Definition of development

Development is defined under Section 55(1) of the Town and Country Planning Act 1990 as "the carrying out of building, engineering, mining or other operation in, on, over or under land, or the making of any material change in the use of any building or other land."

Section 55(1A) states that “building operations” includes:

• Demolition of buildings;
• Rebuilding;
• Structural alterations of or additions to buildings; and
• Other operations normally undertaken by a person carrying on business as a builder

The Act also specifies what does not constitute development such as:

1. the carrying out for the maintenance, improvement or other alteration of any building of works which:
   1. affect only the interior of the building, or
   2. do not materially affect the external appearance of the building

The term ‘material change of use’ is not defined in the Act. In some instances, determining what constitutes a material change of use is not straight forward but should always be judged as a matter of fact and degree taking into account the individual merits of the case. For a change to be material, the new use must be substantially different from the preceding use.