How much does a house extension cost?

As a general guide, single-storey extensions in and around London typically start from £2,500 to £3,000 per square metre for a good-quality build, but this is excluding the costs of kitchens, bathrooms and the ever-dreadedVAT.
Two-storey extensions tend to offer better value per square metre because you’re doubling the space over one set of foundations and under one roof. We provide itemised, fixed-price free quotations so there are no surprises.