The definitions below apply to this document only and are not intended to be applied in other circumstances.
Building control body A local authority or an approved inspector.
Common spaces Spaces which are used mainly for circulation, e.g. a corridor or lift lobby.
Cross-ventilation The ability to ventilate using openings on opposite façades of a dwelling. Having openings on façades that are not opposite is not allowing cross-ventilation, e.g. in a corner flat.
Dynamic thermal modelling A method of building modelling that predicts the internal conditions and energy demands of a building at short time intervals using weather data and building characteristics.
Easily accessible Defined as one of the following.
A window or doorway, any part of which is within 2m vertically of an accessible levelsurface, such as the ground or basement level, or an access boundary.
A window within 2m vertically of a flat or sloping roof (with a pitch of less than 30 degrees) that is within 3.5m of ground level.
Effective area The area through which air flows after the resistance of airflow has been taken into account.
Equivalent area A measure of the aerodynamic performance of an opening. It is the area of a sharp-edged circular orifice through which air would pass at the same volume flow rate, under an identical applied pressure difference, as through the opening under consideration.
Floor area The area of the residential unit, measured to the internal face of the perimeter walls at each floor level.
NOTE: This area is the gross internal area as measured in accordance with the Code of Measuring Practice by the Royal Institution of Chartered Surveyors (RICS).
Floor area of the room The area of the room, measured to the internal face of the perimeter walls. Where a room serves more than one activity, e.g. open-plan kitchen and living room, the area with the largest glazing area should be assessed and the room area calculated based on a room depth no greater than 4.5m from the glazed façade.
Free area The geometric open area of a ventilation opening. This area assumes a clear sharp-edged orifice that would have a coefficient of discharge (Cd) of 0.62.
Glazing area The area of transparent material, not including the window frame.
Guarding A barrier that denies people access to another area, for example the floor below.
Louvre A set of angled slats that allow air or light to pass through.
Passive means Any means of cooling a building which is not mechanical cooling (e.g. air conditioning). Openable windows or mechanical ventilation fans are considered to be passive means of cooling.
Purge ventilation Ventilation of rooms or spaces at a relatively high rate to rapidly dilute pollutants and/or disperse water vapour.
Residential units Habitable rooms or a suite of habitable rooms. Examples of a residential unit include, but are not limited to, a flat or rooms that are similar to a flat in care homes or student halls of residence.
Shared communal rooms Rooms in buildings containing dwellings or residential units, which provide facilities for the residents, e.g. a shared living room, kitchen or laundry room.
