Home Insulation Guide for UK Households

Why Home Insulation Matters

Insulation is one of the most effective ways to reduce heat loss, lower your energy bills and make your home more comfortable all year round. In a typical uninsulated UK home:

• Up to 25% of heat can escape through the roof
• Around 35% of heat can be lost through external walls
• Another 10% of heat may disappear through floors and draughts

By improving home insulation, you use less energy to heat your property, cut your carbon footprint and often improve your EPC rating — which can increase your home’s value and appeal to future buyers.

Quick Home Insulation Checklist

Use this simple checklist to see where you could be losing heat and money:

• Loft / Roof – Is there at least 270mm of loft insulation?
• Walls – Are your walls solid or cavity, and are they insulated?
• Floors – Are ground floors insulated or still bare boards/concrete?
• Windows & Doors – Do you have double glazing and good draught proofing?
• Pipes & Tank – Are pipes and hot water cylinder properly lagged?

If you’re unsure about any of these, an EnergyPlus home energy survey can help you understand your current insulation levels and the best upgrades for your property.

1. Loft & Roof Insulation

Loft insulation is usually the most cost-effective place to start. Heat naturally rises, so a poorly insulated loft lets warm air escape quickly, forcing your boiler or heat pump to work harder.

What is loft insulation?

Loft insulation is typically made from materials such as mineral wool, fibreglass or rigid boards laid between and over the joists. Current guidance in the UK recommends around 270mm of mineral wool insulation in the loft.

Benefits of loft insulation

• Can reduce heat loss through the roof by up to 25%
• Lower heating bills and improved energy efficiency
• Quick installation with minimal disruption
• Usually pays for itself through energy savings over a few years

Is your loft suitable?

Most homes with an accessible loft or attic space can benefit from insulation. Some factors we consider in our surveys include:

• Existing insulation depth and condition
• Ventilation and risk of condensation
• Whether you use the loft for storage or plan to convert it
• Any electrical or plumbing work running through the loft

For loft conversions or rooms in the roof, roof insulation between and over the rafters is often required instead of, or as well as, loft floor insulation.

2. Cavity Wall Insulation

Many UK homes built from the 1920s onwards have cavity walls: two layers of brick with a gap in between. If that gap is uninsulated, a lot of heat can pass through the walls.

How cavity wall insulation works

Cavity wall insulation involves drilling small holes in the external brickwork and blowing insulation material into the gap between the inner and outer walls. The holes are then filled to match the existing brickwork as closely as possible.

Benefits of cavity wall insulation

• Reduces heat loss through walls by up to 35%
• Helps maintain a more stable indoor temperature
• Can lower energy bills significantly, especially in larger homes
• Usually completed in a single day with minimal disruption

Is your home suitable for cavity wall insulation?

Not all properties are suitable. During a survey we check:

• Age and construction type of the walls
• Exposure to wind-driven rain
• Condition of existing brickwork and pointing
• Whether any insulation is already present

Our qualified assessors will only recommend cavity wall insulation where it is safe and appropriate for your property type and location.

3. Solid Wall Insulation

Older homes (typically built before 1920) often have solid walls with no cavity. These walls lose heat quickly but can still be insulated effectively from inside or outside.

Types of solid wall insulation

• Internal wall insulation (IWI) – Insulation boards or stud walls fitted to the inside of external walls.
• External wall insulation (EWI) – Insulation fixed to the outside of the property and covered with a protective render or cladding.

Benefits of solid wall insulation

• Significantly reduces heat loss through older walls
• Can transform cold, hard-to-heat rooms
• Helps reduce condensation and damp problems when installed correctly
• External systems can also refresh the appearance of tired brickwork

Solid wall insulation is usually more expensive than cavity wall insulation but can deliver substantial energy savings, particularly in larger or more exposed properties.

4. Floor Insulation

Cold floors are a common complaint in many UK homes. Insulating your ground floor helps reduce draughts, improve comfort and cut energy use.

Types of floor insulation

• Suspended timber floors – Insulation fitted between joists from beneath (via a cellar or crawl space) or by lifting floorboards.
• Solid concrete floors – Rigid insulation laid over the existing floor and finished with a new surface, usually during renovation.

Benefits of floor insulation

• Warmer floors underfoot, especially in living areas
• Reduced draughts through gaps in floorboards and skirting
• Lower heat losses and improved comfort at lower thermostat settings

During a survey we assess access, existing flooring, and potential disruption so you can decide whether floor insulation is a worthwhile upgrade for your home.

5. Draught Proofing & Secondary Measures

Even a well-insulated home can feel cold and inefficient if draughts are allowed to whistle through gaps around windows, doors and floorboards.

Common draught proofing measures

• Sealing gaps around doors and windows
• Fitting draught excluders to letterboxes and keyholes
• Blocking unused chimneys with purpose-made draught excluders
• Sealing gaps between floorboards and skirting boards

In addition, small improvements such as lagging pipes, insulating your hot water cylinder and fitting reflective radiator panels can all contribute to a more efficient home.

How Insulation Affects Your Energy Bills & EPC

Insulation reduces the amount of heat your home needs to stay comfortable. That means your boiler or heat pump runs for shorter periods and at lower settings. Over a typical UK heating season, this can add up to substantial savings.

Improved insulation usually leads to a better Energy Performance Certificate (EPC) rating. This rating is increasingly important for:

• Resale value and buyer interest
• Meeting future rental regulations (for landlords)
• Access to some grants and funding schemes

As part of our home energy service we can advise which insulation upgrades will have the biggest impact on your EPC score and long-term running costs.

Grants, Funding & Finance Options

Depending on your circumstances and where you live in the UK, you may be able to access help with the cost of insulation. This can include:

• Government-backed energy efficiency schemes
• Local authority or regional funding programmes
• Support from energy suppliers for eligible households

Our team keeps up-to-date with the latest schemes and can guide you through what’s currently available and whether you might qualify. Where funding isn’t available, we can still help you plan work in stages to suit your budget.

Our Home Insulation Process

EnergyPlus provides a straightforward, customer-focused service to help you insulate your home with confidence.

1. Initial consultation – We discuss your property, current issues and priorities.
2. Home energy survey – A qualified assessor inspects your home, identifies heat loss areas and checks suitability for different insulation types.
3. Clear recommendations – You receive a tailored plan outlining the most effective measures, estimated savings and expected payback.
4. Installation – Experienced installers complete the agreed work, following industry standards and best practice for your property type.
5. Aftercare – We provide documentation, guidance on ventilation and heating settings, and support if you have any questions after installation.

Every home is different. Our role is to help you make informed decisions based on accurate information and realistic savings.

Frequently Asked Questions About Home Insulation

Will insulation make my home too warm in summer?

Insulation slows the movement of heat in both directions. In winter it helps keep heat in, and in summer it can help keep excessive heat out, especially in lofts and roofs. Good insulation, combined with sensible ventilation and shading, usually leads to a more comfortable home all year round.

How long does insulation last?

Most modern insulation products are designed to last for decades. Loft, wall and floor insulation installed correctly should continue to perform for the lifetime of the building, although occasional checks are advisable to ensure it hasn’t been disturbed or damaged.

Will there be a lot of disruption?

It depends on the type of work. Loft and cavity wall insulation are often installed in a day with minimal disruption. Solid wall and some floor insulation can take longer and may require clearing rooms or lifting floors, but we plan work carefully to keep disturbance to a minimum.

Can insulation cause damp or condensation?

Insulation should always be installed alongside suitable ventilation and moisture management. When designed and fitted properly, insulation can actually help reduce condensation and cold spots. Our surveyors check for existing damp issues and advise on any remedial work needed before insulation is added.

Next Steps: Plan Your Home Insulation Upgrade

Whether you want to cut rising energy bills, make a cold room usable again, or prepare your home for low-carbon heating, improving insulation is the ideal starting point.

EnergyPlus works with homeowners across the United Kingdom to deliver practical, cost-effective insulation solutions tailored to each property. From modern apartments to older solid-wall houses, we can help you understand your options and choose the right upgrades.

Use the form below to arrange a free, no-obligation discussion with our team.