FATHER-and-son builders have had to be on their best behaviour on a house extension due to a film crew from Channel 4 watching them work.

Alan and Jamie Shaw, of A Shaw and Son, will feature in Sarah Beeny's show Double Your House for Half the Money. It will show them complete an extension designed specially for a family with four wheelchair users, who are moving from London to Sheffield.

Alan, 69, of Tennyson Close, Penistone, and son Jamie, 31, of Church Hill, Royston, have worked together since Jamie left school.Jamie said they quickly got used to the filming and made sure they were on their 'best behaviour'.

He said: "We always try and be polite and professional. You certainly have to mind your Ps and Qs while there are cameras on you."

The programme will air in the summer.