They want to make the flagship historic park in Stalybridge, Greater Manchester, more sustainable by reducing its carbon footprint.
The green makeover includes a ground-source heat pump for the new pavilion, which uses latent heat in the ground to cut out the need for expensive gas.
Infrared taps meanwhile will save water while motion-sensor lights will save electricity in the pavilion.
"The new maintenance depot meanwhile will include a harvesting tank to collect rain water for irrigating," said a spokesman.
"This will be particularly useful during times of drought and for washing tools and equipment, recycling and composting facilities."
A £4m grant from the Heritage Lottery Fund and £1m from Tameside Council will help round off the project this summer.
"We want to enhance the best features of the Victorian park but provide modern, highly efficient facilities."
Councillor Kevin Welsh said: "Sustainability has been a key feature of this project, which is about developing the park not just for now but for future generations.
Councillor Barrie Holland who chairs the authority’s carbon-reduction panel, said: "The ground-source heating pump will power underfloor heating.
"This is great news for the environment and our carbon footprint and it will also save money."