What does enclosed or substantially enclosed mean?
Substantially Enclosed - Premises are substantially enclosed if they have a ceiling or roof, but there are permanent openings in the walls which are less than half of the total areas of walls, including other structures which serve the purpose of walls and constitute the perimeter of premises. This is known as the 50% rule.
When determining the area of an opening, no account can be taken of openings in which there aredoors, windows or other fittings that can be open or shut. A roof includes any fixed or movable structures, such as canvas awnings (Smokefree England)
This smoking shelter (left) was erected prior to the smoking ban and the owner wished to know whether it complied. The perimeter in this case is set by the roof, which slopes from back to front.
Total area on perimeter (T) =front + back + 2 sides
Front area =2.2m x 5.1m =11.22m2
Back area =3.4m x 5.1m =17.34m2
Side area (combined) =2 (2.2 x 2.3) + 1(1.2 x 2.3) =12.88m2
Total area of solids (X) =front walls + back wall + side walls
Front solid =1.6m x 1.0m + 1.8m x 1.0m =3.4m
Back solid =3.4m x 5.1m =17.34m2
Sides solid =2(2.3m x 1.0m) =4.6 m2
X =25.34 m2
Totals area of gaps (space) to open air (Y) =T- X =41.44 m2 – 25.34 m2 =16.1 m2 Y=16.1 m2.
Expressed as %, X (solid) is 61 % of the smoking structure and Y (space) is 39%, so Y is not at least 50% of the structure. So the structure is “substantially enclosed” and smoking could not be allowed.
The owner, to make the structure comply, removed two complete panelled sections from front and side and half of further panelled section of the front. Solid material removed to equivalent of 4.9 m2, so X =20.44 m2 and Y =21 m2.
Expressed as %, X (solid) is 49.3 % of the smoking structure and Y (space) is 50.7%, so Y is now at least (exceeds) 50% of the structure. So the structure is not “substantially enclosed” and smoking could be allowed.
B&NES Council would like to thank South Ayrshire Council for the use of this worked example
We would strongly recommend that you provide similar calculations for your smoking shelter if you require advice on compliance with the 50% rule. Please also bear in mind that planning applications take approximately 8 weeks (if objected to then allow another 4 weeks for a committee hearing).
Alternatively, you may wish to consider temporary structures before going to the expense of building; examples include: awnings, jumbrellas and parasols.
Whether you decide to provide permanent or temporary structures you may also need to consider any/ all of the following:
- Conditions of existing License/ Certificate
- Planning/ Building Control
- Listed Building Consent – (signage, stub plates & litter bins)
- Noise/ nuisance problems.
If in doubt please ask
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