Energy in new buildings

Energy in buildings

We’re helping London’s homes, businesses and public buildings to use less energy and save money on their energy bills.

Improving our existing building stock

We have an ambitious target to cut carbon emissions in London by 60 per cent by 2025. As homes and workplaces account for around 78 per cent of CO2 emissions in London, and with 80 per cent of the existing building stock likely to still be in place in 2050, it is important to improve the energy performance of these buildings in order to cut costs and carbon.

Our retrofit programmes RE:NEW and RE:FIT involve using new technology on old buildings to make them more energy efficient:

RE:NEW - we’re making London’s homes warmer and more energy efficient through RE:NEW, the award winning domestic retrofit programme. RE:NEW helps organisations such as London boroughs, housing associations, and universities to implement retrofit projects helping to cut carbon emissions and alleviate fuel poverty. Find out more about the RE:NEW programme

RE:FIT - we’re helping London’s public buildings to cut their energy consumption through RE:FIT, the award winning non-domestic retrofit programme which offers support to London boroughs, schools, universities, hospitals, leisure centres and museums to implement retrofit projects and achieve large financial savings. Find out more about the RE:FIT programme

Energy Leap - in his vision, A City for all Londoners, the Mayor committed to developing new and innovative approaches to energy efficiency, starting with an early trial of net-zero energy retrofitting of homes.On 15 February 2017, the Mayor allocated £450,000 capital funding for the Energy Leap Project which will match fund at least ten zero energy retrofit projects. Find out more about the Energy Leap Project pilots 2017-18.

Improving the energy performance of new buildings

We are making sure new buildings are designed and built in a way that cuts energy use and carbon emissions through our energy planning policies. The aim is make sure that Londoners have excellent, energy efficient and comfortable homes - both now and in the years ahead.

Developers must follow the energy hierarchy when planning a new building. This means:

being lean: using less energy, by improving the energy efficiency of the building itself, so less energy is needed for heat

being clean: supplying energy efficiently, for example by using district heat networks

being green: using renewable energy technologies, like solar photovoltaic panels or heat pumps

We work with local planning authorities and developers to make sure that new projects follow this hierarchy. They must also meet the targets in Policy 5.2 of the London Plan to reduce carbon dioxide (CO2) emissions in new buildings.

Major development proposals must have an energy strategy which shows how they are applying the hierarchy above. It must also detail how the development will meet targets to cut CO2 emissions. We’ve produced a guide to help developers and energy consultants produce an energy strategy.

Each year we report what developers are doing to cut CO2 emissions from proposed buildings. This energy monitoring report also has information on the technologies that are going to be installed.

Overheating and cooling

Overheating in homes (and associated increased demand for cooling such as air conditioning) is the phenomenon of a person experiencing excessive or prolonged high temperatures within their home, resulting from internal and/or external heat gains, and which leads to adverse effects on their comfort, health or productivity.  Overheating disproportionality affects vulnerable members of the community such as elderly.

Overheating in homes is being increasingly recognised by the building industry as a significant and growing problem given:

  • Increasing average temperatures and hotter summers due to climate change.

  • A growing and ageing population.

  • Urbanisation and increasing housing densities.

  • Construction practices – improving energy efficiency to meet higher standards and air tightness for winter; and increasing glazing proportions.

We’re helping developers of new homes in London to ensure potential for overheating is considered early in the planning and design process. We have commissioned research Creating benchmarks for cooling demand in new residential developments  to develop a set of good practice cooling energy demand benchmarks for typical apartment dwelling types, based on reasonable design measures.

The research establishes good practice benchmarks based on dwelling designs which include reasonable design measures to reduce the need of active cooling and the risk of overheating in compliance with the cooling hierarchy identified in London Plan Policy 5.9. In summary it finds:

  • Climate change will have a big influence on the ability of a passive design strategies for new development to be effective in the long-term.

  • There is no ‘one size fits all’- design approaches should be bespoke to type of building, occupants, expected lifetime and location.

  • The ability to naturally ventilate a dwelling has a major impact on its cooling demand, however, this benefit will reduce as external conditions get warmer.

  • Building designers should maximise opportunities for cross ventilation.

The research includes a simple checklist which can be used to help determine level of overheating risk and compliments existing guidance that we issue to developers when preparing energy assessments for new development.