NLPG Guidance Document 1: Developing and ... - Iahub.net

Produced by Intelligent AddressingnlpgNLPG Guidance Document 1:The NationalLand & Property GazetteerDeveloping and implementing a LLPG froman extract from the NLPG

This guidance document, issued by the NLPG Custodian, is essential reading for all localauthority land and property gazetteer custodians. It aims to raise awareness of themethodology that needs to be put in place to ensure that a local land and propertygazetteer (LLPG) is both kept up-to-date at the local level and also in synch with thenational dataset. More importantly this document aims to assist a local land and propertygazetteer custodian in implementing and developing a LLPG based on an extract from theNLPG.For any LLPG custodian an understanding of BS7666 (2000) is required. It is alsoessential that you are familiar with the NLPG Data Transfer Format (DTF) and the generalprinciples behind the benefits of creating and maintaining a LLPG and its importance withinthe NLPG. It is advisable that you seek confirmation from software suppliers and dataconsultants involved in any part of your LLPG that they are also incorporating BS7666 intotheir LLPG platforms or that any data cleaning/matching processes will facilitate your localauthority's participation in the NLPG. For an up-to-date list of accredited software suppliersplease see the NLPG web site www.nlpg.org.uk for more information. IDeA are also in theprocess of accrediting data consultants offering address cleaning/matching services toascertain their compliance with the whole BS7666 LLPG creation process and ability to linkto NLPG.BackgroundThe NLPG has now been created for England and Wales and is being used by theNational Land Information System (NLIS) to automate the search aspect of theconveyancing process. The NLPG is made up from two distinct sources which have beenmerged and matched together to form its composite structure. These sources are:(i)(ii)existing local authorities that have submitted their own BS7666 compliant LLPGs tothe NLPG hubnational datasets provided by the Valuation Office (Council Tax and Non DomesticRates); ADDRESSPOINT for some co-ordinate information; the National StreetGazetteer, and a commercial property gazetteer provided by Property IntelligencePlc.Those local authorities that successfully submitted their own LLPGs to the first build ofNLPG were able to retain any existing Unique Property Reference Numbers (UPRNs) usedin their gazetteers. The remaining part of the national dataset has had UPRNs allocated toeach of the BLPU entries by the NLPG custodian. One of the fundamental aspects to theworkings of the NLPG is the UPRN. These numbers are unique across England andWales and now that the NLPG is being used by other organisations, are fixed and will notchange over time. If a property or land parcel ceases to exist the respective UPRNassociated with the property will simply be 'closed' or marked for deletion and thenarchived. This means that the same UPRN will not be used and possible future duplicationis avoided.NLPG Guidance Document 1 v1.3 April 20031

First Steps to obtaining your NLPG extractFor many local custodians a LLPG and its subsequent link to the NLPG isconnected with Best Value and addressing e-government targets for citizencentred service delivery. Consequently the development of a definitive index ofplaces within a local authority administrative area is of importance in identifyingways of improving service delivery and meeting these Best Value targets. Thisprocess is something that the Improvement and Development Agency for LocalGovernment (IDeA) through the Local Government Information House (LGIH) arekeen to measure.Consequently, in order to release the data to you your authority will need to havesigned and returned the NLPG Licence Agreement between LGIH and your localauthority. This licence agreement was sent to the Chief Executive of all District,Metropolitan and Unitary Authorities in August 2000. If your local authority hasnot signed this agreement or you require another copy please contact StevenBrandwood at IDeA (steven.brandwood@idea.gov.uk or tel 020 7296 6615) .Data FormatThe extract of your local authority LLPG from the NLPG will be supplied to you inthe NLPG Data Transfer Format. This is a BS7666 compliant data specificationtherefore any software application you are using must be able to support a file ofthis nature. You can specify that the data be supplied to you in either DataTransfer Format version 5.3 or version 6.3.Note - a copy of the relevant data transfer format specification is supplied on theCD ROM with a copy of your NLPG extract. Alternatively a copy is available todownload from the NLPG web site.Important Information for LLPG Custodians1. Retention of UPRNSAs the UPRNs contained in the NLPG are already in use by other third partiessuch as NLIS and its associated partners, the UPRNs contained within the NLPGextract need to be retained in any subsequent LLPG your authority creates. Youmay undertake this by maintaining a simple cross-reference table between thenational UPRN and your own referencing number; renumbering other applicationdata with the UPRN from the NLPG; or by adding a UPRN field into existingapplications and populating this field with the corresponding NLPG UPRN.Similarly the addresses/BLPUs that these UPRNs are allocated to need to beretained, i.e. it is not possible to renumber BLPUs with a different UPRN albeitwithin the same UPRN range supplied in the extract you have. For example thedata contained within the NLPG for your local authority area may contain anumber of BLPUs and associated records within the number range 23000001 to23500001. Each of these numbers will be associated to differing 'addresses'.For example the following LPI entry may occur,NLPG Guidance Document 1 v1.3 April 2003 2

UPRN 23000001SAONFIRST FLOOR FLATPAONALPHA HOUSEUSRN(street) 4013453(Church Street)Any data that you match to this address (for example Flat A, Alpha House or Flat 1, AlphaHouse) must retain this UPRN of 23000001. In this case two alternative LPIs will then becreated for this BLPU both with the same UPRN. Likewise it is not possible to takeanother number in the number range and allocate the UPRN of say 23111112 to thisBLPU/address.Therefore you need to use the NLPG dataset as the basis to match other applicationdatasets to and not simply extract the UPRN range.2. Street DataThe extract from the NLPG for your local authority area may contain a number of LPIsthat have been matched to temporary USRNs. These USRNs all have the USRN prefix of'77' and reference streets that cannot be located in the National Street Gazetteer for yourarea. A requirement of BS7666 is that all BLPUs are referenced to a street. Thereforerather than omit these BLPUs from your dataset the associated streets have beenassigned a temporary value/entry in the NLPG.You will need to resolve any occurrences of the temporary USRNs during your datamatching/cleaning exercise. As much information as possible has been retained for eachBLPU/LPI in terms of street descriptor, locality, town and county etc, but where there is noidentifiable street descriptor a generic street name has been generated, i.e. "unspecifiedstreet or streets within the locality of….". After investigation where it is found the entry isclearly a new street that needs to be entered into the NSG you will need to assign a newUSRN from the given range allocated to your authority. Note - this function is undertakenby your Highways Department at the County level for District Authorities.The relevant status/change records will then need to be created and submitted to theNLPG reflecting the new street entered into the NSG and any associated LPIs will needtheir USRN value modified to reflect this change.3. Subsequent additions to your LLPGAfter you have used your NLPG data extract to match other datasets to you may find thatyou need to add new BLPUs to this dataset, i.e. insertions to what is currently in theNLPG for your area. In order to retain the integrity of the NLPG you will need to request arange of new UPRNs from the NLPG custodian so that you can be sure that you are notduplicating numbers currently being used by other local authority custodians.A request can be sent via email to uprn@nlpg.org.uk or contact the custodian on 0207484 3766.Please note that a block of new UPRNs issued by the NLPG custodian may not becontiguous with your existing UPRN range.NLPG Guidance Document 1 v1.3 April 20033

4. Re-supply of revised LLPG data for incorporation into NLPGThe NLPG extract you receive from the NLPG custodian is a live copy of the data foryour local authority area. It is currently being used in the NLIS process and thereforereturning this data in its verified form needs to be in the NLPG data transfer format.Where changes have been made to the data supplied to you as a result of datacleaning and matching processes these need to be identified in the subsequentresupply to the NLPG.There are a number of record change types that you need to be aware of. Change typedescribes the status of a street or land and property gazetteer record.The following change types are valid:CDISChangeDeletionInsertStatusWhen a record, which is new to a data provider, is being transferred it will be flagged asInsert. This record represents a record that is over and above what is currently in theNLPG for your local authority area, e.g.21,123457,"I",222234,567853,1010,20010513,,1,1,"..L","N",20011513,20010513,1Where a change is to be made to an entry, a Status record will first be submitted. Thisis an exact copy of the record already in the Local Street Gazetteer/LLPG. It isimmediately followed by a Change record, which will record both the changed andunchanged information, e.g.21,123456,"S",111111,555555,1010,20001214,,4,1,"…L","N",20001214,20001214,221,123456,"C",111231,555231,1010,20001214,,1,1,"…L","N",20010201,20001214,3The NLPG can use the Status record to identify exactly which record is to be altered,and then compare the Status and Change records to detect what has changed. If theStatus record does not match the corresponding record in the NLPG it will be ignoredand a reject report generated.A record marked for deletion indicates that the record has been put into yourLLPG/NLPG in error (for example possible duplications of the same address) and youwish it to be removed from the NLPG. A Delete status within a record will contain thewhole record content to be deleted and this too will be the subject of a comparison withthe corresponding NLPG record prior to deletion, e.g.21,124563,"D",321234,786943,1010,20001214,8,2,"…L","N",20001214,20001214,4NLPG Guidance Document 1 v1.3 April 20034

If a Status record is submitted with no corresponding Change record then this willbe taken by the NLPG as an instruction to compare the local with the nationalrecord and to report any differences.- IMPORTANT NOTE -Before you start matching other datasets to your NLPG extract please make surethat you are able to track any changes you make to the NLPG extract so that therequired transfer file can be resubmitted to the NLPG custodian. If you arepassing on this function to another data consultant please make sure that they areable to produce the necessary output file (to include status/change pairs) in anywork that they undertake on your behalf. Failing to do this may mean that you willhave trouble resubmitting data for inclusion into the NLPG and may also have toundertake the matching process again to ensure that an audit trail is produced tocreate the correct transfer file. Please contact the NLPG custodian should youneed any further advice.Next stepsOnce you have matched your application data to the NLPG extract and created arevised LLPG for your local authority you will need to submit this to the NLPG.You can submit this via email or on CD ROM to the NLPG.Please zip down any files sent via email and send to llpgupdate@nlpg.org.uk.Alternatively please send your updates to:Simon BarlowNLPG CustodianIntelligent Addressing Ltd13-15 John Adam StreetLondonWC2N 6LUFuture options that are currently in the process of being set up to enable a moreautomated delivery mechanism include an ftp site and direct communication linksto the NLPG Hub. More details will follow for all LLPG custodians.NLPG Guidance Document 1 v1.3 April 20035