Page 1 of 1
NLPG - A coordinate(d) hub

Gayle Gander
Head of Marketing
Intelligent Addressing
London
ggander@intelligent-addressing.co.uk
Local authorities in UK have a statutory responsibility
to create all addresses. However, those authorities
did not hold a unified list of addresses until NLPG
rationalised databases across the authority
The National Land and Property
Gazetteer (NLPG) is the
definitive, national address
list that provides unique identification
of land and property and conforms
to the British Standard, BS
7666. Updated on a continual basis
by each local authority, the NLPG
covers the whole of England and
Wales and contains more than 30
million residential, business and nonmailing
addresses.
Local authorities have a statutory
responsibility for creating all addresses.
However, until the advance of the
NLPG, those same local authorities
did not hold a unified and consistent
list of addresses within their areas.
This led to various services within
individual local authorities maintaining
separate and incompatible
address databases. It was quite normal
to find that across a local authority,
a single property may have many
different variants in numerous data-
bases and so be referred to in many different
ways. The aim of the NLPG was to rationalise
these databases right across the authority.
NLPG is a central repository or "hub" for all
LLPGs and coordinates the 376 LLPGs created
by local authorities. It also enforces the compliance
of all LLPGs with the national standard
for the representation of address information,
BS 7666 Parts 1 and 2, to ensure data format
consistency across the countries. Each record
has a unique property reference number
(UPRN) which provides a reference key to join
related address records across different
datasets.
NLPG ARCHITECTURE
The Mapping Services Agreement enforces the
compliance of all LLPGs with the national
standard for the representation of address information,
BS7666:2006 Parts 0, 1 and 2 to ensure
data format consistency across the countries.
Each gazetteer entry has an unchanging centrally
managed Unique Property Reference
Number (UPRN) which provides a reference
key to join related object records across different datasets.
Postcodes, which are invaluable to many, may change.
Even if a property is demolished, the UPRN can never be
reused & retains this historical information. In order to
fully and efficiently represent the required information,
the BS7666:2006 data structure relies on a relational system
of streets, Basic Land and Property Units (BLPUs)
and Land and Property Identifiers (LPIs). BLPU represents
the real world objects recorded within the gazetteer
and can be thought of as relating to "properties" or "locations".
Land and Property Identifiers are labels used to
identify a BLPU in a meaningful way and can be thought
of as relating to "addresses". An LPI must be referenced to
a single BLPU and one or more streets which provide
access to the object in question.
Multiple addresses
One of the main advantages of NLPG and BS 7666 data
model is that it supports the inclusion of multiple
addresses for a single location. Each BLPU can be referenced
to an approved address (LPI) but may also have any
number of alternative, provisional or historic addresses
which will aid cross-organisation address identification.
As all of these records are referenced back to the same
UPRN, this facilitates the linking of asset and application
data to the same identifier.
Objects without postal addresses (OWPAs)
Usually, when people consider addresses, they think purely
of residential properties or properties which receive
mail. However, in addition to comprehensive sets of these
records, the NLPG scope extends far beyond this and
includes many OWPAs.
'Parent-child' relationships
Many locations that are within the scope of the gazetteer
comprise of a number of subdivisions or sub-buildings.
This may happen "vertically" (for example in a block of
flats) or "horizontally" (for example in a hospital complex
with many different buildings). The complete block or
site is known as the "parent record" and all of the subdivisions
are known as the "child records". NLPG captures all
of this information. In each case, there is one gazetteer
entry for the parent record in its own right and one for
each of the child records.
Usage of the NLPG
NLPG is used extensively by local authorities throughout
England and Wales to underpin service delivery across a
range of departments including planning, Council
tax, electoral roll, estates, local land charges, non-domestic
rating list, housing, fire and police, building
control/development control and customer relationship
management.
A number of police authorities have taken NLPG data in
order to evaluate the possibility of using the dataset as
their trusted data source. The British Transport Police is
moving to a single corporate gazetteer, based on the
NLPG to link all of its systems.
BENEFITS OF NLPG
The NLPG brings intangible as well as tangible financial
benefits. Intangible benefits have been evaluated through
a study prepared by CEBR (2006). There is evidence of
savings in excess of £ 50m per annum. In terms of tangible
benefits: Plymouth identified savings of around
£150,000 pa simply by avoiding the duplication of
addresses; Huntingdonshire increased tax receipts by
around £180,000pa. The CEBR estimated a saving of £ 54
million annually to those who create the data and £ 40
million for those who could potentially use the data across
local governments. Social benefits include enhanced customer
services, improved customer experience and
improved community safety.
An example of environmental benefits is in the optimisation
of the routes for refuse collection vehicles. One
local authority has quantified a saving of one vehicle,
which not only saves pollution but also £100,000 per
annum. Nationally there is great interest in the dataset
from in-car navigation systems providers whose information
at present is incomplete and out of date, resulting in
many wasted and frustrated vehicle movements.