Climate Action Network West Midlands met with Andy Street and WMCA's chief executive Laura Shoaf to plead for action over the energy and cost of living crises.
Ros Partridge, Friends of the Earth Stourbridge, said: "Despite the revised energy price cap, many more households will suffer from fuel poverty this winter" the campaigners write in an open letter. "Tens of thousands of people in our region are facing a financial crisis with attendant misery, ill health and more extreme consequences.
"We are deeply concerned by the lack of co-ordinated action at Regional and Local Government level to help households deal with this crisis."
Mr Street responded to the environmentalists: "The response to fuel poverty must be a combination of national, regional and local activities. Short-term action on fuel poverty is being led primarily by our local authorities, several of whom have launched extensive programmes and dedicated activities.
"However, the WMCA has a key role to play in the longer term, as well as some short-term responsibilities, as we address the underlying issues".
The campaigners want the authority to establish a not-for-profit municipal enterprise for retrofit along similar lines to Glasgow City Region's Housing Energy Retrofit Programme.
Ms Partridge added: "This measure would focus on the most vulnerable households, reinvest any surplus earned from those who can afford to pay for retrofit services and ensure the highest standards of work.
"A large scale retrofit programme would help alleviate fuel poverty, reduce demand for gas, cut carbon emissions and create skilled and semi-skilled jobs."
In Dudley Wood, pensioners Dennis and Jean Green had their property retrofitted under the Greener Homes Greener Lives scheme, a partnership between Dudley Council and Equans UK.
Jean said: "I did feel a difference - when I sat under the window, it's much warmer than it was before. The upgrade really looks lovely from the outside. Also inside - with having to take the windows out and everything, we've got an extra window ledge now. They really look nice."
Green Homes Greener Lives retrofitted 200 Dudley Council-owned properties with vulnerable residents and was shortlisted for a 2022 Inside Housing Development Award.
Last month, it was announced Dudley will host the pilot of the Combined Authority's Net Zero Neighbourhood project, designed to create low carbon communities. The Brockmoor area south-west of the town centre has been chosen for the £2 million demonstrator, which will deliver energy efficiency upgrades to 300 homes.