David and Sorrel Williams are in the process of making their home cosier by insulating their home, including around this triple-glazed window with wood fibre.
They are among a group of volunteer homeowners who will be opening - and then closing their doors to keep the heat in - as part of Green Doors Day from 10am to 5pm on Saturday October 30.
They will be able to give hints and tips to people who are thinking of doing the same to save money and be kinder to the environment.
Tony Baker of Zero Carbon Shropshire, the group organising the event, said: "We hope lots of people get through our Green Doors.
"They're sure to get loads out of the day.
"From simple steps, such as draught-proofing, to more complex installations such as heat pumps and internal wall insulation, our Green Doors display a large range of modifications that we can all benefit from."
This year they will be showing two new homes, built to Passiv standards, currently the top of the class in terms of energy efficiency."
For more information and for the locations of the Green Doors please visit http://www.shrewsburygreendoors.co.uk/.