We’ve all fantasised about doing it – taking a building that’s rundown and unlovely, and transforming it into something spectacular. It feels like the ultimate creative project. Only there are practical benefits, too, as it’s one of the few ways to ensure you end up with a house built to your exact specifications. But what are the practicalities of undertaking such a project? How do you actually go about doing it?

What one Wandsworth family did was to engage the services of Battersea-based practice And Architects, who, having done around 300 similar projects across London, have some experience of this kind of thing. ‘The main change we made was to extend the existing basement, which was very small, and put in a glass floor with roof lights so that the light came down two storeys,’ says Rachel Nogueira, a director at the firm. ‘We then created a link from the basement to the garden, which is important – particularly in a family home.