On 28/01/2019 18:50, Lester Caine wrote:
On 28/01/2019 18:24, Will Phillips wrote:
There are certainly occasions when the street name is needed. For
example, I recently surveyed a single postcode (DE72 2HP) containing
two houses with the same house name, but different street names.
Postcodes do sometimes cover two streets in rural areas. In these
cases one might technically be a subsidiary street, but it's often not
obvious which one.
One could say that DE72 2HP is breaking Royal Mail's own rules, but it
is a rare exception to the rule, and often you find the street is
actually the secondary build reference rather than the street in the raw
data.
It isn't breaking a rule. The rule is that unit + street + postcode is
the minimum required for an unambiguous postal address, as far as
standard postcodes are concerned (large user postcodes are different, of
course, but they, too, are a minority).
It is often the case that a postcode only covers a single street. But
that's by no means universal, and it certainly isn't rare that it covers
more than one.
Bear in mind that the whole point of the postcode system is to
facilitate the delivery of post by Royal Mail. The final two characters
of a postcode are the "walk" - literally, the smallest unit of the
postman's round. And if there happens to be a pair of short streets, or
a short street off a longer one, then they are often incorporated into
the same walk. Topologically, this is the most common walk:
-----------------------------
but this is a common one, too:
---------------------------
|
or this:
|
|----------
|
If the "vertical" section has a different name to the horizontal
section, then it will typically also have duplicate numbering. Which
means the street name is necessary to disambiguate.
I've just had a look at the Land Registry price paid data for my
postcode area (WR), and there are 364 postcodes within it that are
associated with more than one street name. That's a not a trivial or
ignorable number, by any means, even if it is only a minority of
postcodes. To guarantee a completely deliverable postal address, you
need the street name.
Mark
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