V

Vapour barrier
A layer which is impermeable to moisture and air and applied to an element of construction to resist the passage of water vapour to cold parts of the structure where it would cause condensation.

Ventilation
The process of supplying fresh air to a space.

Visual comfort
Visual comfort is the result of the interaction between physical parameters and psycho-physiological sensations. Physical parameters that may be quantified are, for example, illumination, brightness, contrast, glare, etc. Psycho-physiological sensations are related to the quantity, distribution and quality of light. They are also influenced by visual contact with the outside environment. Therefore natural lighting gains need to be optimized, while respecting thermal requirements and summer comfort. In general, architects attempt to minimize the number of windows and doors on the north side, arrange bedrooms so that the windows face east, provide windows in opposite walls in the living room, and to design apartments across the full width of a building. The ratio between natural lighting and artificial lighting must be balanced. A systematic search must be made to increase natural light input in "service" rooms (kitchen, bathroom, etc.). Secondary lighting can be created by glazed transoms, or vertical or overhead lighting.

Volumetric heat capacity (Wh/(m³ K) or J/(m³ K))
The amount of heat stored in a unit volume of a material for each degree rise in its temperature.