We’re standing in a small, bright lobby on the other side of a pair of heavy timber and glass doors which lead off the Science Museum’s main entrance hall. Had we not paused to give our names to an attendant at a desk on the left we would have barely noticed this liminal space as we carried straight on up the steps into the museum’s large new supporters’ “salon”.

The route to this spectacular space is visually simple and intuitive but that is only thanks to months of patient design development by the architects, Hat Projects, and their team. The parquet floor and white walls of the 8x8m lobby bely the fact that where we are standing was previously a forgotten bit of undercroft encrusted with bird droppings. It took careful interrogation of the brief and the construction of numerous models before they worked out how this dead end between two buildings could provide a seamless link to the new Smith Centre.

The situation was complicated by multiple level changes and by the fact that parts of the site were owned by Imperial College. By the time Hat was appointed through a competition, lengthy negotiations had resulted in a land swap. The university got an Edwardian Royal Mail office (where the Smith Centre was previously located) while the museum got the sorting office behind – or most of it: one bay was retained by Imperial, along with a chunk of the basement.

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