Retrofit glossary

Use this glossary to improve your understanding of commonly used terms in the climate change debate.

Archetype

In the context of retrofitting, 'archetypes' refer to groupings of buildings that share common characteristics, such as construction era, building materials, layout, or energy performance.

Air source heat pump

An air source heat pump (sometimes referred to as an air-to-water heat pump) transfers heat from the outside air to water. This in turn heats rooms in your home via radiators or underfloor heating. It can also heat water stored in a hot water cylinder for your hot taps, showers, and baths.

Building envelope

The building envelope serves as the physical barrier between a structure's interior and exterior environments. It includes walls, windows, doors, roofs, and floors, all working together to shield the building from external elements. The design of the building envelope is crucial for enhancing a building's energy efficiency, thermal comfort, and overall durability.

Carbon neutral

Carbon neutral refers to counterbalancing greenhouse gas emissions by investing in 'carbon offsetting' measures. This involves supporting carbon sinks, such as trees, and carbon capture technology that remove emissions from the atmosphere to create carbon neutrality.

Climate change

Climate change refers to changes in the world's weather, particularly the warming of the planet. This warming is believed to be caused by human activities that increase the levels of carbon dioxide and other greenhouse gases in the atmosphere.

Climate emergency

A climate emergency refers to serious and urgent problems caused or likely to be caused by changes in the world's weather. This includes the warming of the planet, primarily due to human activities that increase the levels of carbon dioxide and other greenhouse gases in the atmosphere.

Co-benefits

Co-benefits refer to additional advantages that arise from climate policy actions or measures. These can include: 

1. Secondary benefits from climate policy actions
2. Secondary climate benefits from other policy actions
3. A combination of climate and non-climate benefits, both of which are targeted under an integrated policy programme

Community energy

Community energy projects involve residents in the production and use of sustainable energy. Profits are reinvested into the community or shared among members. This direct involvement allows residents to make sustainable energy choices, enhancing energy security, independence, and affordability.

Decarbonise

Decarbonising is the the process of reducing or eliminating carbon dioxide emissions from a process (like manufacturing or energy production) or within an environment.

Decent Homes Standard

The minimum standards that social homes are required to meet, as introduced by the UK government.

Deep retrofit

A deep retrofit refers to a comprehensive renovation of a building's systems, using best practices to achieve at least a 50% reduction in both total energy use and greenhouse gas emissions.

Domestic emissions

In the UK, domestic emissions refer to greenhouse gases produced from residential activities like heating, cooling, cooking, and other household energy uses. These emissions significantly contribute to the country's overall carbon footprint and are crucial in national efforts to reduce greenhouse gas emissions.

Embodied carbon

Embodied carbon refers to the total carbon emissions associated with a building's lifecycle, including raw material extraction, material transport, manufacturing, and construction.

Energy efficiency

The amount of energy required to achieve a desired result, such as heating a home. By using less energy to accomplish the same task, we can improve energy efficiency.

Energy system retrofit

Installing or replacing an energy system with one that is more energy efficient than the existing system. For example, replacing a gas boiler with a heat pump.

Energy use intensity (EUI)

Energy use intensity is a measure of how much energy a building uses per area over a given time.

Energy Performance Certificate (EPC)

An EPC is a legally valid document that provides an energy efficiency rating (displayed on an A to G scale) for a property's running costs.

This rating considers the potential energy performance of the property itself (the fabric) and its services (heating, lighting, hot water, etc.).

Fabric first

Fabric First is a type of retrofit that focuses on improving your home's ability to retain heat. It involves upgrading anything that separates the outdoors from the indoors, such as floors, walls, and windows.

Fossil fuels

Fuels like gas, coal, and oil, formed underground from plant and animal remains millions of years ago.

Fuel poverty

Fuel poverty in England is defined using the Low-Income Low Energy Efficiency (LILEE) indicator. A household is considered fuel poor if it:

• Lives in a property with a fuel poverty energy efficiency rating of band D or below
• Has a residual income below the official poverty line after spending the required amount to heat their home

Green Homes Grant Local Authority Delivery

The Green Homes Grant Local Authority Delivery scheme aims to improve the energy efficiency of homes of low-income households, focusing on energy performance certificate (EPC) ratings of E, F, or G.

It aims to reduce fuel poverty, phase out high-carbon fossil fuel heating, and support the UK's commitment to net zero by 2050.

Green skills

The knowledge, abilities, values, and attitudes needed to live in, develop, and support a society that reduces the impact of human activity on the environment.

Greenhouse gas emissions

Greenhouse gasses are gaseous compounds (like carbon dioxide or methane) that absorb infrared radiation, trap heat in the atmosphere, and contribute to the greenhouse effect.

Heat networks

Heat networks distribute heat or cooling from a central source to various customers in a geographic area, eliminating the need for individual boilers or electric heaters in each building.

They use local sources of low-carbon heat, making them essential for the UK to achieve net zero. In high-density urban areas like Wandsworth, they are often the most cost-effective low-carbon heating option.

Mass flow rate

Mass flow rate is a measurement of the amount of mass passing a single point over a period of time. This calculation is used when calibrating an air source heat pump.

Net zero

When the total greenhouse gas emissions from human activity are equal to the amount removed from the atmosphere, aiming to reduce global warming. The UK is committed to reaching net zero by 2050, and we aim to achieve this by 2043.

Oversize factor

 The heat output from radiators divided by the heat loss of a room. This calculation is used when installing a heat pump to see what type and size of heat pump is needed for the room, and if the room would benefit from other efficiency measures to prevent heat loss.

Parity Projects

Parity Projects uses data science, software, and analysis to help its clients deliver energy efficiency efficiently, and effectively.

Parity Projects are an independent organisation that works with local authorities and landlords of every size to develop cost-effective retrofit programmes that meet their cost, comfort, and carbon goals.

Planning application

A planning application is a document required to ask official permission from a local government authority to construct a new building or make changes to an existing one.

Retrofit

Retrofit refers to any improvement work on an existing building to improve its energy efficiency, making it easier to heat, able to retain that heat for longer, and replacing fossil fuels with renewable energy.

Retrofit measures

Retrofit measures refer to specific upgrades aimed at improving a building's energy efficiency.

Examples include installing a heat pump and replacing single glazing windows with double glazing.

Standard Assessment Procedure (SAP)

The Standard Assessment Procedure (SAP) is the methodology use by the government to estimate the energy performance of homes.

Sustainable construction

Sustainable construction involves activities that minimise negative impacts and maximise positive impacts to achieve a balance in environmental, economic, and social performance.

Sustainable development

Sustainable development is a development that meets the needs of the present without compromising the ability of future generations to meet their own needs. It aims to balance the needs of economic growth, the environment, and social wellbeing.

London Plan

The London Plan 2021 is the Spatial Development Strategy for Greater London. It sets out a framework for how London will develop over the next 20 to 25 years, and outlines the Mayor’s vision for Good Growth.

National retrofit targets

The 2008 Climate Act committed the UK to reducing its greenhouse gas emissions by 80% by 2050 compared to 1990 levels.

It also established the Committee on Climate Change and set UK carbon budgets. Under the Net Zero Strategy, the UK aims to reduce emissions from public sector buildings by 50% by 2032 and 75% by 2037 against 2017 levels.

The Warm Homes Plan

The Labour government plans to upgrade millions of homes thorough their Warm Homes Plan. This initiative aims to provide families with cheaper energy bills and warm, future-proofed homes.

Wandsworth Adaptation and Resilience Strategy

The Adaptation and Resilience Strategy will support our pledge of delivering a fairer, more compassionate, and more sustainable borough. It will help the borough adapt to and increase its resilience against the impacts of climate change.

By implementing a robust and consistent approach to climate adaptation and resilience across all teams, we aim to reduce the impacts of climate change and ensure we can continue delivering our services effectively.

Wandsworth Air Quality Action Plan

This Air Quality Action Plan has been produced as part of our duties under London’s Local Air Quality Management regime. It outlines the action we will take to improve air quality in Wandsworth between 2023 and 2028.

Wandsworth Housing and Homeless Strategy

The strategy sets out our plan for housing and homelessness for 2023 to 2028.This includes new legislation and developments in the sector, meeting the climate aims set by the WESS, responding to building safety issues, and housing conditions.