What Is Underfloor Insulation? Best Under Floor Insulation Grant 2023

Insulating the ground floor is an effective way to maintain warmth in your property. Typically, only the ground floor requires insulation. However, underfloor insulation is only sometimes necessary for your floor area if you reside on a higher floor.

Yet, it's essential to consider insulating floors positioned above spaces that aren't heated, like garages, as significant heat loss might occur through them.

Check out our guide on what is underfloor insulation.

What Is Underfloor Insulation And Why Is It Important?

Insulating your ground floor is an effective method to ensure your property remains cosy and warm. Generally, it's only the ground floor that requires insulation. Insulating that space is optional if you're situated on a higher floor.

However, if your floors are situated above spaces that aren't heated, such as garages, you might experience considerable heat loss. In these instances, insulating those floors is prudent to reduce heat dissipation.

By underfloor insulation, you restrict the flow of heat through them. This means your home will feel snugger and warmer in winter and more refreshingly cool in the summer.

If you seal the gaps between the floor and skirting boards, implementing floor insulation can diminish your carbon emissions by roughly 240kg annually and nearly 100 kilograms.

The Energy Saving Trust states that introducing insulation beneath a wooden floor can save around £60 annually. Considering the material costs hovering around £100, the expenses would be recouped in roughly 1.8 years.

Is My Home Suitable For Underfloor Insulation?

Modern homes often have concrete ground floors. While these can be insulated by placing insulation on top, they don't qualify for the scheme. The support is typically available for older properties more prone to suspended timber floors.

If your home has a basement or cellar, you probably possess a suspended floor, where the floorboards lie atop joists. Such floors tend to lose heat more readily. If you notice air or ventilation bricks, it's another sign suggesting you have a suspended floor, which would profit from underfloor insulation.

During the insulation process from below, mineral fibre is unrolled and held in place using netting stapled between the floor joists. A modern method involves the application of spray foam to the bottom of the floorboards.

How To Add Underfloor Insulation?

When insulating suspended timber floors in your home, it's essential to consider three primary aspects:

Thermal Efficiency: This ensures the insulation retains heat effectively.
Moisture Management: The insulation should be able to absorb water vapour during high humidity periods and release it during times of lower humidity, all the while preventing liquid from penetrating.
Air Tightness: The installation should be sealed off from external air, preventing draughts.

To achieve optimal underfloor insulation, you can follow this process:

Start by removing the floorboards to reveal the floor joists. Inspecting for any defective joists and repairing them as necessary is crucial at this stage.
If you have an exposed clay or soil surface beneath, it's a good idea to lay a vapour barrier, reducing the potential for moisture seepage from the ground.
Next, lay an airtightness membrane over the joists. This membrane not only prevents wind washing but also ensures that any residual moisture is allowed to escape, maintaining the floor's health.
For the insulation itself, it's recommended to use high-density materials that won't sag or settle over time.
Materials like treated sheep's wool, wood fibre, or jute insulation, are ideal as they naturally regulate moisture levels, absorbing excess water vapour and releasing it as conditions change.
Once the insulation is in place, add a vapour control layer on top. This layer moderates the movement of water vapour towards the insulation.
Ensure all overlaps are correctly sealed, and all edges, especially where the floor meets walls, are taped securely.
After ensuring everything is in place, you can finally reinstall your floorboards again.

Underfloor Insulation Grants- Why Apply For It?

Under the ECO programme, households with low incomes or those facing challenges affording home heating could be eligible for a complimentary underfloor insulation grant. If you meet the criteria and your home is suitable, you could receive free underfloor insulation.

Here's why you can apply for the floor insulation grant:

Eligibility for the scheme could grant you free underfloor insulation.
Significant savings on heating bills with underfloor insulation.
Experience a cosier home without the heating cost concerns.
Boost your home's potential resale value.
Take advantage of the grants while they last.

Who Is Eligible For Underfloor Insulation Grants?

If your home was built post-1980, you might not qualify for an underfloor insulation grant since most homes from this period have concrete floors instead of timber.

However, exceptions apply if your home has a basement cellar or is constructed on an incline.

Eligibility for free underfloor insulation grants may depend on your household income being £31,000 or below or if your property receives certain benefits. The qualifying benefits are:

Income-based Jobseekers Allowance (JSA)
Income-related Employment & Support Allowance (ESA)
Income Support (IS)
Pension Credit Guarantee Credit
Working Tax Credit (WTC)
Child Tax Credits (CTC)
Universal Credit (UC)
Housing Benefit (a new addition under ECO4)
Pension Credit Savings Credit (also a new addition under ECO4)

Additionally, to be eligible, you should:

Be the homeowner living in the property.
Reside in England, Scotland, or Wales.
Have a home heated by gas.

If your ground floor was insulated in the past, you might qualify for an upgrade to the current standards.

A consultation with one of our experts can provide clarity on this matter.

Adhering to Building Standards

All floor insulation tasks we undertake for your property will strictly follow the relevant building codes for your location. For instance, the stipulated U-value for floors in England and Wales is 0.25 W/m2K. This U-value indicates the rate at which heat passes through the floor.

Achieving this standard typically demands at least 70mm of high-grade foam insulation or 150mm of mineral wool. However, the exact requirements might differ depending on the individual property.

How Much Will You Save?

Investing in top-notch underfloor insulation installed by experts could range from £300 to £1200. However, with the availability of underfloor insulation grants, there's a chance you could receive this service at no cost. Moreover, once installed, underfloor insulation offers consistent annual energy savings.

Here are the average annual energy savings statistics provided by the Energy Saving Trust, depending on your type of home (these figures are based on fuel prices as of October 2022):

Detached house: £190 savings
Semi-detached house: £130 savings
Mid-terraced house: £85 savings
Bungalow: £190 savings

These figures underscore the cost-effectiveness of underfloor insulation in the long run.