Cavity Wall Insulation Grant

Tired of drafty walls and rising heating bills? No worries, and transforming your home's energy efficiency with cavity wall insulation. Government grants are available that cover 100% cost to help eligible households. Enjoy your living in warmer winters with lower energy bills, and less CO2 emission—all at ZERO cost.

A Brief About Insulating Your Cavity Walls

Before installing underfloor insulation, proper preparation is key. Start by lifting the floorboards to expose the joists—the wooden beams supporting your floor. Inspect them carefully for any damage or decay and carry out repairs as needed. If the joists rest directly on exposed soil or clay, it's essential to lay a vapour barrier. This protective layer stops ground moisture from rising into your home, helping prevent damp issues and ensuring your insulation performs effectively. At Envirofit, we make sure every step is done right for long-lasting comfort and efficiency.

Insulation Materials Used Between Cavity Walls

Cavity wall insulation is typically done from the outside, using professional techniques. At Envirofit, registered specialists drill small holes (18–25mm deep) into your home’s exterior walls. Through these holes, they inject high-performance insulation—often polystyrene beads—into the cavity. Once filled, the holes are sealed to maintain your home’s appearance. This process isn’t a DIY job—it requires trained professionals like Envirofit to ensure safety, precision, and effectiveness. For a standard home with easy wall access, the entire procedure usually takes around two hours, with minimal disruption to your daily life.

 
 
 

Energy Savings

Installation costs for underfloor insulation depend on the size of your home. Whether you live in a large house or a small flat, you can usually recover the investment within five years through reduced energy bills. To cut down on expenses, consider aligning the installation with other home improvement projects or insulating only the most heat-losing areas instead of the entire property.

 
 
 

Government Schemes Offering Cavity Wall Insulation Grants

ECO4 Scheme

Envirofit offers 100% funding for cavity wall insulation, prioritizing low-income households.

Eligibility includes:

  • Receiving benefits such as: Universal Credit, Pension Credit, Job Seeker’s Allowance, ESA, Income Support, Tax Credits
  • Property with uninsulated cavity walls
  • EPC rating of D, E, F, or G

Great British Insulation Scheme

The GBIS grant, supported by Envirofit, covers 100% of both insulation materials and installation costs.

Eligibility includes:

  • Homes with high energy costs
  • Homeowners and private tenants (with landlord consent)
  • No requirement to receive government benefits
  • Council tax band A–D (A–E in Scotland & Wales)
  • EPC rating below D

Benefits of Cavity Wall Insulation Grant

Absolutely Free – With government grants available through Envirofit, you pay nothing for materials or installation. No financial strain, just energy savings.

Reduced Energy Bills – Cut down on heat loss by up to 35% and slash your heating costs by as much as £300 per year.

Warmer, Cosier Home – Enjoy year-round comfort. No more cold floors, just a snug, energy-efficient home.

Improved EPC Rating – Boost your Energy Performance Certificate score, increasing the value and appeal of your property.

Eco-Friendly – Reduce your carbon footprint and join the mission to fight climate change by lowering CO₂ emissions.

Other Eligibility Checklist

  • The external walls are unfilled cavity walls.
  • The cavity is at least 50mm wide and clear of rubble.
  •  The masonry or brickwork is in good condition.
  • Walls aren’t exposed to heavy rain.
  • Your home isn’t at risk of flooding.
  • An installer will survey your house to confirm suitability. If suitable, they can be insulated using mineral wool or polystyrene beads.

Important Precautions

Before installing insulation, it’s crucial to fix any damp issues. If you notice damp patches on internal walls, don’t proceed with insulation—consult a damp prevention specialist first.

In homes with narrow cavities, uneven walls, flood-prone areas, or exposed locations, polyurethane foam insulation may be recommended. Though it comes at a higher cost, it’s incredibly effective. A qualified foam insulation specialist will evaluate and carry out the work if your property is suitable.

If your home shares exterior walls with a neighboring property, a cavity barrier will be installed to ensure the insulation doesn’t affect your neighbour’s structure.

For flats, insulation usually requires agreement from all residents within the building. In most cases, individual flat insulation isn’t possible without collective consent.