1. Building regulations
Ensure your plans conform to building regulations. You can usually submit your application online at your local council’s website. Visit Planningportal.co.uk/buildingregulations.
2. Structural engineer
If thinking about a single-storey extension now, but adding a second storey later you will need a structural engineer (find one via istructe.org) to establish whether the foundations and walls are strong enough to support extensive future works.
3. Structural alterations
Before you knock down a wall, check with a suitably qualified and experienced professional whether it is load bearing and if any structural alterations are required first, such as installing a new load-bearing beam in steel, concrete or timber.
4. Party Wall Notice
In England and Wales, if your project involves any excavation or alterations on or near a neighbour’s boundary, including shared structures like party walls or floors, check if you are legally required to issue a Party Wall Notice. Visit the Planning Portal for advice, before starting work.
Think about how the new extension will affect the light in the existing adjoining room, and if the addition of roof windows or sun pipes will help to make both spaces brighter.
Featured image: John Boon and Susanna Frediani extended their home to create an open-plan New York loft-style kitchen