Designed by George Checkley, Willow House is a Grade II* listed modernist house built in 1932 for Dr McCombie of Kings College. The house stands in secluded and extensive grounds along Conduit Head Road, which runs through a wooded conservation area to the west of Cambridge City Centre. Conduit Head Road harbours a number of notable Thirties modern houses, including Hugh Hughes’ Salix/Brandon House built for scientist Sir Mark Oliphant in 1934, and Justin Blanco Whites’ Shawms of 1939. In 1933, Willow House (then known as Thurso House) was profiled in both the Architects’ Journal and the Architect & Building News. It is also included in FRS Yorke’s contemporaneous and authoritative text The Modern House in England.

With representatives from English Heritage and Cambridge City Council, we met on site in September with the new owner of Willow House and his project architect, from Nottingham-based firm Letts Wheeler, who conducted a walk-through presentation of their refurbishment proposals.

In 1944 Willow House was divided into two separate residences and a new staircase block and single story sitting room extension were added to the house, both of which project externally from the western end of the building. Designed by Dorothy Cosens, these alterations are justifiably not regarded as being of equivalent architectural quality to the rest of the house; timber rather than metal windows and doors were used, the positioning and proportions of which do not correlate with the design of openings in the main house. As the current proposals will return the house to its original use as a single residence, the Cosens staircase becomes functionally incongruous and will be removed, as will a rather crudely constructed concrete portal from the same period, which is attached to the end of the garden elevation. The single storey extension is to be rebuilt and redesigned in sympathy with the style and detailing of Checkley’s approach, with steel framed windows and doors.
For the earliest owners of Willow House, the plan ensured separation of themselves from ancillary service rooms and housekeeping staff. For residents of the house in less socially stratified times, the same plan becomes restrictive. An opening is to be formed in a ground floor wall, uniting the kitchen and hall spaces. The Society suggested the insertion of a jib door to more subtly achieve this desired intercommunication. The refurbishment programme also includes the formation of a corridor on the ground floor by inserting a new wall, glazed above cill level. A reinstatement of a partition found in the original plan of the house, this partially glazed wall will serve as a screen providing privacy for the study, while articulating movement into the redesigned single storey sitting room at the western end.

The entrance (north) elevation of Willow House, with vertical wooden framed first floor windows, does not sufficiently do justice to the modernist credentials of the rest of the building, and as is often the case the architect has saved his best for the south facing garden elevation (pictured). This façade reflects both the structure of the house (a concrete frame with brick infilling) and the double height nature of the main hall space. The elevation is divided into four bays each with horizontal strips of flush metal-framed windows that span the distances between the vertical members of the concrete frame.

Many of the original steel casement windows corroded and with listed building consent were replaced a few years ago with double-glazed Crittall windows (steel with aluminium cills) that closely match the original profiles. Protected by its position directly underneath the balcony of the main bedroom, the hall’s clerestory window is the best-preserved original window, and it will be retained in situ as evidence of original detailing. It is also hoped that original ventilation air bricks (visible in the garden façade) will be similarly preserved and perhaps restored to working order.

With no form of vestibule other than a small porch, immediately upon entering Willow House one is placed at the heart of the interior plan: a split-level hall/dining area. Reinforced concrete winder stairs with a low solid balustrade curl up to the first floor, from where the main hall can be monitored from a gallery. This split-level hall/dining area is reminiscent of multifunctional domestic spaces designed by English Arts and Crafts architects such as Voysey and Baillie Scott, whose reinterpretations of the traditional medieval hall and gallery arrangement were a source of inspiration for the likes of Adolf Loos, as well as perhaps Checkley.

The original jointless ‘Magnesite’ floor covering in the hall has been discoloured and damaged beyond repair by damp and is to be replaced with oak boarding to match the upper floors in the house (magnesite on the stairs can be retained and restored). Replaced by a wood-burning stove, the original hall fireplace will be reconstructed to match the original design as closely as possible. A number of flush gas panel heaters in the house are to be retained, now disconnected but part of a system considered experimental when the house was built.

Like many modernist villas of this period, cold bridging, condensation and water penetration are problems that have inevitably derived from the relatively new construction techniques and materials employed by Checkley, compounded by inadequate maintenance to aspects such as the render, windows, flat roof and copings. The build currently has no insulation to the external walls, which are without cavity. After much debate, and contrary to the recommendations of the Society, it has been decided that an insulating rendered panel system is to be fixed to the exterior of the house. To ensure that window reveals continue to be flush with the facades, all windows will be moved forward to compensate for the thickness of the insulating panel (about 3.5cm). This approach represents a significant cost saving, but the ideal solution would have been to strip all existing render and re-apply afresh. The colour of the exterior will be a creamy-buff tone, as was the original self-coloured ‘Snowcrete’ waterproof render.

Although some of the Society’s concerns have not been fully allayed, the refurbishment of Willow House will certainly result in the building returning to a state more closely resembling original. The project illustrates the give-and-take nature of trying to sensitively balance the needs and expectations of modern life against the need to preserve our design heritage.

Laurence Rich