As you find it now, Somerset House is an exercise in reclamation from a government bureaucracy that filled its interiors with dreary offices and its courtyard with dozens of parked cars. Without the Parisian grand projet as examplars, it might never have happened.
Somerset House was originally designed by William Chambers (1766), built to house the learned societies, government offices and the Navy Board. As the reinvention of a former Tudor palace on the site it was effectively London’s first major public office building and paralleled the quite different Adelphi exercise by the Adam Brothers, just upstream (begun 8 years before). Both schemes straddled a wider River Thames before the Embankments were constructed and enjoyed direct boat access to vaults at the lower level. Access from the Strand was at a much higher level and the difference is still a key part of the experience (e. g. moving from the entry lobby down the flights of stairs to the basement cafe).
The building’s reinvention in the late ‘90’s cleared out the Inland Revenue and its less-than – imaginative use of the central court as a car park, giving the buildings a long overdue grands projet treatment. Dixon Jones were responsible for the excellent fountain court (shades of Parc Citroen in Paris) and the more tentative river terrace (which includes a footbridge link onto Waterloo Bridge). Other parts include the Courtauld Gallery, Hermitage Rooms, and Gilbert Collection (of decorative arts). However, it is regrettable to see much of it sinking back into a stereotypical English mish-mash of half-resolved gestures, situations, and services. The building fabric was handled by Feilden Mawson. Inskip & Jenkins did the Gilbert.
But even if the museums fail to interest you, and the cafes could be hugely improved, the outer river terrace is a fine place to sit and view London; and the inner court is a wonderful place to simply sit and think about space, and classicism and the fine gamesmanship of Chambers. (Each December, the central court hosts an ice-skating rink.)
The Adelphi that the (three) Adams Brothers 20 designed as a speculative venture between 1768 – 74 is apparently lost apart from a few remaining terrace parts. Certainly, the central block which formed what the Pevsner guides call ‘the first great Georgian riverside composition’ is long gone (now an office block from 1936). But the Royal Society for the Arts, Manufacture and Commerce (RSA; John Adams Street) gives us some semblance of what it was all about — particularly if you enter from the Strand side and go down to the lower, vaulted levels of this labryrinthian building.