Nelson Lancashire UK is dying. Its heritage, championed by Prince Charles and English Heritage has constrained development to such an extent that nothing can be changed. It is losing population at an alarming rate, and those remaining are ageing and racially entrenched. This paper describes an ambitious attempt to create a 21st century carbon-neutral future within a very regulated aesthetic. Nelson, as a Victorian boom-town, has no public space, and the housing is mainly terraces without gardens. The brief was to make difference without changing the historic character of the area. The competition-winning scheme for the Whitefield ward by CityLab and Maccreanor-Lavington Architects, Rotterdam starts with the insertion of a much-needed public space; this has several functions: It links the town with the canal; provides a pedestrian link to school and creates an edge to the town centre. However, beneath it, lie large water tanks that act as an inter-seasonal store, which combined with a bio-fuelled Combined Heat and Power plant provide heat and power for the neighbourhood in a sustainable way. The new insertion can be seen as a prosthetic for carbon-neutrality. To regenerate the city as a sustainable entity, it is necessary to reduce dramatically its carbon footprint. The heritage-led constraints limit opportunities to reconfigure anything, so the design-team focussed on the co-generation of heat and power, using bio-diesel produced from waste cooking oil. The main issue with co-generation, is how to equalise the demands between the need for more heat in winter and the constant demand for electricity. The solution, is to use waste heat in summer to heat a large thermal store, which can then be used in winter – thus regulating the demand between seasons, and optimising the efficiency of the plant. With the CHP plant adjacent and the inter-seasonal store beneath and its urban design functions, the public space can be seen as a total sustainable solution to a complex political, social and ecological condition.