Retrofit Knowledge Bank

A jargon-busting whistle-stop tour of all the Retrofit essentials, with key information you might need to get started on your home energy efficiency refurb projects. Read on to explore many of the retrofit options available to you, their benefits, and things you might need to consider for each of them.

A modern Air Source Heat Pump outside a house

Air Source Heat Pump (ASHP)

An air source heat pump absorbs heat from the outside air (even when the weather is cold) to heat your home and water.

They use electricity to run, but the heat output can be around four times the electricity input.

Find Out More About Air Source Heat Pumps

Ground-source heat pump (GHSP) - represented by a cottage with upturned earth leading to the front door

Ground Source Heat Pump (GSHP)

A ground source heat pump absorbs heat from the ground (even when the ground feels cold) to heat your home and water.

It uses electricity to run, but the heat output can be around four times the electricity input.

Find Out More About Ground Source Heat Pumps

External Wall Insulation (EWI) - a close-up picture of thick exterior walls

External Wall Insulation (EWI)

External wall insulation (EWI) can be used on the outside of homes with solid walls.

It means you lose less heat through your walls.

Find Out More About External Wall Insulation

Internal Wall Insulation (IWI) - an interior wall with a plant by a window

Internal Wall Insulation (EWI)

Internal wall insulation (IWI) can be used in homes with solid walls.

It means you lose less heat through your walls.

Find Out More About Internal Wall Insulation

Cavity Wall Insulation - illustrated by a red brick wall

Cavity Wall Insulation (CWI)

Cavity wall insulation (CWI) can be used in homes with cavity walls (the external walls of the house have a gap between two leaves of brickwork).

It means you lose less heat through your walls.

Find Out More About Cavity Wall Insulation

Loft insulation - person with gloves and boiler suit installing

Loft Insulation

Insulation that can be rolled out in your loft (between and above ceiling joists) to reduce the amount of heat lost through the ceiling.

Find Out More About Loft Insulation

Underfloor insulation - a rug covering a wooden floor

Underfloor Insulation (UFI)

Insulation that can be fitted under suspended timber or solid floors to reduce the amount of heat lost through the floor.

Find Out More About Underfloor Insulation

A plant by a window

Windows & Doors

Replacing single glazing or old double glazing with new double or triple glazed windows and doors can reduce heat loss and draughts.

Find Out More About Replacing Windows and Doors

An extractor fan on a green tiled backround

Ventilation (required when insulating)

We generate a lot of moisture in the home through cooking, washing and breathing.

This moisture often escapes through gaps and cracks around the home (draughts).

Find Out More About Ventilation