The project is an integrated infrastructure building for power supply and waste collection located in the old district of Inner Harbor, Macau, with the code M30. It was commissioned by two public amenity suppliers: one to provide a power station to supply electricity to the neighborhood and one to provide a garbage disposal unit with public access. The project, although small – with a total built area of 30 square meters, was complex to solve. The engineering and pragmatic requirements of two different clients needed to be satisfied on a tight site, in addition to the dilemma of how to insert a new industrial building into a historical residential district. The building needed to be considered at multiple scales. We therefore adopted several design tactics in order to resolve the contradictions of the brief and its integration into the urban fabric: namely regarding massing, working with section, reconciling circulation, and the use of materials. We expanded the brief and the goals of the project to go beyond satisfying the programmatic infrastructural requirements to capitalize on the site’s unique position at the intersection of courtyards and historic roads that define the contemporary city and the historic city. Our objective for the building was for it serve as a bridge between these conditions, enhancing the historic site with the potential to generate a vibrant heritage-based district to benefit Macau’s status as a heritage destination. The M30 infrastructure building adroitly navigates a challenging setting on a tight urban lot in the buffer zone of the Historic Centre of Macao World Heritage site. Using a stacked design, the new structure cleverly accommodates a waste collection station and a transformer room commissioned by two different municipal agencies. The dynamic architectural massing creates an interplay with the neighboring houses and public space. The material palette combines vernacular brickwork that echoes the adjacent older buildings with weathered steel and stainless-steel detailing that provides a textural contrast. With an impact beyond its modest size, the project exemplifies innovative new design in a heritage context.