The UK Green Building Council has warned Liz Truss that the energy price crisis cannot be fixed permanently without measures to improve energy efficiency of homes and other buildings.

The membership body, reacting to the new prime minister’s £150bn plan to freeze energy bills, said although the prime minister was right to announce immediate relief, measures must also be implemented to cut “wasteful energy use from our leaky homes and buildings”.

Simon McWhirter, director of communications, policy and places the membership body, said: “Subsidising gas is not sustainable long term when over a quarter of heat is wasted out of our badly insulated housing and building stock.

“We’re left with a huge policy gap. If global prices are still high when the immediate support ends, we’ll still be in exactly the same place paying for gas heating that leaks out of every uninsulated roof and wall.”

The call was echoed by Gavin Smart, chief executive of the Chartered Institute of Housing.