Hi Owen,
I found a similar question elsewhere:
Q. "When looking at the rows of houses on East End ordnance maps, is there a
general rule re numbering ? IE, Even on the left, Odd on the right (vice
versa?) or no rule? Advice appreciated".
A. "No real rule, and it very much depends on the date, the amount of
alteration in roads locally (and building of railways and large
buildings)
Often roads were originally numbered down one side and up the other.
Then, because extra houses were added at the end of some streets, there
may have been a change from this to all evens on one side, all odds on
another. On the whole, this was done before 1861 or at least 1871. The
enumerator's walk at the front of a census book will (you hope) state ' a
house 2-32 in Long Lane' 'all houses comprising 1 to 53 in Long Lane '
- they can be in totally different enumeration books, since census walks
in London and other towns were done in blocks, a bit a main road and the
adjacent side roads (or even one side of them).
However, most London streets were subject to great alterations.
Railways were built, main roads were widened, which meant that the ends
of side roads were cut down and the first house or two vanished, so the
remaining ones could be renumbered, and 5 became 1 and so on.
In another common change, two short roads on either side of a crossing
road joined up and became known by the name of one of them, so that all
the houses in Pine Street were now numbered as Acacia Road. So you can
never be totally sure that your Number 6 Acacia Road in 1891 is the same
house numbered 6 Acacia Rd in 1914, or the same as 6 Acacia Rd now. If
you are trying to locate a specific house, it can be quite a long
business, involving directories, rate books, street name changes etc.
Often the give-away is that the fixed points, like churches, pubs,
schools, seem to 'move' into a different street".
I hope this helps.