Items where Subject is "Appendix D: Methods of measurement"
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- Appendix D: Methods of measurement (13)
Effective clear width (door stop to projecting ironmongery)
Effective clear width (door stop to door leaf)
NOTES:
1. As an alternative to using the values in the table, the floor space factor may be determined by reference to actual data taken from similar premises. Where appropriate, the data should reflect the average occupant density at a peak trading time of year.
2. Where accommodation is not directly covered by the descriptions given, a reasonable value based on a similar use may be selected.
3. Where any part of the building is to be used for more than one type of accommodation, the most onerous factor(s) should be applied. Where the building contains different types of accommodation, the occupancy of each different area should be calculated using the relevant space factor.
4. For detailed guidance on appropriate floor space factors for concourses in sports grounds refer to Concourses published by the Football Licensing Authority.
5. Alternatively the occupant number may be taken as the number of fixed seats provided, if the occupants will normally be seated.
6. Shops excluding those under item 10, but including: supermarkets and department stores (main sales areas), shops for personal services, such as hairdressing, and shops for the delivery or collection of goods for cleaning, repair or other treatment or for members of the public themselves carrying out such cleaning, repair or other treatment.
7. Shops (excluding those in covered shopping complexes but including department stores) trading predominantly in furniture, floor coverings, cycles, prams, large domestic appliances or other bulky goods, or trading on a wholesale self-selection basis (cash and carry).
In every case measure the volume contained by all of the following.
a. Under surface of roof.
b. Upper surface of lowest floor.
c. Inner surface of enclosing walls.
When there is not an outer enclosingwall, measure to the outermost edge of the floor slab.
The measured volume should include internal walls and partitions.
a. Cubic capacity of a building Internal wall or partition
b. Cubic capacity of compartments or separated part of a building
Diagram D2 Cubic capacity
a. Surface area: roofs and rooflights In each case measure the visible area
b. Floor area: Room, garage, conservatory or outbuilding, measure to inner surface of enclosing walls
c. Floor area: Storey, part or compartment, measure to inner surface of enclosing walls and include internal walls and partitions
Height of building
NOTES:
1.In assembly buildings (purpose group 5), a gallery is included as a storey, but not if it is a loading gallery, fly gallery, stage grid, lighting bridge, or any gallery provided for similar purposes, or for maintenance and repair.
2.In other purpose group buildings, galleries are not counted as a storey.
3.For the definition of basement, see Appendix A.
Height of top storey measured from upper floor surface of top floor to ground level on lowest side of building
Height of top storey excludes roof-top plant areas and any top storeys consisting exclusively of plant rooms
Free area measured at right angles to air flow
Free area for louvred vent = a1+a2+a3+a4+a5
The number of occupants of a room, storey, building or part of a building is either of the following.
a. The maximum number of people it is designed to hold.
b. In buildings other than dwellings, the number of people calculated by dividing the area of
a room or storey(s) (m2) by a floor space factor (m2 per person) such as given in Table D1 for
guidance.
Counters and display units should be included when measuring area. All of the following should
be excluded.
a. Stair enclosures.
b. Lifts.
c. Sanitary accommodation.
d. Any other fixed part of the building structure.
Travel distance is measured as the shortest route. Both of the following should be observed.
a. If there is fixed seating or other fixed obstructions, the shortest route is along the centre line of
the seatways and gangways.
b. If the route includes a stair, the shortest route is along the pitch line on the centre line of travel.
Width is measured according to the following.
a. For a door (or doorway), the clear width when the door is open (Diagram D1).
b. For an escape route, either of the following.
i. When the route is defined by walls: the width at 1500mm above finished floor level.
ii. Elsewhere: the minimum width of passage available between any fixed obstructions.
c. For a stair, the clear width between the walls or balustrades. On escape routes and stairs,
handrails and strings intruding into the width by a maximum of 100mm on each side may be
ignored. Rails used for guiding a stair-lift may be ignored, but it should be possible to park the
lift’s chair or carriage in a position that does not obstruct the stair or landing.
The free area of a smoke ventilator should be measured by either of the following.
a. The declared aerodynamic free area in accordance with BS EN 12101-2.
b. The total unobstructed cross-sectional area (geometric free area), measured in the plane where
the area is at a minimum and at right angles to the direction of air flow (Diagram D7).