The crisp white houses on Lansdowne Crescent were built between 1860 - 1862 by the Wyatt family, a prominent architectural firm at the time. The gap between numbers 28 and 29 had existed since the houses were built, and though no-one seems to know the purpose of the gap, it is thought to have been intended for an entrance stair to access the communal gardens behind the crescent.

Narrower than the neighbouring houses, each with a frontage of around 22 feet, the gap between 28 and 29 was a mere 13 feet and 2 inches. To maximise the space between the houses, the exposed party walls on either side were left bare.

The site was identified by the architect and his family whilst dropping their children off at the local Montessori school. It had belonged to an interior designer called Roland Whiteside, who had bought the site after purchasing the neighbouring house (number 29) and gained outline planning permission in 1963 for a 'dwelling house comprising a basement, ground and three upper floors with a built-in garage', with provisos and about height, massing and materials, amongst other matters.

Once the site was acquired, Jeremy Lever began sketching designs and building bolsa wood models for the proposed house. Lever's first designs (one of which is pictured here) were rather cautiously made, keeping to the traditional terrace formula of a stair to one side with two rooms on each floor, referred to historically as a 'one pair floor'.

The Lever family soon decided that, despite all the traditional advantages, they did not want the standard terrace house layout. After a tentative beginning, there was a strong desire to move away from the traditional vernacular of the houses on the crescent, and view the infill house as a 'hinge' between the houses on each side that fan out in a mirror image of one another. It soon was clear that the design of the front elevation should be a well-mannered 'mask' but definitely not a reduced facsimile of the 1860s houses of the crescent, while the rear elevation would be as freely designed as possible.

The greatest challenge was a dimensional one, with a width of only 13 feet and 2 inches tapering by 6 inches towards the top as the neighbouring houses lean inwards over time. The breakthrough in Lever's design came with the realisation that working with multi levels offered a scope for a more imaginative solution and a way of achieving the maximum internal and external space. The overall result, after much calculation and difficulty, was a building with six storeys at the front and seven storeys at the back. Or, as Lever liked to describe it, the model had two and a half floors at the top and two and a half floors at the bottom, with an intermediate floor that is split level and double in height.