New River Head (former Metropolitan Water Board offices)

The former Metropolitan Water Board offices at New River Head are built of red and brown brick with Portland stone, beneath slated mansard roofs. Modern uPVC windows have replaced the original timber sashes.

The building forms a large irregular pentagon in plan, comprising a large quadrangle to the west and a triangular extrusion to the east formed by two obliquely projecting wings enclosing a courtyard. The main entrance, in the centre of the south range, leads via a lobby and a broad entrance hall to the former Rental Ledger Hall, which occupies the quadrangle's central well. Principal staircases stand at either end of the west range, with a third stair at the apex of the eastern triangle. The boardroom occupies the first floor of the south range immediately above the entrance, while the Oak Room is on the first floor at the south end of the west range.

Exterior

The south front to Hardwick Street is a bold Beaux-Arts Classical composition, with a three-bay stone-faced centrepiece flanked by narrow recessed bays and projecting outer wings. The wings are faced in fine red brick, though the rusticated stonework of the lower storey is carried across the whole front. The central doorway is set in a richly ornamented surround, its upper panel containing a wreath with the MWB monogram and an inscription ('ERECTED BY THE METROPOLITAN WATER BOARD ON THE SITE OF THE NEW RIVER HEAD') set amid naturalistically carved water-plants and scrolls bearing the dates 1613 and 1920. The doors themselves are clad in bronze and bear MWB monograms in paterae with anthemions. The piano nobile, which contains the boardroom suite, has paired giant pilasters to the centrepiece and stone balconies and pedimented architraves in the outer wings. A dentil cornice above runs the full width of the façade; the centre block rises into an attic storey and a steep mansard with dormers.

The treatment of the outer wings is continued along Rosebery Avenue in the angled eastern ranges. Both the cornice and the rusticated basement are carried around this part of the building, and the penultimate bays – with triple-keystone doorways at ground level – have first-floor balconies and architraves, though not pediments, like those on the main front. Above the cornice is an attic storey added in the 1930s and a mansard with dormers. The apex of the triangle is squared off, and here there is a short projecting block forming a secondary frontispiece: this has a semicircular bay window with Doric triglyphs on the ground floor and paired giant brick pilasters flanking a pedimented window on the piano nobile. From the mansard above rises a tall stone tower (another 1930s addition), square below but developing into an octagonal cupola above.

The west range and the short north range are much more simply treated. They are faced in plain brown brick with red brick dressings and a more sparing use of stonework. The southern part of the west range contains the Oak Room, its presence marked by full-height windows retaining their original sashes with ornamental iron balconies and semicircular tympana brought from the old Water House and inscribed 'ERECTED ANNO MDCXIII' and 'RESTORED ANNO MDCCLXXXII'. The north range has projecting wings echoing those of the main front; the eastern wing is surmounted by a bow-windowed penthouse containing the board members' dining room.

Interior

The significance of the interior is greatly enhanced by the Oak Room, which is the primary reason for the Grade II* listing. Much of the rest of the interior is of a lesser order, which would warrant Grade II listing otherwise.

The entrance lobby is a small, approximately square, room lined in rusticated stonework, with a moulded plaster ceiling bearing dentils with guttae and a floor of polished grey and black limestone. Carved roundels bearing the insignia of the MWB's eight constituent companies are displayed in the frieze, with a band of wave-scroll decoration below. The openings at either end are flanked by fluted Roman Doric columns.

Beyond the lobby is the entrance hall, a broad transverse space with a stone floor, pilastered walls and moulded ceiling. At its western end is one of the two principal staircases, its lower flights having elaborate balustrades of wrought-iron scrollwork. A similar arrangement of hall and stairs is found in the north range.

The former Rental Ledger Hall is a rectangular double-height space beneath a glazed elliptical plaster vault with decorated ribs. The original fittings – a curved counter at the entrance and blocks of clerks' desks in the body of the hall – have all been removed, and the side openings infilled, although the glazed hardwood doors at either end remain. Above these are balustraded galleries topped with square lanterns; further balustrades run across the upper-level windows on each side, which are set within lunettes scooped out of the soffit of the vault.

On the first floor of the south range, immediately above the main entrance, is the former boardroom, now the largest and most luxurious of the flats. This has a richly moulded and coffered ceiling supported on giant Ionic columns and pilasters with Bassae capitals. Between these runs a band of wave-scroll ornament, beneath which are roundels identical to those in the entrance lobby. At either end of the room are raised galleries bearing further roundels. The original fittings – a raised dais with semicircular banks of seating – have been removed; two carved hardwood doorcases survive, although the doors have been replaced in glass and a third opening created in place of the dais.

The other parts of the building have been much altered on conversion into flats, although some rooms retain hardwood doorcases, panelling and fireplaces. The basement contains a strongroom of fireproof concrete construction with massive steel doors.

The Oak Room

The richly carved oak panelling and plaster ceiling in this room were installed in the old river house by John Grene in 1693, and were transferred to the new building in 1919-20. The room is square, and originally had windows on three sides, although it is now flanked by lobbies to north and south. The dominant feature is the elaborate chimneypiece, set between Corinthian columns and comprising a white marble fire surround surmounted by an overmantel bearing the full armorial achievement of William III along with trophies depicting a variety of aquatic life – fish, crayfish, crabs, scallops, water plants and so on – as well as pheasants, pigeons, fruits, ears of corn and other more conventional motifs. The upper panels all around the room bear carved wreaths and festoons, some with amorini (winged cherubs' heads), trumpets, drapery and similar motifs. All the carving is done in very high relief in the illusionistic manner of Grinling Gibbons, although the actual identity of the carver is unknown.

The ceiling is no less rich. In the centre is an oval oil painting by Henry Cooke, depicting angels and Virtues bearing aloft an image of William III, enclosed within a wreath of flowers and fruits. The surrounding ornament is divided into three bands separated by ribbon-mouldings. The narrow inner and outer bands contain miniature scenes of hunting, fishing, boating and other riverine and pastoral activities, along with images of fortifications, classical water deities (Nereids, Tritons, Neptune's chariot), rosettes and palm fronds. The broader middle band is of rich acanthus scrollwork, among which appear various species of birds and reptiles. Cartouches at the corners contain swans and dolphins; in the middle of the short sides are roundels with Tritons, while on the long sides are painted shields with the arms of John Grene and Sir Hugh Myddelton. The lobbies on either side, added in 1919-20, also have elaborately moulded ceilings, again with dolphin cartouches. The antechamber to this suite contains two boards emblazoned with the names of the chairmen and vice-chairmen of the MWB from the 1900s to the 1970s.

Two rooms in the south range (not seen) also contain good late-17th-century ceilings from the Water House, originally in the loggias which Grene added to the main block. These have central roundels bearing the date 1693 and the NRC seal, which depicts rain falling from an open hand upon the City of London, along with the motto 'ET PLUI SUPER UNAM CIVITATEM' (Amos 4:7, 'and I shall cause it to rain upon one city').

Subsidiary Features

The main entrance to Hardwick Street is approached via a flight of stone steps whose flanking walls support cross-braced railings and lamp standards. Similar railings, alternating with square stone piers, run along the Rosebery Avenue front, with arched overthrows marking the two side entrances.