Compact Buildings

  • Physical Principle:
    Convection, Conduction, Radiation
  • Method for Thermal Comfort:
    Avoiding heat loss, heat gain

Compact buildings reduce energy losses by minimizing the surface area through which heat can escape.

Heat transfer between the interior and the outdoor environment occurs primarily through the building envelope (walls, roof, and floor). The larger the
exterior surface area, the more opportunities there are for heat to be lost in winter or gained in summer.

A compact form has a low surface-to-volume ratio. This means:

- less exterior surface area per unit of indoor space

- reduced heat loss in winter

- reduced heat gain in summer

Conversely, complex or highly articulated building forms significantly increase the surface area without adding much usable volume. This leads to higher
heat transfer and greater heating and cooling demand.

For example, a detached single-family house has more exposed exterior surface area than a row house. When two buildings share walls, the shared
surfaces no longer lose heat to the outside, which improves the surface-tovolume ratio and reduces heating and cooling demand.

The surface-to-volume ratio (A/V ratio) describes the relationship between the area of a building’s exterior surfaces (A) and the enclosed indoor volume (V).

It indicates how much building envelope exists in proportion to usable indoor space.

A high A/V ratio means a lot of exterior surface for a small volume → more heat loss in winter and more heat gain in summer.

A low A/V ratio means less exposed surface relative to the interior volume → better thermal performance and lower energy demand