As the weather cools down, many homeowners in the UK start to notice a rise in their energy bills, often attributed to heat loss in their homes. Addressing these heat loss spots keeps your home warm, saves money, and reduces your environmental impact. The energy price cap is due to rise again, with many factors quoted as the reasoning. Whatever the reason, the ordinary people will once again suffer the most. There are ways to reduce heat loss with little investment, and we’ll also discuss these tactics.
Heat loss spots – thermal bridges
Thermal bridges are areas in a building where heat transfers at a higher rate than the surrounding materials. These spots act like “highways” for heat, allowing it to escape more easily than in other, better-insulated home parts.
In simple terms, a thermal bridge is a path that allows heat to flow through a structure more rapidly than through the insulated areas. They occur when there’s a break in the insulation or when materials with different thermal conductivity come into contact, allowing heat to escape more easily. Thermal bridges significantly contribute to a building’s overall heat loss, making maintaining a comfortable indoor temperature harder and more expensive. Besides increasing energy bills, they can also lead to cold spots on walls or ceilings, which can cause condensation, dampness, and mould growth—potentially damaging your home’s structure over time.
Types of thermal bridges
Thermal bridges can be classified into three main categories based on how they occur:
1. Geometrical Thermal Bridges
Geometrical thermal bridges arise due to the shape and design of a building. Areas like corners, junctions between walls and floors, and intersections between walls and roofs are common spots for geometrical thermal bridges. These areas have more surface area exposed to external conditions, making them prone to higher heat loss.
- Example: Wall corners are often colder because they have a larger external surface area than internal surfaces, leading to more heat dissipation.
2. Construction Material Thermal Bridges
These occur when materials with high thermal conductivity are used in the building structure. Steel and concrete are excellent heat conductors, allowing heat to bypass insulation.
- Example: A steel beam passing through an insulated wall will act as a thermal bridge, conducting heat outwards much faster than the surrounding insulation.
3. Point Thermal Bridges
Point thermal bridges are caused by localised penetrations of the insulation system, such as bolts, fasteners, or anchor points in walls, windows, and roofs.
- Example: A metal bracket attached to an external fixture can create a point thermal bridge, providing a direct route for heat to escape.
How do thermal bridges work?
Thermal bridges work based on the principle of thermal conductivity. Materials with higher thermal conductivity (like metal or concrete) allow heat to move through them more rapidly, whereas materials with low conductivity (like insulation) slow heat transfer. When thermal bridges exist, they essentially bypass the insulation around them. This increases heat loss in those areas, lowering the home’s energy efficiency. This leads to higher energy bills and can create cold spots on walls and floors, where moisture condenses, potentially leading to structural damage over time.
Heat loss spots in your home
1. Windows and Doors
Windows and doors are notorious for letting warm air escape and allowing cold air to seep in. Even if closed, small gaps and poor insulation around the edges can result in significant heat loss.
How to Fix:
- Double or Triple Glazing: Upgrade your windows to double or triple glazing for improved insulation.
- Weather Stripping: Install weather stripping around doors and windows to seal gaps.
- Draught Excluders: Use draught excluders at the bottom of external doors to block cold air.
- Heavy Curtains: Thick curtains can also help by creating an extra layer of insulation during the winter months.
2. Walls
Homes built before the 1990s may have little insulation, allowing heat to escape through solid or cavity walls. Around 35% of heat loss can occur through uninsulated walls.
How to Fix:
- External Wall Insulation (EWI): External wall insulation is an excellent long-term solution. At EWI Store, we offer a range of render systems that can insulate your home’s exterior while improving its aesthetic appeal.
- Internal Wall Insulation: Adding internal insulation panels can be a viable alternative if external insulation isn’t possible.
- Cavity Wall Insulation: If your home has cavity walls, consider installing insulation to prevent heat from escaping.
3. Roofs and Attics
Heat rises; without proper insulation, much heat can escape through a roof or attic, accounting for as much as 25% of a home’s heat loss.
How to Fix:
- Loft Insulation: Adding loft insulation is one of the most cost-effective solutions to prevent heat loss. A layer of at least 270mm of insulation can make a noticeable difference.
- Insulated Roofing: Consider upgrading to insulated roofing materials for better thermal efficiency.
4. Floors
Uninsulated floors, especially in older homes, can cause significant heat loss, particularly in rooms above unheated spaces like garages or basements.
How to Fix:
- Underfloor Insulation: Installing underfloor insulation beneath wooden floors can trap warmth inside your home. If you have a suspended floor, insulating between the joists can help.
- Rugs and Carpets: Adding thick rugs or carpets can help retain warmth in rooms with cold floors.
5. Chimneys
An unused chimney can act as a conduit for heat to escape your home. Warm air can still rise and escape through the chimney flue, even with a closed fireplace.
How to Fix:
- Chimney Balloon: When the chimney isn’t used, use a chimney balloon or draught excluder to block the flue.
- Chimney Cowl: Installing a chimney cowl can prevent cold draughts while allowing ventilation.
6. Draughty Gaps and Cracks
Small gaps and cracks around your home, whether in the walls, floors or around pipework, may seem insignificant but can cumulatively result in substantial heat loss.
How to Fix:
- Sealant or Caulk: Use a silicone-based sealant to fill in any cracks or gaps around windows, doors, and pipe entries.
- Foam Strips: Foam strips can be used around doors and windows for an added layer of protection.
7. Radiators
Poorly placed or inefficient radiators can also contribute to heat loss, especially if they are not optimally heating the room.
How to Fix:
- Radiator Reflectors: Placing radiator reflectors behind your radiators can help to bounce heat back into the room rather than allowing it to escape through walls.
- Bleed Your Radiators: Make sure your radiators work efficiently by regularly bleeding them to remove trapped air.
- Radiator Covers: Avoid using thick radiator covers as they can trap heat. Instead, allow as much airflow as possible.
How to assess your heat loss spots – insulation survey
An insulation survey is a thorough assessment that helps pinpoint heat loss spots (thermal bridges) and evaluates the overall effectiveness of your home’s insulation. One of the most accurate ways to assess heat loss in your home is through a thermographic survey, often performed by professionals using infrared cameras. This type of survey allows you to see the exact locations where heat is escaping.
How it works:
- Infrared Scanning: A thermographic camera scans your home’s exterior and interior. The camera detects infrared radiation (heat) and translates it into a visual display, where warmer areas appear red or orange and cooler areas appear blue or green.
- Heat Loss Detection: The resulting thermal images will clearly show where your home is losing heat—from windows, walls, the roof, or other thermal bridges.
A blower door test is another effective way to assess your home’s energy efficiency. It’s particularly useful for detecting air leaks around windows, doors, and other openings.
How it works:
- Creating a Pressure Difference: A powerful fan is mounted on an external door, drawing air out of your home to create lower pressure inside than outside. This forces air to flow through gaps or leaks in the building envelope.
- Leak Detection: Once the fan is running, a technician will use tools like smoke pencils or thermal cameras to detect where air leaks into the home, revealing potential insulation gaps.
