INTRODUCTION

The Wood Shed is the only survivor of a former complex of agricultural buildings in the South East of North Mymms Park, a Grade I listed mansion at the centre of a 700 acre park and farm land estate. The building sits at the north-west of a plot of just under a hectare, next to a long exposed wall of one of the enclosed gardens of the main estate. An ‘L’ shaped building, the existing structure is made up of an enclosed room with a stove for the woodworker’s use, three open bays, a store and the shed for cutting timber.

The existing screen of the Wood Shed is the defining architectural element of the building, and the most striking when visiting the site: an open grid of timber strips form an enclosure that allowed air to circulate through the structure encouraging timber to dry. The simplicity and clarity of purpose of the Wood Shed has something of the qualities of the ‘Primitive Hut’, used by Vitruvius, Laugier and others as an allegorical explanation of the origin of architecture. The Wood Shed shares some of the expedience of fashioning existing trees, in their unaltered form with bark and branches, into columns and beams. This in turn has informed some of the proposed architectural details. The aim was to preserve the essential qualities of the existing building, and through a series of careful responses, to bring it back to life. This has been approached formally; through an overlaying of grids at different scales; volumetrically, by preserving the existing spaces and making any architectural addition or expansion of programme legible as a separate object; and finally through the use of materials.

Using a palette appropriate to the working and functional nature of the existing building (such as plain and glazed brick; clay tiles and Georgian wired glass, a practical but beautiful material that adds another layer of complexity to the narrative of the grid and the role it plays in the building) it becomes possible to create a sensual and subtle response to an essentially very simple building.

The simplicity, honesty and clarity of purpose of the Wood Shed has something of the qualities of the ‘Primitive Hut’, used by Vitruvius, Laugier and others as an allegorical explanation of the origin of architecture. The Wood Shed shares some of the expedience of fashioning existing trees, in their unaltered form with bark and branches, into columns and beams. This in turn informed some of the architectural details, such as the waney edge of the horizontal bars of the consented screen system.

CONTEXT

“A mansion, built c.1600, for Sir Ralph Coningsby in late Elizabethan style. It was originally a courtyard house but appears now in H-plan. One of the best Tudor houses in the county. The interior has been remodelled and altered at various times, particularly in the late 19th century, when the Burns family carried out extensive alterations and added a large wing to the west side. Apart from a central loggia, this was removed in 1947. The large stable block also dates to the 1890s. In 1987, an important series of late 16th or early 17th century wall paintings depicting the Nine Worthies, and figures probably of ‘Fortune’ and ‘Fame’, were discovered during extensive repair work following a major floor collapse resulting from a long period of neglect, water leakage, and consequent dry rot in the house. Wall paintings of probable 17th century date have since been found in a first-floor bedroom, high on the south and west walls and representing a carved marble frieze. This is punctuated by strapwork cartouches enclosing coats of arms, which may be much later. Paintings of a frieze of grotesques, probably contemporary with the Nine Worthies, are ‘beneath the panelling in the Marble Hall’. 

In the 19th century the house had two major phases of alteration and additions, the first by Edward Blore for Fulke Greville in 1846-47. Greville’s arms are used in surviving decorative details. Blore’s new entrance hall was replaced following the sale of the house to wealthy Americans, Walter and Mary Burns, who employed Sir Ernest George and his then partner Alfred Yeates to transform the house and grounds in the period 1893-1910. From 1940 to 1946 the house was used as part of a military hospital in the grounds. The Burns family sold the major part of the estate in 1979 and by 1985 it was in corporate ownership. The 1890s stable block was converted to residential use, and in 1992 the house was bought by GlaxoSmithKline as a training centre.” The house has recently changed hands again.

DESIGN

An important part of the formal approach to the transformation was to literally outline the original building footprint to distinguish it from the new additions. This was done with a herringbone path that now ‘frames’ the existing, historic structure, as the sacrosanct core of the entire scheme. The act of separating out the new interventions from the old has the effect of creating a formally coherent and legible architecture.

The path acts as a ‘ribbon’ that joins the two building wings and connects all inhabitable spaces from the most public (the main entrance, main living space and kitchen) to the most private (the study, master bedroom and bathroom). It becomes a serial unfolding of the architectural events of the building. Following this path reveals every aspect of the architecture and the narrative thinking behind it. This is a building articulated through its tactile detail that the close proximity of the path delivers.

The dimensions of the path vary as it wraps around the building. At the south elevation, the path is the same width as the existing concrete paving where it becomes a terrace; a place to linger outside. Where it runs under the roof that connects the new (consented) bedroom to the existing building, it forms the main entrance threshold. At the west elevation, the path is discreet and functional. At the east elevation, the path becomes an external shower surface, before concluding its journey in the master bathroom.

At the north elevation, the path steps down making it accessible and passable under the existing eaves while staying close to the building. It means that the consented low wall is bench height at its two extremities, and counter height at its centre. This allows the near invisible insertion of a compact kitchen between the main building and the consented rear wall, providing a rich spatial complexity. 

The dark grey brick acts as a plinth to the kitchen wall, separating the addition from the existing building, and the wall coping detail will run through the building to become the kitchen counter internally.

The herringbone ‘ribbon’ flows around the existing structure and even through the building where it separates the old from the new – at the covered entrance and the kitchen addition – creating magical and surprising encounters of different scales, textures and light qualities. Where the path is internal, the slate infill is cement rather than sand, with the surface ground to a honed finish to create a ‘slate terrazzo’. Along its entire length, the slate remains legible as a continuous material.

The herringbone path plays a very important aesthetic and conceptual role in the repurposing of the Woodshed. It was constructed by the Flintman Company, an excellent team of artisanal craftsmen – specialists in flint, lime and masonry construction – with whom Skene Catling de la Peña closely collaborated on the Flint House at Waddesdon Manor, Buckinghamshire.

SLATE HERRINGBONE

An important part of the formal approach to the transformation was to literally outline the original building footprint to distinguish it from the new additions. This was done with a herringbone path that now ‘frames’ the existing, historic structure, as the sacrosanct core of the entire scheme. The act of separating out the new interventions from the old has the effect of creating a formally coherent and legible architecture.

The path acts as a ‘ribbon’ that joins the two building wings and connects all inhabitable spaces from the most public (the main entrance, main living space and kitchen) to the most private (the study, master bedroom and bathroom). It becomes a serial unfolding of the architectural events of the building. Following this path reveals every aspect of the architecture and the narrative thinking behind it. This is a building articulated through its tactile detail that the close proximity of the path delivers.

The dimensions of the path vary as it wraps around the building. At the south elevation, the path is the same width as the existing concrete paving where it becomes a terrace; a place to linger outside. Where it runs under the roof that connects the new (consented) bedroom to the existing building, it forms the main entrance threshold. At the west elevation, the path is discreet and functional. At the east elevation, the path becomes an external shower surface, before concluding its journey in the master bathroom.

At the north elevation, the path steps down making it accessible and passable under the existing eaves while staying close to the building. It means that the consented low wall is bench height at its two extremities, and counter height at its centre. This allows the near invisible insertion of a compact kitchen between the main building and the consented rear wall, providing a rich spatial complexity. 

The dark grey brick acts as a plinth to the kitchen wall, separating the addition from the existing building, and the wall coping detail will run through the building to become the kitchen counter internally.

THE FLINTMAN COMPANY

The herringbone ‘ribbon’ flows around the existing structure and even through the building where it separates the old from the new – at the covered entrance and the kitchen addition – creating magical and surprising encounters of different scales, textures and light qualities. Where the path is internal, the slate infill is cement rather than sand, with the surface ground to a honed finish to create a ‘slate terrazzo’. Along its entire length, the slate remains legible as a continuous material.

The herringbone path plays a very important aesthetic and conceptual role in the repurposing of the Woodshed. It was constructed by the Flintman Company, an excellent team of craftsmen – specialists in flint, lime and masonry construction – with whom Skene Catling de la Peña closely collaborated on the Flint House at Waddesdon Manor, Buckinghamshire.

BRICK

The original Woodshed was constructed of simple, readily available materials, namely brick and timber. In the conversion from an agricultural building into a house, it was an architectural goal to distinguish the old from the new while highlighting areas of different use and differentiating between shared and private space using different types of the same basic building unit: the brick.

To that end, the building consists of a combination of different brick treatments. Where walls are unchanged, the original bricks remain in situ. The bricks of walls that were taken down have been reused. The north rear wall facing the road has been conceptually ‘displaced’; effectively the back wall of the original building has been shifted out by 1.5 metres to create the new, long kitchen. To highlight its status, the old red bricks sit on a base of new dark grey ones that read as a plinth. Dark grey bricks have also been used to construct the bedroom extension to the south in order to make the old and new legible and distinct.

The roof to the new extension creates a covered entranceway, the formal access into the building. With the same logic, the additional section of the roof here is covered with black clay roof tiles, pierced with small openings of overlapping glass tiles to allow light through.

The walls of the covered entranceway, which most people will pass through and linger in, continue the language of red brick for the existing building and black for the new, but here their faces have been dipped in a clear glaze and refired to create a vitreous, gently gleaming surface that is smooth to touch. The refiring has enriched the red which has become darker and more saturated, and made the dark grey turn a deep, warm brown. In each case, a coloured lime mortar was mixed to match the bricks. Where the glazed bricks turn the corner, there is also a transition from one mortar colour to another: from deep red to a natural lime mortar, and from warm brown to a dark grey. To mark these transitions and reinforce the corners at the covered building entrance, thin red tiles were inserted into the ‘red’ corner, and squares of dark grey roofing slate into the ‘black’ corners.

HG MATTHEWS

The clay bricks were made locally by H G Matthews. They use a clay found only in the Chiltern Hills, which has been used for centuries because of the beautiful colours it lends to the finished brick. It is hard to find and extract as it is only appears in small, isolated pockets thus making very large scale brickmaking impossible in the area. Colours depend on the clay and the temperature the brick reaches during firing, which varies according to the location of the brick within the kiln. The bricks set at the edge of the kiln where temperatures reach around 900°C will be orange. At the centre the temperature reaches up to 1200°C and results in a brown brick. The middle ranging colours come between these two limits. They keep hand making skills alive as well as firing in traditional updraft Scotch kilns, fundamentally unchanged in design since Roman times.

In addition to the clear glazes and refiring of the red and grey bricks used externally in the covered entrance, H. G. Matthews developed a bespoke glaze for one of the guest bathrooms. They used iron filings scattered into a neutral glaze over the surface of the grey bricks, to create a mysterious dark, green-black colour with a metallic sheen.

CAST GLASS BLOCKS

Into the glazed walls of clay bricks, hand polished, Venetian cast-glass blocks of the same dimensions were inset using the same Flemish brick bond as the rest of the wall. The glass blocks sit on slivers of Perspex which increase the depth of the joints to match their clay neighbours. They are bonded with a UV activated glue and are sealed with clear silicon. The glass bricks were cast in Venice by a company called Poesia. After casting, they were hand polished for crystalline clarity. They were installed by the Poesia team after the clay brick walls were completed, having been constructed around templates of the glass block ‘windows’ in order to leave the correct sized opening.

The glass bricks create a number of different effects depending on the time of day, the source of light, and the angle at which they’re viewed. When they’re seen from oblique angles, they seem to disappear into the surface of the walls, only to reappear when viewed front on. It is as if the clay brick walls magically dissolve and become transparent.

TIMBER SCREENS

The main architectural challenge was to preserve the appearance of the open screen, while making the building weatherproof and inhabitable as a domestic space. This led to a focus on the grid at several different scales to act as a flexible organizing element, a screen to filter light while also able to allow through a breeze; a framing device, and access in and out of the building. 

The waney edge is kept on the external horizontal timber sections, to reinforce the brute simplicity of this pragmatic screen, the building’s origins as a place to work raw timber, and the Primitive Hut. In contrast, the internal surface of the screen has a cut and worked finish. While screws were used in the prototype, stainless steel pins and timber pegs are used for the actual screen. 

The building aims to crystallise and articulate the historic value of the Wood Shed within the context of a larger working estate, in an authentic architectural language that respects the original while avoiding historicism or pastiche.

It was decided early on to recreate an external open timber screen with the same dimensions as the existing. Behind this is the larger, lightweight grid of a steel-framed, Crittal system of glazed panels and openings, each pane a multiple of the modules of the outer screen and so completely concealed by it. 

Finally, there is a third, delicate, miniature grid within the panes of Georgian wired glass, like hairlines or graphite pencil marks. Georgian wired glass is a functional material, the purpose of its embedded grid to add inherent safety and strength. Its unpretentious nature resonates with the pragmatism in the approach to the construction of the original working building. But this glass is also very beautiful. Here it makes up an outer perimeter of translucency that frames an inner square of clear glass, focusing views and creating privacy while still allowing through diffused light and colour. The inner square can either be a window, or the central panel of a pair of doors. Diagonals serve both as cross bracing and door or window handles, preserving the distinct ‘X’ silhouette of the original timber structure.

DIAMON CRYSTAL QUARTZITE

The counter between the kitchen and the main space is designed to mediate between the formal dining and informal working space. At the centre of the deep plan of the house, a pale colour was chosen to reflect light further into the space. Originally a white onyx was chosen to respond to the ‘clouds’ of alabaster that line the rear wall of the kitchen, but this was replaced with an extraordinary piece of diamond crystal quartzite. Quartzite is a much more resilient material than onyx, but the clarity and unique markings of this particular slab create a glamorous counterpoint to the more sober and pragmatic slate surface that runs along the back wall and continues as a datum line that links the inside and outside spaces.

Quartzite is a non-foliated metamorphic rock composed almost entirely of quartz. It forms when a quartz-rich sandstone is altered by the heat, pressure, and chemical activity of metamorphism. Metamorphism recrystallizes the sand grains and the silica cement that binds them together. The result is a network of interlocking quartz grains of incredible strength. Its extreme toughness made it a favourite rock for use as an impact tool by early people. Its conchoidal fracture allowed it to be shaped into large cutting tools such as axe-heads and scrapers. Its coarse texture made it less suitable for producing tools with fine edges such as knife blades and projectile points. Obsidian, flint and agate were better suited for tools where sharpness was important.

ALABASTER

Just as timber in its raw state, complete with its bark, was used to evoke the qualities of Laugier’s Primitive Hut, and Vitruvius’ Origin Myth, so too alabaster was chosen as a stone that could reveal its natural state. Alabaster is used both in the main space, as a sculptural chimney piece, and in the kitchen to line and protect the rear wall.

The purest alabaster is a snow-white material of fine uniform grain, but an oxide of iron produces brown clouding and veining in the stone, which was desirable for the Wood Shed. The chimney piece was conceived of as something almost primordial, a deep, three-dimensional sculpture formed by carving up and then reassembling an excavated sphere of the stone. The cladding to the rear of the kitchen is conceived as a linear strip of ‘slices’ of alabaster, assembled together to read as clouds rising from the dark slate counter, the light from above catching the raw, natural ‘rind’ of the stone. The larger pieces coincide with the sink and the cooking area, where the wall needs most protection. They reduce to a narrow band in other areas.

The alabaster in the Wood Shed was sourced in Spain. Much of the world’s alabaster is extracted in the Ebro Valley in Aragon which has the largest known exploitable deposits. After the design intentions for the Woodshed were complete, the architects worked closely with Adam Lowe and Francesco Cigognetti to adapt them to specific pieces of stone. This raw material was then turned into the finished objects in the Factum Arte workshops in Madrid. Factum Arte have made extraordinary artworks from alabaster, exploiting its qualities of delicate translucency, for world renowned artists such as Marina Abramovic and Rachid Koraïchi.

Archaeologists and the stone processing industry use the word ‘alabaster’ differently from geologists. The former use it in a wider sense that includes varieties of two different minerals: the fine-grained massive type of gypsum and the fine-grained banded type of calcite. Geologists define alabaster only as the gypsum type. Chemically, gypsum is a hydrous sulfate of calcium, while calcite is a carbonate of calcium. The two types of alabaster have similar properties: they are usually lightly coloured, translucent, and soft stones and were used throughout history primarily for decorative carving, but also in thin sheets as windows.

Gypsum alabaster is a common mineral which occurs in England in the Keuper marls of the Midlands, especially at Chellaston in Derbyshire, at Fauld in Staffordshire, and near Newark in Nottinghamshire. Deposits at all these localities have been worked extensively. In the 14th and 15th centuries its carving into small statues and sets of relief panels for altarpieces was a valuable local industry in Nottingham, as well as a major English export. It was also used for the effigies, often life size, on tomb monuments, as the recumbent position suited the material’s lack of strength. Alabaster is also found in smaller quantity in Somerset. In Cumbria it occurs largely in the New Red rocks, but at a lower geological horizon. The alabaster of Nottinghamshire is found in thick nodular beds or ‘floors’ in spheroidal masses known as ‘balls’ or ‘bowls’ and in smaller lenticular masses termed ‘cakes’. 

SPLASHBACK

FIREPLACE

CIPOLLINO

Cipollino marble (literally, ‘onion-stone’) is a metamorphic rock, a crystalline marble with coloured veins of epidote and chlorite. It has a white-green base, with wavy green ribs held by strata of mica. It is a wonderfully evocative stone with a great deal of watery movement. The intention for the Wood Shed was to keep the palette plain, avoiding decoration and colour, to leave space for moments of extravagant richness introduced through natural materials, the marble, alabaster, timber and slate.

First used in ancient Greece and exported to Rome from the 1st century BC; in his Natural History, Pliny the Elder describes columns of this marble in the home of Claudius Mamurra, an engineer for Julius Caesar in his Gallic Wars. The quarries producing it became imperial property, and cipollino became common throughout imperial Rome. It was principally used for large and mainly smooth column shafts. It was also used for sculpture, such as the crocodile in the Canopus at the Villa Adriana at Tivoli, where its colour was used to imitate crocodile skin.

Cippolino was used in the master bathroom of the Wood Shed to create a long counter the width of the room, containing a basin carved into the stone with minimal detail. This is set against a floor of honed slate terrazzo. Here, large doors can open the room entirely to the outside. The wall opposite the glazed doors is clad in panels of two-way mirror. Two-way mirror is more subtle than ordinary mirror glass as it allows light to pass through it. Behind the mirrors, subtle lighting changes how they behave; when the light is low, they reflect the landscape outside. When the light is turned up, they release rather than reflect it. An internal Perspex screen means that the internal light reads almost as a mist. The mirror becomes active, like an abstract sculpture.


PROJECT TEAM