As someone who inherited a bad extension, I asked the pros whether it's ever worth improving one or if it's better to just start over

Exterior shot of the rear of a brick house with a single storey kitchen extension.

When done well, an extension project can not only transform the way you live in your home, but also enhance how it looks, as well as adding to its overall value. However, a bad extension is another matter entirely.

Bad extensions range from those that were poorly constructed at the time they were built – such as the single-skin brickwork kitchen lean-to, complete with corrugated plastic roof, affixed to my own house when we moved in – to those that feature a number of design faults, as well as structures that just haven't stood the test of time.