Is renovation the same as construction?

Renovation is a type of construction, but it is not the same as building new. New construction starts from a cleared site: foundations, frame, roof and services all installed fresh. Renovation works inside an existing shell, keeping the structure, often the staircase, chimney breasts and main walls, and upgrading around them.

The practical difference is the unknowns. On a new-build site you know what is in the ground because you put it there. On a 1930s semi in Bromley or a Victorian terrace in Sydenham, you find out what previous owners did when you open up a wall. We have found chimney breasts removed with no support, lintels missing over widened openings, and joists notched to nothing for old pipe runs. A renovation programme has to leave room for that. A new-build programme does not.

Renovation also means keeping the building weathertight, and often the family living in it, while the work happens. That sequencing is a skill in itself. Both types of work fall under the Building Regulations and both need proper structural design where structure changes, so the paperwork is similar even though the site conditions are not. The advantage of renovating rather than rebuilding is that you keep the bones of the house, and in most London streets those bones are better than anything that would replace them.