Consideration of the local environment is also vital. The orientation of the available land will have a big impact on the design of the house. If the house is to be built on a small block in the inner city, there may be limitations to how much north sun it will be exposed to. Small blocks that have a longer east-west axis with narrow north facing profile mean that traditional passive solar designs need to be modified to maximise northern exposure. In order to maximise the benefits of passive solar design and maintain comfortable temperatures, there are several elements of overall house design that must be considered.
Thermal mass is the amount of potential heat storage capacity available in a material.
In a building, materials with a high thermal mass value include a concrete slab with a tiled floor, brick, stone or earthen walls, or even water tanks. When positioned correctly inside the house, thermal mass can store heat during the day in winter, and re-radiate it at night time. During summer the thermal mass is protected from direct solar radiation and can act as a heat sink in hot weather to give cooler indoor temperatures. Insulation is vital to maintain even temperatures in a passive solar home. Insulation keeps warmth inside the house in cold weather, and prevents heat from entering when it is hot.