A home buyer’s guide to insulation

What is insulation?

Insulation is a material installed throughout your property that can prevent heat from escaping during winter and entering during summer. Insulating homes works by trapping air in tiny pockets, slowing the transfer of heat between the inside and outside of your house.

Why is insulation important?

Good insulation in a home is essential for maintaining comfortable temperatures all-year-round. It can also help improve your home’s energy efficiency by reducing your energy consumption. Without good insulation, your heating system must work harder to maintain comfortable indoor temperatures, which may waste energy and money.

The benefits of good insulation

Insulating homes can be important for the following reasons:

• Reduces your energy bills by preventing heat loss and reducing the amount of heating required

• Prevents moisture problems by controlling condensation, which can reduce the risk of damp and mould growth in your home

• Decreases your carbon footprint, which can make your home more sustainable

• Improves comfort by preventing cold spots and draughts

• Reduces noise pollution, as insulation can act as a noise-cancelling barrier

• Makes homes more attractive to buyers who value energy efficiency and modern features

How insulation can reduce your energy bills and carbon emissions

Insulation in a home may help to reduce energy consumption by preventing heat from escaping through walls, roofs and floors. When heat can't escape easily, your heating system may run less frequently and for shorter periods. By using less energy for heating, you can effectively reduce your household's carbon emissions.

Where does your home need insulation?

Your home needs to be insulated from the roof down to the foundations. This includes the loft, walls, floors, windows, doors, pipes and radiators. Prioritise areas with the greatest heat loss first, such as the loft and walls. Even small gaps or poorly insulated sections can reduce the overall effectiveness. Make sure to assess properties thoroughly when viewing and identify any areas requiring insulation improvement.

Types of home insulation explained

Different insulation materials may suit different applications throughout your property.

• Matting is often the most popular way of insulating a loft, and it’s also used for floors and stud walls. It’s sold in rolls of varying depths and is usually made from fibreglass, rock fibre or sheep’s wool

• Loose-fill insulation is sold in bags and then poured out. Made from cellulose fibre, mineral wool, cork granules or vermiculite, it’s ideal for corners and less accessible areas of your loft

• Rigid insulation boards are typically used for ceilings, walls and floors and are made from polystyrene, polyisocyanurate (PIR), or polyurethane (PUR). The pieces must be cut to size before fitting

• Blown insulation is made from fire-resistant cellulose fibre. It’s used to insulate stud walls or lofts and must be installed by a professional

Wall insulation

Walls account for approximately 33% of heat loss in uninsulated homes, making them a priority when insulating homes.

The type of wall construction may determine which insulation method best suits your property:

• Cavity wall insulation sits within the gap inside cavity walls, filling it with insulating material (typically foam, beads or mineral wool), blown in through small holes drilled in the exterior wall

• Solid wall insulation can be applied internally or externally. External solid wall insulation involves fixing insulation boards to exterior walls and covering them with render or cladding. Internal applications require fixing insulation boards to interior walls with plasterboard over them

Roof and loft insulation

An uninsulated home may lose up to 25% of its heat through the roof. By insulating your roof effectively, you may experience less heat loss and reduced heating bills. If you have a flat roof, it may be best to insulate from above with a layer of rigid insulation board.

When moving into a new home that doesn’t have roof and loft insulation, you may want to prioritise this to avoid higher energy bills.

Floor insulation

Older homes with suspended timber floors may lose heat through floorboards. It’s important to fill any gaps with insulating foam to prevent heat loss. Floor insulation is especially important in properties where living spaces are above unheated areas, such as garages.

Window and door insulation

Insulating homes doesn’t stop at walls and floors. Windows and doors can account for heat loss in homes, too. Modern double- or triple-glazed windows offer better protection against heat loss and can help you save on heating bills, so always check the quality of the windows when viewing properties. Look for condensation between panes, which may indicate seal failure and reduced effectiveness.

Good door insulation can include both the door itself and draught-proofing around the frame. For external doors, you may want to use threshold strips and compression seals, whilst letterboxes can benefit from draught excluders.

Pipe and hot water cylinder insulation

Houses with insulation around hot water pipes and cylinders can help to prevent heat loss when hot water travels from your boiler. Uninsulated pipes may waste energy by heating the surrounding air rather than delivering hot water efficiently. Pipe insulation can consist of foam tubes that slip over pipes; these are available at most DIY stores and are easy to install.

Other ways to insulate your home

There are also other ways to insulate your home:

• Add thermal curtains for additional insulation over windows

• Install double-glazed windows if you currently have single-glazed panes

• Plug your fireplace when it’s not being used to prevent heat from escaping up the chimney, using chimney balloons or covers

Insulation in new build homes

New build properties must comply with the most recent building regulations, including energy efficiency. A brand-new home could be up to 65% more energy efficient than an older home, meaning you could save up to £979 per year on your running costs.3 You may even be eligible for a green mortgage with better interest rates.

How do new build insulation standards compare to older homes?

Modern building regulations require higher insulation standards than those applied to older properties. Most new builds feature cavity walls filled with insulation, insulated floors and lofts with a depth of around 270mm. David Wilson homes have highly thermally efficient insulation and argon-filled double-glazing as standard, allowing heat from the sun in whilst minimising heat loss.

Building regulations and energy efficiency requirements

Current building regulations set strict standards for insulation in a home, requiring specific thermal performance values, also known as U-values. Lower U-values can indicate better insulation performance – check this when buying a new home. These regulations ensure new builds deliver excellent energy efficiency, potentially reducing your carbon emissions and running costs.

How insulation improves EPC ratings

Energy Performance Certificates (EPCs) rate properties from most to least efficient, with A being the most efficient and G the least. Insulation in a home can play a crucial role in determining a home's rating. Good insulation in house structures often pushes ratings into B or C bands, whilst poor insulation results in D, E or F ratings.

New build homes typically achieve A or B ratings due to improved insulation and modern heating systems. Better EPC ratings can also improve marketability.

How to tell if a home is well-insulated

If you’re looking to understand the level of insulation in a home, there are a few things to check.

Signs of poor insulation

When viewing properties, check for signs of poor insulation, such as:

• Cold walls, floors or ceilings when touched during winter may indicate inadequate insulation

• Draughts around windows, doors and electrical sockets can suggest gaps in insulation or poor sealing

• Condensation forming on windows, particularly in bedrooms and bathrooms, often results from poor insulation, causing cold internal surfaces where moisture condenses

• Unusually high energy bills reported by the current owners could indicate the insulation isn't performing adequately

Check EPC reports and insulation information

EPC reports provide detailed information about insulation in a home. The report specifies whether walls have cavity or solid wall insulation, the depth of loft insulation, the type of window glazing, and the level of floor insulation. Each element receives a rating, helping you understand which areas need attention.

What to consider before you invest in insulation

Insulating homes can be expensive, so you may want to understand how well-insulated your property is before investing. You can weigh up the costs against your future energy savings, then decide whether to hire a professional to insulate your home.

Browse our collection of insulated new-build homes across the UK. Call our Sales Advisers at your nearest development to learn about our range of offers and find the right home for you.