The UK’s housing stock is not in a good state when it comes to thermal efficiency. Almost four in ten UK homes were built before 1939. Many of them suffer heat loss like sieves and are difficult to insulate. These houses were built for heating by open coal fires and had large drafty windows to allow the fire to draw. They have very small rooms and solid walls with a single leaf of bricks. This structure makes wall insulation expensive and impractical. According to a study of 80,000 homes, a UK home with an indoor temperature of 20°C and an outside temperature of 0°C loses on average 3°C after five hours – three times faster than German homes.
What is a thermal bridge?
A thermal bridge refers to a house with poor insulation and therefore a poor energy performance because it emits large quantities of greenhouse gases. Indeed, living in an energy sieve means being faced with heat losses and having to increase the heating, which leads to high energy consumption. Moreover, the thermal comfort of the inhabitants of such houses is largely degraded, both in summer and winter. In winter, the heat does not remain in the building, while in summer the coolness has difficulty penetrating. Many modest households are subjected to this.
How to know if my home is a thermal bridge?
Recent research undertaken has shown that thermal bridging can be responsible for up to 30% of a building’s heat loss.
Buildings qualified as thermal bridges present a bad diagnosis of energy performance. New-built homes tend to have high EPC ratings, while older homes often have lower ratings of around D or E. The average EPC rating for a home in the UK is D.
Homes with a class F have an annual consumption between 330 and 420 kWh/m.
Homes with a G rating have an annual consumption that exceeds 420 kWh/m.420 kWh/m.
Future Homes Standard
From 2025, the Future Homes Standard will require CO2 emissions produced by new homes to be 75-80% lower than those built to current standards.
To achieve this, the government introduced major Building Regulations changes in June 2022, with new homes in England now needing to produce 30% less carbon emissions compared to the old regulation.
Ahead of the Standard coming into effect, a technical specification will be consulted in 2023 by the Department for Levelling Up, Housing and Communities (DLUHC), with the necessary legislation introduced in 2024, ahead of implementation in 2025.
The Department(DLUHC) believes that the new regulations will help the UK meet its net zero targets, and marks a stepping stone towards the introduction of the Future Homes Standard in 2025.
Why is the government trying to put an end to thermal bridging ?
Two main issues are involved :
- The first is economic: The inhabitants (tenants or owners) of a house reduce their energy expenses (thus their bills) if the house is well insulated and does not allow heat losses.
- The second is ecological: a thermal bridge emits a significant amount of greenhouse gases, which goes against the objectives of the government in the fight against the climate emergency. Thermal bridges thus contribute to the global warming.
Thermal bridge in co-ownerships: EPC or energy audit ?
There are two different ways to fight against thermal bridges in a co-ownership:
- Co-ownership of less than 50 plots: the EPC is mandatory if there is a collective heating system.
- Co-ownership of 50 plots and more: if the building permit was issued before June 1, 2001, it is not an EPC but an energy audit that is mandatory.
As far as heating is concerned, syndicates are required to individualize the heating costs if possible.
How to improve the energy performance of a house described as a thermal bridge?
Knowing the energy performance of my home
The energy audit is mandatory
It is mandatory for owners to perform an energy audit when selling a property that is a thermal bridge. This compulsory energy audit completes the EPC earlier carried out. It allows the buyer of the property to know the type of renovation and insulation work that needs to be done to improve the energy performance.
The energy performance certificate, commonly known as the EPC, is a mandatory document provided by the owner of a property to the future tenant or buyer. It lists the energy consumption of the property, particularly through the classes of the energy and climate labels. The lowest classes are F and G for both labels. There is a fixed penalty of £200, which is enforced by Trading Standards.
The most important measure to take in improving the energy performance of your home is to renovate it. This plays a crucial role in curbing thermal bridges.
What work should I do if my house is a thermal bridge ?
The loft is a part of the house that needs to be insulated as a priority because it requires low-cost insulation work and is quite profitable. The insulation of the loft is very important in the case of thermal bridges because hot air tends to escape upwards. Loft insulation will make a difference on your energy bills.
Roof insulation from the outside
It can be done either inside (loft) or outside. When it is done on the outside, the roof insulation does not encroach on the space inside your house. The disadvantage is rather in the price which remains higher than insulating the interior.
In addition to relieving your heating bills, window insulation also has a soundproofing advantage. Double or triple glazing is a very effective solution for reinforced insulation.
You can choose to insulate either the interior or exterior of your home. Exterior insulation has better results in terms of energy performance, but it is more expensive than an interior insulation. Whatever your choice, insulating your walls makes your home thermal efficient.
What financial aid is available for homeowners suffering from thermal bridges?
There are several financial aids available by the government to help renovate your thermal bridge.
The UK Energy Support (UKES) is an approved installer and supplier of free insulation and heating systems as part of ECO4 Scheme (final phase of the Energy Company Obligation), a scheme initiated by the UK government.
Homeowners can get a 100% FREE replacement of inefficient heating with the best electric heating systems and receive home insulation grants (free loft and cavity wall insulation grants), if they meet certain criteria. The programme started in 2013 but will come to an end in March 2026.
People in Scotland can install insulation through the government’s Warmer Homes Scotland scheme – if they meet certain requirements.
Just like the ECO scheme, Warmer Homes Scotland offers financial support to low-income and vulnerable households that are struggling to keep up with energy bills.
Loft insulation is a popular choice in this scheme. In 2017/2018 and 2018/2019, 10% of installations through the Warmer Homes Scotland grant were loft insulations.
People in Wales can install loft insulation in their homes through the government’s Nest scheme if they meet certain criteria.
Nest supports low-income and vulnerable people in Wales by offering free and impartial advice about home energy, as well as fundings for various home improvement.
If eligible, Nest will recommend a range of appliances that you can install for free, which will make your home warmer and reduce energy bills.
The Green Homes Grant was created to fund eco-friendly installations in more than 600,000 homes, as well as help tradespeople during an economic downturn.
The £2 billion initiative covered two-thirds of the cost of home improvements designed to cut energy bills and carbon emissions. Unlike the ECO, Warmer Homes Scotland, and Nest schemes, the Green Homes Grant initiative wasn’t limited to low-income households.
However, four months after being extended to March 2022, the program was cancelled.
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