Updated: Oct 2, 2017
What are they? How are they formed? What are they used for?
What is a Land Parcel?
A Land Parcel (#LandParcel) is a defined extent of land. Land is three dimensional. Its two-dimensional extent is normally defined planimetrically and, by default, is assumed to include airspace, surface and subsurface. The third dimension, where necessary, is defined descriptively (e.g. railway in tunnel) or using a concept such as stratum (e.g. subsoil, 1st floor), or by elevation/height values although these are not generally available (yet).
How are Land Parcels formed?
When looking at land with a view to performing land assembly, there are many aspects of data which enable definition of useful parcels of land - on their own, or in combination, e.g.:
Possession - a highway and its associated footways and verges may be in the possession of the highway authority. A factory and unused adjacent land may be in the possession of a landowner;
Use - the extent land in the same use, for example, woodland or a group of houses;
Occupation - in a group of houses each one is likely to have a different occupier;
Ownership - legal estates and interests in land are of limited extent;
Homogeneous ownership – where legal estates or interests overlap their intersection(s) define an extent of land with homogeneity in terms of legal estates and interests.
In the early stages of land assembly ‘Land Parcels’ are often defined using observable data such as occupation. As land assembly progresses, and reliable information relating to legal estates and interests becomes available, ‘Land Parcels’ are frequently defined with reference to legal estates or homogeneous legal estates - sometimes also taking into account use and occupation.
Take for example a freehold estate:
part of which is subject to a leasehold estate:
The intersection of these estates creates two parcels:
Parcel 1 contains part of the freehold – Parcel 2 contains part of the freehold and the leasehold.
As a matter of definition changes affecting the extents of source data will result in change to 'Land Parcel' extents. Different types and versions of 'Land Parcels' can be cross-referenced by spatial intersection.
What are Land Parcels used for?
Parcels are used as units of report; for example, to provide spatially referenced schedules of landowners for consultation purposes. They can also be used to identify the spatial extent to which information relates, for example, estimates of acquisition costs.