Housing, Town Planning &c. Act, 1909
43. Notwithstanding anything in any local Act or byelaw in force in any borough or district, it shall not be lawful to erect any back-to-back houses intended to be used as dwellings for the working classes, and any such house commenced to be erected after the passing of the Act shall be deemed to be unfit for human habitation for the purposes of the provisions of the Housing Acts.
Provided that nothing in this section-
(a) shall prevent the erection or use of a house containing several tenements in which the tenements are placed back to back, if the medical officer of health for the district certifies that the several tenements are so constructed and arranged as to secure effective ventilation of all habitable rooms in every tenement; or
(b) shall apply to houses abutting on any streets the plans whereof have been approved by the local authority before the first day of May nineteen hundred and nine, in any borough or district in which, at the passing of this Act, any local Act or byelaws are in force permitting the erection of back-to-back houses.
It all comes down to ventilation then. In order to prevent modern back-to-backs being constructed it is necessary to prove that the change of air is below a certain mandatory standard and therefore unhealthy. All the developers would do in this case is to punch holes in the walls and install forced air ventilation to their single aspect flats. They wouldn’t stop building them unless it was made law that no flat could be single aspect.
Please see my page about single aspect flats.
More about Leeds back to backs here:-
The term back-to-back terrace is often taken to mean through terraced homes lying back to back separated by an alleyway or ‘ginnel’. ‘Real’ back-to-backs were built on either side of a spine wall, so they have no rear windows, back doors or back gardens. It is almost 100 years since the Housing and Town Planning Etc. Act 1909 prohibited the building of back-to-back terraced homes. Despite that piece of legislation, which was largely ignored in Leeds until 1938, and the clearance of many back-to-backs during the 1970s, there are still around 19,500 in Leeds.
Back-to-backs are a legacy of the industrial past of Leeds, built cheaply and numerously, to house the workforce needed for the textiles and other manufacturing industries. 100 years on and the role and function of back-to-back housing has changed. Leeds no longer has a large textiles and manufacturing industrial base, and instead has built its recent economic growth on its financial and legal sector, and its future growth will be in the high skill and value ‘knowledge economy’ while there will also be huge growth in jobs in service, retail, entertainment and catering industries.
Addressing the Challenge of the Back-to-Backs in Leeds
Volume 1 – Volume One: Strategy – November 2008
Volume 2 – Volume Two:Background Research – November 2008
A bill was introduced into the Commons in 1841 containing a clause to outlaw back-to-backs. Following sustained opposition by builders (and indeed the Town Clerk of Leeds) on the grounds that rents would have to rise and would be unaffordable to many working class people, driving them into lodging houses, the entire Bill was dropped in 1842.
Back-to-back terraced housing was extensively built during the 19th and early 20th centuries to house the rapidly expanding population attracted to manufacturing and industrial jobs in the city. High density meant higher profits for speculative builders. But a national debate about the house type developed, led by social and health reformers, focusing on the lack of through ventilation, insanitary conditions of shared toilet yards, frequent overcrowding, and lack of other amenities. A number of cities used local powers to stop building back-to-backs.
In Manchester and Liverpool, for example, back-to-backs were banned in 1844 and 1861 respectively; no plans for back-to-backs were approved for Bradford after 1870; and in Birmingham they were banned in 1876. [my emphasis - Ed.]
Here’s what CABE have to say about back to backs in Castleford, Yorkshire:-
Here’s a recent example. Senior industry representatives have told CABE that new back-to-back housing in Castleford, West Yorkshire, is good enough because people are prepared to buy it.
Back-to-back houses have every storey attached to neighbouring homes on both sides and at the back. They have doors and windows only at the front, which apart from anything else can increase fire hazard threefold by restricting options for escape.
The reason that there is a market for back-to-backs, we are told, is that they are cheaper than conventional housing. This is in spite of the fact that the first Town Planning Act of 1909 made them illegal because they were bad for occupants’ health.
These designs were outlawed, and the fact that they can be built more cheaply and sold does not confirm their design quality is good enough.
Rooms can be either naturally ventilated or mechanically ventilated (by fan or other system). Under current regs toilets are required to have a fan even if they also have a window. A dual aspect flat can benefit from cross ventilation and this means that you can have a much deeper plan. There is nothing preventing single aspect flats ventilating effectively as long as there is sufficient window area (ideally both low and high level) and that this is proportional to the floor area and occupancy. Nowadays we measure this through computer analysis.