Property Life Cycle - Merges, Splits and Changes

🏗️ Why Changes Occur

Not all developments follow the simple new-build property model. Over time, buildings and streets may evolve due to:

• Character or ownership changes

• Conversion into multiple dwellings

• Mergers into a single unit

• Demolition and redevelopment

These changes must be correctly managed within the gazetteer to ensure consistency across LLPG and LSG data.

---

🛣️ Streets

• Every LPI (Land and Property Identifier) references a valid street USRN from the Local Street Gazetteer.

• Streets can be merged or split into smaller ESUs (Elementary Street Units), e.g., when new junctions are created.

• Any street change will also update the USRN on linked properties.

🔗 See Street Lifecycle.

---

🏠 Properties

➕ Merge

When multiple buildings or dwellings are combined into one:

• Existing BLPUs are made historical.

• A new BLPU and LPI are created.

• A merge typically occurs when adjacent BLPUs are brought together for uniform occupation, ownership, and function.

• Sometimes, an intermediate development site BLPU is created.

📌 Note: Only the Custodian Authority can amend these detailed relationships.

---

✂️ Split

When one building is divided into multiple units (e.g., conversion into flats):

• Additional records may be required.

• If the original BLPU remains, extra LPIs may be added (e.g., multiple flats behind one front door).

• If independent entrances are created, or a site is subdivided and sold off:

  • The original BLPU becomes historical.

  • Multiple new BLPUs and LPIs are created.

📌 A split occurs when a BLPU no longer represents uniform occupation, ownership, and function.

---

🏚️ Demolition

When a property is demolished:

• The old BLPU(s) become historical.

• If the site is redeveloped, a new BLPU and LPI will be created for the new unit(s).

• An intermediate development site BLPU may also be recorded.

---

🔄 Change in Object

• A BLPU also changes with the nature of the land or property.

• Example: Greenfield land → Development site → Completed buildings.

• The BLPU State Code and Logical Status are used to track these lifecycle stages.