From an urban design perspective high density accommodation is particularly attractive because agglomeration means that the overall energy use is far less than it otherwise would be. This is certainly the case when it comes to heating systems.

In traditional dwelling houses each home has its own dedicated boiler that satisfies all of the heating and hot water demand. This method is also seen in many flats due to the flexibility of the approach.

Larger heating systems are, however, inherently more efficient than smaller ones, especially when the heating demand becomes large enough to make combined heat and power (CHP) systems viable. It often, therefore, makes sense therefore to pursue a single heating system for multiple dwellings.