Technical Booklet E Fire Safety·Page 146·Table 5.4
Permitted unprotected percentages in relation to enclosing rectangles (Method 3)
Table 5.4 specifies the minimum boundary distances required for different percentages of unprotected area on building facades, varying by enclosing rectangle width and height. Separate values are provided for Purpose Groups 1, 2, 3, 5 and 7 (shown in brackets) versus other purpose groups.
Table 5.4 Permitted unprotected percentages in relation to enclosing rectangles (Method 3)
Width of enclosing rectangle (m): Distance from relevant boundary for unprotected percentage not exceeding 20% 30% 40% 50% 60% 70% 80% 90% 100%
Minimum boundary distance (m) – figures in brackets are for Purpose Groups 1, 2, 3, 5 and 7
Enclosing rectangle 3 m high:
3 m: 1.0(1.0) 1.5(1.0) 2.0(1.0) 2.0(1.5) 2.5(1.5) 2.5(1.5) 2.5(2.0) 3.0(2.0) 3.0(2.0)
6 m: 1.5(1.0) 2.0(1.0) 2.5(1.5) 3.0(2.0) 3.0(2.0) 3.5(2.0) 3.5(2.5) 4.0(2.5) 4.0(3.0)
9 m: 1.5(1.0) 2.5(1.0) 3.0(1.5) 3.5(2.0) 4.0(2.5) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.0(3.5)
12 m: 2.0(1.0) 2.5(1.5) 3.0(2.0) 3.5(2.0) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.5(3.5) 5.5(3.5)
15 m: 2.0(1.0) 2.5(1.5) 3.5(2.0) 4.0(2.5) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(3.5) 6.0(4.0)
18 m: 2.0(1.0) 2.5(1.5) 3.5(2.0) 4.0(2.5) 5.0(2.5) 5.0(3.0) 6.0(3.5) 6.5(4.0) 6.5(4.0)
21 m: 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.0(4.5)
24 m: 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(3.5) 7.0(4.0) 7.5(4.5)
27 m: 2.0(1.0) 3.0(1.5) 4.0(2.0) 4.5(2.5) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.0(4.0) 7.5(4.5)
30 m: 2.0(1.0) 3.0(1.5) 4.0(2.0) 4.5(2.5) 5.5(3.0) 6.0(3.5) 6.5(4.0) 7.5(4.0) 8.0(4.5)
40 m: 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 5.5(3.0) 6.5(3.5) 7.0(4.0) 8.0(4.0) 8.5(5.0)
50 m: 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 6.5(3.5) 7.5(4.0) 8.0(4.0) 9.0(5.0)
60 m: 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 7.0(3.5) 7.5(4.0) 8.5(4.0) 9.5(5.0)
80 m: 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 7.0(3.5) 8.0(4.0) 9.0(4.0) 9.5(5.0)
No limit: 2.0(1.0) 3.0(1.5) 4.0(2.0) 5.0(2.5) 6.0(3.0) 7.0(3.5) 8.0(4.0) 9.0(4.0) 10.0(5.0)
Enclosing rectangle 6 m high:
3 m: 1.5(1.0) 2.0(1.0) 2.5(1.5) 3.0(2.0) 3.0(2.0) 3.5(2.0) 3.5(2.5) 4.0(2.5) 4.0(3.0)
6 m: 2.0(1.0) 3.0(1.5) 3.5(2.0) 4.0(2.5) 4.5(3.0) 5.0(3.0) 5.5(3.5) 5.5(4.0) 6.0(4.0)
9 m: 2.5(1.0) 3.5(2.0) 4.5(2.5) 5.0(3.0) 5.5(3.5) 6.0(4.0) 6.0(4.5) 7.0(4.5) 7.0(5.0)
12 m: 3.0(1.5) 4.0(2.5) 5.0(3.0) 5.5(3.5) 6.5(4.0) 7.0(4.5) 7.5(5.0) 8.0(5.0) 8.5(5.5)
15 m: 3.0(1.5) 4.5(2.5) 5.5(3.0) 6.0(4.0) 7.0(4.5) 7.5(5.0) 8.0(5.5) 9.0(5.5) 9.0(6.0)
18 m: 3.5(1.5) 4.5(2.5) 5.5(3.5) 6.5(4.0) 7.5(4.5) 8.0(5.0) 9.0(5.5) 9.5(6.0) 10.0(6.5)
21 m: 3.5(1.5) 5.0(2.5) 6.0(3.5) 7.0(4.0) 8.0(5.0) 9.0(5.5) 9.5(6.0) 10.0(6.5) 10.5(7.0)
24 m: 3.5(1.5) 5.0(2.5) 6.0(3.5) 7.0(4.5) 8.5(5.0) 9.5(5.5) 10.0(6.0) 10.5(7.0) 11.0(7.0)
27 m: 3.5(1.5) 5.0(2.5) 6.5(3.5) 7.5(4.5) 8.5(5.0) 9.5(6.0) 10.5(6.5) 11.0(7.0) 12.0(7.5)
30 m: 3.5(1.5) 5.0(2.5) 6.5(3.5) 8.0(4.5) 9.0(5.0) 10.0(6.0) 11.0(6.5) 12.0(7.0) 12.5(8.0)
40 m: 3.5(1.5) 5.5(2.5) 7.0(3.5) 8.5(4.5) 10.0(5.5) 11.0(6.5) 12.0(7.0) 13.0(8.0) 14.0(8.5)
50 m: 3.5(1.5) 5.5(2.5) 7.5(3.5) 9.0(4.5) 10.5(5.5) 11.5(6.5) 13.0(7.5) 14.0(8.0) 15.0(9.0)
60 m: 3.5(1.5) 5.5(2.5) 7.5(3.5) 9.5(5.0) 11.0(5.5) 12.0(6.5) 13.5(7.5) 15.0(8.5) 16.0(9.5)
80 m: 3.5(1.5) 6.0(2.5) 7.5(3.5) 9.5(5.0) 11.5(6.0) 13.0(7.0) 14.5(7.5) 16.0(8.5) 17.5(9.5)
100 m: 3.5(1.5) 6.0(2.5) 8.0(3.5) 10.0(5.0) 12.0(6.0) 13.5(7.0) 15.0(8.0) 16.5(8.5) 18.0(10.0)
120 m: 3.5(1.5) 6.0(2.5) 8.0(3.5) 10.0(5.0) 12.0(6.0) 14.0(7.0) 15.5(8.0) 17.0(8.5) 19.0(10.0)
No limit: 3.5(1.5) 6.0(2.5) 8.0(3.5) 10.0(5.0) 12.0(6.0) 14.0(7.0) 16.0(8.0) 18.0(8.5) 19.0(10.0)
Source — /Users/richardhill/Documents/planning-arch-project/data/documents/regional/Technical Booklet E - Fire Safety.pdf