From the Government Website:

https://greenhomesgrant.campaign.gov.uk/

Wrap up your home this winter

Make your home warmer and your energy bills cheaper with a Green Homes Grant. 

Homeowners in England, including landlords, can get up to £5,000 to pay part of the cost of energy saving measures like insulation. Low income households can get 100% of the costs of work covered up to £10,000.

Make sure you’re one of the 600,000 households who could save up to £600 a year on energy bills by applying today. Installing energy efficient home improvements also cuts emissions, which is better for the environment.