calculation is based on the assumption that each person takes 8 showers a week and replaces a 9.8 litre per minute shower head with a 7.7 litre per minute water efficient shower head, and the family are charged £2.65 per cubic meter of water used (includes sewage charge).


All works need to comply with Building Regulations in England and Wales or Building Standards in Scotland.

These are minimum standards for design, construction and alterations to buildings. They apply to almost anything which could be considered ‘Building Work’ – this means they cover large projects such as extensions or loft conversions, but also smaller projects like replacing doors or windows, or getting a new boiler.

Both Building Regulations and Building Standards legislate how energy efficient any alterations to your home need to be. This means there is a minimum amount of insulation that needs to be installed in a loft conversion or extension, and there are minimum U-Values – a measure of heat loss – for building elements such as windows and doors.

If you are the owner of the building, it is ultimately your responsibility to ensure the work complies with regulations. If you are employing a builder, you should confirm at the start that they will take responsibility for compliance.    

rainbow of house outlines in energy efficiency colours

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Financial support

Find out about the grants and loans available to support your project in different areas of the UK.

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Tips and advice on energy efficiency

Check out our blogs for up to the minute tips and advice on all aspects of home energy efficiency.

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Stay up to date with the latest ideas and information about home energy efficiency. Our innovations page lists the latest products and service that can help you save energy at home.

Check our innovation page