Solved my riddle, at least to the extent that I needed to! Permanent
provision for access onto most roofs over 4.5 m above ground required as far
back as 1971 and probably before. 4.5 m was probably 15 feet in earlier
legislation prior to the various regulations which came in to metricate requirements.
The Building Standards (Scotland) Regulations 1981
www.legislation.gov.uk/uksi/1981/1596/contents/made
”P7 Access to roofs
Where in the
case of any building-
(a)
the
roof is a mansard roof and the flatter portion thereof is; or
(b)
the
roof is a flat roof and is; or
(c)
the
roof is neither a flat roof nor a mansard roof and the eaves are,
at a height of more than 4.5 metres
above ground level at every part, the building shall be provided with suitable
means for obtaining access to the roof and to any chimney stacks forming part
of the building:
Providing that nothing in this regulation
shall apply to buildings of occupancy sub-group A1 or A2 not exceeding two storeys
in height.”
This regulation replaced identical wording in regulation F31
of The Building Standards (Scotland) Consolidation Regulations 1971. I’ve not traced
the requirement further back.
The Building Standards (Scotland) Amendment Regulations 1986
https://www.legislation.gov.uk/uksi/1986/1278/contents/made
“32 – (1) Regulation P7 shall be deleted.”
So suddenly it was OK to design any building with a roof more
than 4.5 m above ground without thinking about permanent means of access for
maintenance etc.
Eventually this decision was reversed, but only in part.
Current standard in Scotland for most housing is set out in “Building
Standards technical handbook 2017 : Domestic buildings”
https://www.gov.scot/publications/building-standards-2017-domestic/
Standard 4.8
Every building must be designed and constructed in such a way that:
a. p….
b. f….
c. b….
d. a safe and secure means of access is provided to a
roof, and
e.
Limitation:
Standard 4.8(d) does not apply to domestic buildings.
The equivalent handbook for non-domestic buildings exempts
those with roofs not more than 4.5 m above the ground (i.e. retaining the old
standard).
Not checked exactly when the deregulatory measure in 1986 was
reversed, nor why anyone thought it logical to exclude domestic buildings
(which exclude premises such as the sleeping accommodation in prisons and care
homes)