Requiring higher than national minimum energy efficiency standards for new homes will cut carbon and also minimise energy costs for the inhabitants. (NB the Government’s proposed Future Homes Standard may prohibit this.) However, new homes have a lot of embodied energy; retrofitting existing homes and making better use of empty properties is the most efficient option. See the Exemplar Standard for all new homes in Glasgow.
(Ashden Action 6 31 Climate Actions for Councils)