Before buying a building site, check its planning status (existing permission, refusals, or none), whether it has a valid site suitability assessment for wastewater, road access and services, and its zoning under the local development plan. Sites sold “subject to planning permission” carry particular risks that should be reflected in the contract terms.
A building site should be assessed on whether it already has planning permission, has previously been refused, or has no planning history at all. If permission exists, check the conditions attached, whether it has commenced (permissions typically last five years), and whether it matches your intended house design and size. If none exists, review the zoning and any Local Area Plan policies that will guide whether an application is likely to succeed.
For sites without a public sewer connection, a satisfactory site suitability assessment, including a percolation test, is essential before a septic tank or other on-site wastewater treatment system can be approved; a failed test can significantly limit or prevent development. Also check road access, sightlines at the site entrance, and whether the local authority requires improvements to an existing access as a condition of any permission.
Confirm services availability, including water supply and electricity connection points, and check for any easements, wayleaves or shared accesses that cross the site. Where a site is being sold subject to planning permission, understand exactly what that phrase means in the specific contract, since it can shift financial and timing risk in different ways depending on how it's drafted.