Green Homes Grant: What does it cover?

Home » Home » Green Homes Grant: What does it cover?

The Green Homes Grant has closed to new applicants as of March 31, 2021. Read here to learn about what happened to the green homes grant and how the government failed to deliver on their promises to homeowners.

The Green Homes Grant is a government scheme launched in September 2020 to help homeowners and landlords cover certain energy efficiency home improvements. Around 600,000 homes are expected to benefit from the grant, which could lead to energy bill savings of up £600 a year for some.

The scheme was set to run until 31 March 2022 but has been cut a year short. Under the scheme grants are issued as vouchers of up to £5,000 – or £10,000 if you receive certain benefits.

Who can get the Green Homes Grant?

The Green Homes Grant is available for homeowners and landlords in England. This includes owner-occupiers, social and private landlords and park homeowners, though new-build homes aren’t eligible.

What energy efficiency upgrades can you get on the Green Homes Grant? 

Home improvements on the Green Homes Grant are split into ‘primary’ and ‘secondary’ measures. In this article, we’ll break down each of these measures, what work is included under them and how much this could potentially cost. For our price estimates, we have used a three-bedroom house in the south of England with average energy consumption. Your own costs may vary, depending on your personal circumstances.

Green Homes Grant: Primary Measures

To qualify for the Green Homes Grant, you must install either insulation or low-carbon heating, known as ‘primary measures’ under the scheme.


Cavity wall insulation

If your home was built between 1920 and 1995, it is likely to have walls made up of two layers with an uninsulated gap in between. This gap is known as the cavity and can often be filled with mineral wool, polystyrene beads or foam insulation to make your home more energy-efficient and cut your heating bills.

How much does it cost? Around £1000

How much could I save? £195 – £240 a year

Solid wall insulation

Most homes built before the 1920s are likely to have solid walls without a cavity. This can also be the case with some newer houses too. A layer of insulation material can be added to the inside or outside surface of your wall to stop heat from escaping.

How much does it cost? Around £1000

How much could I save? £195 – £240 a year

Under-floor insulation for a solid floor

Although not the most straightforward energy efficiency improvement on this list, adding insulation to a solid ground floor made of concrete slabs, flagstones, quarry tiles or similar can help ensure your whole house stays warm. There are two common ways to do this:

1. Adding insulation board on the existing floor followed by a layer of boarding to create a new floor level. As the floor will now be higher, you may have to adjust skirting boards, doors and, potentially, some electrical sockets and plumbing.

2. Digging up the existing floor and adding a layer of insulation underneath, before relaying the floor.

How much does it cost? Around £5000

How much could I save? £55 – £70 a year

Under-floor insulation for a suspended floor

If your home has a suspended wooden ground floor, you can install a layer of mineral wool, rigid boards or foam insulation beneath to reduce heat loss. This is particularly effective if you already have loft and wall insulation installed.

Before any work can be done, you should contact a professional to carry out an expectation to ensure there is no damp, rot or insect damage. If there is, this should be repaired before commencing any insulation work.

How much does it cost? Around £520-£1,300

How much could I save? £55 – £70 a year

Loft insulation

Adding an extra layer of wool insulation to your loft is one of the quickest and easiest ways to help keep your home warm and bring down your energy bills. This is something that can be carried out by yourself or a professional.

How much does it cost? Around £225

How much could I save? £25 – £55 a year

Flat roof insulation

Most houses built before 2000 could benefit from adding extra insulation to any flat roof above a heated room in order to save energy and money. Adding insulation to a flat roof will usually require removing or replacing part of the existing structure.

How much does it cost? £560-700

Room in roof insulation

Roof rooms can lose heat and waste energy very easily if not properly insulated. To keep a roof room warm you’ll need to insulate every surface between the inside and outside of the home. Insulating a loft room usually requires both mineral wool and a rigid material for the roof that won’t sag, such as a high-performance foam insulation board.

How much does it cost? £1500 – £2700

How much could I save? £150 a year

Insulating a park home

Park homes can be among the least energy-efficient types of property, due to their poor insulation. This, in turn, can lead to spending a lot more on energy. However, there are three types of improvements for park homes available on the Green Homes Grant:

  • Wall insulation
  • Roof insulation
  • Underfloor insulation

Low carbon heat

Air source heat pump

An air-source heat pump is a low-carbon heating system which uses electricity to take heat from the outside air and upgrades it to a higher temperature so it can be used to heat your home. This is a good boiler alternative for well-insulated homes without gas.

As an air source heat pump uses electricity, it is not free to use or zero-carbon. However, it produces more energy as heat than it uses as electricity, so it can be a cheap, low carbon heating option for your home. 

How much does it cost? £6000 – £11000

Ground source heat pump

A ground source heat pump is another low carbon heating alternative to a gas or oil boiler. Heat from the ground is absorbed into a working fluid which passes through a compressor to bring it to a higher temperature. 

Ground source heat pumps are not free to use or zero carbon, as they require electricity to run. However, they are far more energy-efficient than a traditional boiler. Ground source heat pumps are suitable for homes with a large garden or similar area due to the pipework that they require. 

How much does it cost? £10000 – £25000

Solar thermal panels

Solar thermal panels are used to source free hot water from the sun and can be installed in homes with a regular boiler and hot water cylinder. It is also possible to fit solar thermal panels for use with a combi boiler, though this is usually a somewhat more difficult process.

The Green Homes Grant can be used to finance the installation of both liquid flat plate and evacuated tubes collector solar panels.

How much does it cost? £10000 – £25000

How much could I save? £255 – £265 a year

Biomass boiler

Biomass boilers burn wood pellets, chips or logs to either provide heating in a single room or run your central heating and hot water in place of a conventional gas or oil boiler. A biomass boiler could be suitable for larger buildings which are difficult to insulate.

Can I get a new gas or oil boiler on the Green Homes Grant?While you are unable to receive funding for a traditional boiler through the Green Homes Grant, some energy-efficient heating alternatives are. Replacing your gas or oil boiler with an air source heat pump, ground source heat pump or a biomass boiler through the scheme could lower your carbon footprint and significantly cut your heating bills.

Green Homes Grant Secondary Measures

Provided you’ve installed at least one of the primary measures through the Green Homes Grant, your voucher can also be used to help cover the cost of one of the following ‘secondary’ measures, as long as its cost doesn’t exceed that of any of your primary measures. 

Secondary measures come under two categories on the Green Homes Grant:

  1. Windows and doors
  2. Heating controls and insulation

Windows and doors

Draught proofing

Sealing the openings around your doors and windows is an easy way to keep warm air in and cold draughts out. This can also help cut your energy bills as you won’t need to use as much energy to heat your home in the first place. 

How much does it cost? Around £100
How much could I save?  £20 – £30 a year

Double or triple glazing (where replacing single glazing)

Replacing old single-glazed windows with double or triple glazing is a surefire way to improve the energy efficiency of your home and reduce your carbon footprint. Single glazing makes the home more expensive to heat and older windows may even let draughts in while allowing heat to escape.

Double and triple-glazed windows contain a gap between the panes of glass that stops heat escaping so easily, while some may even contain a gas between the panes or a special coating, both of which provide further insulation.

How much does it cost? Around £4,900
How much could I save? £75 – £105

Secondary glazing (in addition to single glazing)

A cheaper alternative to double or triple glazing can be secondary glazing. Adding a secondary window pane to the inside helps cut heat loss by trapping an extra layer of air between the two panes of glass. This has the benefit of not changing the appearance of your windows and can be more effective than just draught-proofing.

Energy-efficient replacement doors (where replacing single glazed or solid doors installed before 2002)

Older outside doors or those made with poor quality materials can fit badly in their frames, letting draughts in and heat escape. Replacing them with insulated, draught-proof alternatives can keep these draughts out and your home warm, significantly increasing the energy efficiency of your home.

How much does it cost? Around £1000
How much could I save? £5 – £10 per year

Heating controls and insulation

Hot water tank thermostat

A hot water tank thermostat ensures your hot water stays at the right temperature, avoiding wasting energy by keeping it hotter than you need. You can also use less fuel by setting the thermostat lower.

Hot water tank thermostat

Hot water tank insulation helps retain the water’s heat, meaning you don’t need to use extra energy (and money!) reheating it. Adding an insulation jacket is one of the cheapest ways to do this.

Heating controls

Heating controls determine when the heating comes on and how warm it gets. If you’re carrying out work on your heating system, it can also be a good opportunity to upgrade your heating controls, as it can often be easier and cheaper to do this at the same time.

Heating controls available on the Green Homes Grant include:

  • Appliance thermostats
  • Smart heating controls
  • Zone controls
  • Intelligent delayed start thermostat
  • Thermostatic radiator valves

What else do Green Homes Grant vouchers cover?

Green Homes Grant vouchers cover the costs of all labour, materials and VAT. They also include any additional works that are necessary for the installation of the measures listed above.

All work carried out on the Green Homes Grant must be completed by a TrustMark-registered contractor who is participating in the scheme. 

Apply for the Green Homes Grant

Applications for the Green Homes Grant opened in late September 2020 and all work must be completed by March 2021. 

To get a survey and quote for the work, contact a TrustMark-registered installer. Once you’ve agreed on the works, apply online using the government’s Green Homes Grant application service.

If your application is successful, you’ll receive your Green Homes Grant voucher, which can be redeemed once all the terms and conditions of the scheme have been met.

Click here for more stories and others like this.