For George Checkley's 1932 Willow House, Letts Wheeler Architects has sought a balance between restoration and adapting a home to today's standards
George Checkley (1893-1960) was primarily an architectural academic, with a small built oeuvre. Born in New Zealand, he studied at Liverpool and won a year studentship in Rome, bringing him into closer touch with continental Modernism than many a UK architect. His two key buildings are very early essays in white Modernism for the UK, located within the Conduit Head Road Conservation Area in Cambridge - The White House (1931), for himself, and Willow House (formerly Thurso House) for fellow Cambridge academic Hamilton McCombie.
The front (north) of Willow House is a bit short on Modernist conviction, with strip windows to the ground floor but sash-proportion vertical punched openings above. The south elevation, facing the large garden, is much more convincing, with strip windows at both levels that wrap onto the east and west flanks to further-reveal the concrete framing.
This south face is enlivened by a projecting balcony and a single second-floor bedroom, off-centre. These reflect the interior, organised around an internally balconied double-height living space, with the externally balconied bedroom projecting above. Overall, the house has a simple arrangement of living spaces downstairs and sleeping accommodation above. Its entrance is unceremonial, a simple porch before the main living space, at first low under the internal balcony, then opening to full height. True to its time, kitchen/laundry spaces were a servants' realm rather cut off from the rest of the plan.
Willow House was listed Grade II* in 1992, and now, after 70 years of life, needed some upgrading. Its poor condition was the product of the experimental nature of the original construction - it cost some £2,550, several times the price of a traditional house; of a subsequent lack of response to these built-in weaknesses; of limited maintenance; and of periodic changes by owners and tenants.
The main organisational changes over the years have been the building of a small lounge extension and stair tower to the west side in 1944 to allow the house to be let as two residences; and in the kitchen, removal of a structural wall and blocking in the south-east corner porch. These were accompanied by many minor changes to fabric and services, none of which has done much for the long-term amenity of this building as a home. So the conservation issues are mostly simplified to how far to restore the house as it was in 1932; how much to adapt it to today's needs for its new owners. Reading between the gentlemanly lines, the architect was readier to lose traces of the past than the conservation voices; the resolution is one of significant but sympathetic change.
In the mid-1990s another house was built on the garden immediately (1.5m at its closest) to the east. No boundary wall/fence has been erected between, so some of the original flow of the garden remains in this direction.
Prior to Letts Wheeler's involvement, architect John Winter had been working on Willow House over several years in ad hoc mending, 'without contract or budget', responding to calls for help but never free to get to grips fully with the problems. The structure is a concrete frame, infilled with 9inch masonry walls, its intended concrete floors and roof in fact built from timber joists. Shortly before Winter's involvement, in 1995, the roof terraces - originally felted and overlaid with half an inch of macadam - had been re-covered with a single-ply membrane. Leakage continued at upstands and copings. Tenants were told not to walk on it.
Winter did some work on these alongside many other 'little jobs' over the period. Most significantly, in 1999 Winter worked with repair specialist Makers to repair widespread cracking, mainly at the masonry-concrete frame junctions and due to reinforcement expansion, with reinforcement exposed in some places. At the same time about half the steel-framed windows (mainly on the south) were replaced with galvanised, powder-coated windows of modern specification - Crittall Homelight, double-glazed and weatherstripped. Steel doors were also reinstated, and the original black-painted lead sills, whose replacements had now also failed, were replaced too, this time in white powdercoated aluminium. An example of the original windows and window ironmongery (with its winding mechanism) has been retained at the upper level in the living space, where the windows are shallow and protected from the weather by the balcony above.
The porch inner door was also refurbished.
All these changes were not without controversy. But Winter describes the conservation officer he dealt with as 'the best I've ever met'.
For Letts Wheeler, new owners provided the occasion to take a broader view while returning the house to a single-owner occupancy. Organisationally, the architect has removed the second stair, of 1944, and reshaped the lounge extension to be more in keeping with the original house's fenestration.
It removed storeroom walls to open up space within the kitchen and made a large opening through to the living space where there had only been a hatch. This was for clients who see the kitchen as very much part of the social, as well as functional, heart of the building. It also reopened the kitchen to the garden by glazing what had originally been a porch, using translucent glazing where it faces the house immediately to the east. The smallest bedroom, little more than a box room, has been converted into a second bathroom.The garage has been converted to a gym with a new entrance door and new glazing to the west; a new, larger detached garage has been built.
Externally, there is a new pool and terrace within an existing beech hedge to the west, and new paving and gate to the front.
The biggest change, now largely unobtrusive, has been to overclad the house in insulated render, and in the process complete the renewal of steel doors and windows and aluminium sills. This overcladding simultaneously protects the fame and masonry from the weather and raises the poor thermal standards of the envelope, integrating too with the installation of new damp proof course and damp proof membrane.While the walls had a damp proof course, failed in parts, this was set below the top of the floor slab, which had no damp proof membrane. One past response to the ensuing damp penetration had been to cut back the render, which originally ran down to the ground, to above the damp proof course, and paint the plinth black. Letts Wheeler and Sto developed a detail to allow the new render to meet the ground again, alongside new damp proof course and damp proof membrane. Though the insulation board is only 30mm thick, overcladding did require relocation of all windows to lie flush with the surface render. The same body-coloured light cream render was also used for the inner faces of the parapet walls and the curved garden wall at the front.
Of the myriad smaller changes, several stand out. There are new aluminium copings to the parapet - originally concrete, subsequently capped in felt - and new paving to the roof terrace over the recent single-ply membrane. The entrance porch roof is now leaded and slopes away from the wall, rather than towards it - it never had a gutter and downpipe.
Internally, the 'Magnesite' jointless ground-floor topping had failed without a damp proof membrane, but the clients were persuaded by the conservation officers, at some expense, to repair this material at least on the stair and balcony. The ground floor is now oak, with skirtings matching those on the first floor, in plain 5 x 75mm painted hardwood. One cylindrical light fitting was visible in an early photograph of the living space; the architect found a very similar fitting and reinstated it there, also using it for the corridor and porch. As part of replacing doors and windows, ironmongery has largely been (sympathetically) replaced; otherwise this home would not have been insurable.
Radiators (containing asbestos) were originally set flush in shallow recesses in the wall surfaces and have been replaced with new, though somewhat deeper, radiators. Originally this oil-fired heating system was backed up by gas-fired panel heaters in most rooms.
Long ago they ceased functioning but two have been retained, in the dining area and topmost bedroom. Electrics have been replaced.
In bedrooms there are grilles in the ceiling, that connect via the floor voids to grilles in the outer walls. This was perhaps an early, doomed attempt at passive stack ventilation.
The national stock of houses such as Willow House is small, but not small enough to contemplate fossilising them as museum pieces. The urge to preserve is understandable but not practicable. They have to be living buildings. There will always be arguments about where boundaries lie - should the marble-topped contemporary kitchen fit-out have been compromised by English Heritage's wish to keep the original butler sink? In this case, it went. Overall, Willow House has crossed the thorny landscape of conservation debates and come out well, with a new lease of life.
CONSTRUCTION FROM AJ 19.4.1933
Frame - reinforced concrete work is chiefly confined to the external walls, formed in concrete frames with 9-inch brick infilling, finished externally with cream cement render.
Reinforced concrete is also used for the staircase and gallery in the hall, external balcony, shelter on the roof and internal lintels and ties.
Partition walls - brick or breeze blocks.
First floor and roofs - wood joisted construction on account of cost.
Roofs - finished with standard flat roofing (bituminous felt) and macadam.
Flooring (ground floor) - whole of ground floor with exception of boilers, larder, maid's WC, tradesmen's vestibule, store and garage finished in jointless flooring on concrete sub-floor.Boilers, larder, etc, in granolithic concrete.
Flooring (first floor) - bedroom one in jarrah; other rooms in Japanese oak.Stairs and steps from gallery level in American oak.
Hall fireplace - reconstituted marble.
Heating and hot water, etc - boiler with indirect cylinder for domestic supply; it runs 11 flush heating panels placed beneath windows.
Fuel - oil, burnt in automatic oil burner, under aquastatic control; also fitted with timer.Oil supply from lorry is pumped to fuel storage tank through stand-pipe in hedge on roadside.No coal or coke used - wood fire in hall.
Secondary heating - gas fires in all bedrooms and in study, dining recess and kitchen.
TENDER DATE September 2002 START ON SITE DATE November 2002 CONTRACT DURATION Five months CONTRACT JCT Minor Building Works 1998 TOTAL CONTRACT VALUE £278,693 ARCHITECT Letts Wheeler Architects: Andrew Wheeler, Matthew Letts, Richard Keighly, Andrew Shaw STRUCTURAL ENGINEER Price & Myers MAIN CONTRACTOR TJ Construction (Cambridge) SUBCONTRACTORS AND SUPPLIERS Asbestos removal Haylock and Rolph; single membrane roofing Fenland Flat Roofing; damp proofing Anglia Property Preservation; electrical distribution Ian Grinling Electrical; heating and plumbing installation TJ Construction; stair restoration Fairhaven of Anglesey Abbey; decorations KTF Decorators; Crittal metal windows Anglia Fixing (Stratford); steelwork Balsham Building; metalwork, gate, fireplace Crofton Engineering; leadwork H Austwick (Lead and Copper Roofing); slate fireplace and surround Hibbit and Sons; ironmongery supplyMillar Partners;
coping Alumasc; mastic West Anglian Insulation; sanitaryware supply Willbonds; Sto render Retrofit UK; garage door, motor Cambridge Garage Doors; joinery Coach House Joinery; Kars floating floor The Traditional Flooring Company; tiling TJ Construction; marble worktops J Rotherham Masonry; tree removal SP Landscapes & Tree Contractors
Letts Wheeler Architects www. lettswheeler. com Price & Myers www. pricemyers. com