In-between Space | Indoor-Outdoor Timber Architecture + Visual Gardens

A Philosophy of Symbiosis

Cover. Shippocho House [House in Shippocho], Nagoya, Japan [2011]. Architecture: Toshihito Yokouchi Architect & Associate. Photographer: Isao Aihara.

Introduction

'Western societies have two dimensional cultures [interior and exterior], while Japanese society has a three - or multi-dimensional culture [interior, intermediate, and exterior].'1

- Kisho Kurokawa

Definition
The 'engawa' is a modern interpretation of one of the most pronounced and distinguishing qualities of traditional Japanese architecture and way of life – the ‘edge’ and 'connection' at the side of a house or Zen Buddhist temple which functions as a verandah for viewing the garden.2

Philosophy
To establish both a physical and visual, gentle flow of life between public and private spaces, is not only a question of new floor-to-lintel door-window openings and ‘French doors’; but also a question of how the indoor-outdoor connections between the two areas is designed and detailed. Sharply demarcated borders or abrupt changes - where one is either in a completely private territory indoors or in a completely public area outside – will make outdoor stays [the key word is staying] more or less impossible, because edge conditions are very poor.

This is the edge effect: a phenomenon in which the preferred places for staying are found along the borders of the spaces or at the edges of spaces within the space.3 The theory for the popularity of the edge is that the edge provides the best opportunities for prospect and refuge.4 That is, people prefer indoor and outdoor spaces suitable for both: visually surveying and contemplating the surrounding environment for both opportunity and hazard; and a sense of retreat and withdrawal – for protection, work, rest or healing.5

House-Garden Relationship
The design goal of prospect-refuge can be summarised as the insertion of what Kisho Kurokawa calls an ‘intermediary zone’6 i.e., engawa: into the semiprivate front yard with a view of the street; and beside the door-window looking out onto outside space. Architecturally, it is multi-dimensional, serving simultaneously as a shelter against rain, wind, and summer heat; an outdoor verandah to stop, sit, and view the garden; and a connecting space where inside and out merge as one.7 Perhaps the most important role of the engawa is as an open-air vestibule where simple social transactions can be conducted or extended conversations can take place, while drinking tea and eating snacks8 - in a relaxed and undemanding way.9

Structure
The engawa incorporates three classical motifs of traditional Japanese architecture which have been perfected over 2000 years of trial and error.10 These motifs are indicated as being: a broad 3½ ft. deep [1,060 mm.] edging strip of raised floor planks; 'ishibatate' or 'standing on the stones'11 post-and-lintel skeleton frame construction;12 and a large pitched ‘hidden roof’ ['noyane'] composed of an externally visible first roof and a second roof visible only from under the projecting eaves.13 The predominant building material is wood: Mainly softwoods such as Douglas Fir and British Larch, but also resistant hardwoods, such as European Oak - selected for grain and natural beauty, polished, and seldom [if ever] marred by paint. In addition, most structural materials will be ‘exposed’ and will not be hidden;14 to show the art and craftsmanship of traditional Japanese carpentry and joinery.

Construction
Described as ‘rapid accelerated timber frame construction’, the process starts at a workshop, where the architectural drawings are turned into shop drawings that the computers can read by a team of highly skilled carpenters.15 From here, the major components forming both the framework and roof, are milled, hand-finished, and pre-fit in advance, for ease of assembly and disassembly in the construction process.16 As a result, the actual building process consists of merely assembling the various components, and takes but a few days: the groundsill is provided with a foundation of natural stone post bases; the posts are erected upon the bases in standard distances and connected to each other by a horizontal lintel, thus completing the upright framework. Upon the lintel, rafters and purlins are laid; the roof is covered and loaded with tiles.

Once material and man is protected against the frequent rains, the carpenter can continue his work with more ease and leisure. Floor planks are laid upon a sleeper-joint construction, with great care being exercised in giving an exquisitely soft sheen to the surface; and finally, the engawa’s most vital ingredient, the movable chair, is laid.17

Note 1

Click on any image to open the lightbox gallery: a feature that allows you to view and enlarge images in full-screen mode, as well as switch between them horizontally.

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Matte Painting

Conceptual Diagramme

Fig.1. Dead Space

Fig.2. Intervention

Fig.3. Prospect

Fig.4. Refuge

Note 2. Dead Space

Semiprivate and private residential outdoor space in which one sees concrete covering land which once supported hundreds of varieties of plant and animal life; a hedge or a tangle of bushes; one or two private cars, and the preternaturally ugly ‘wheelie bin’; but few people, if any, because conditions for outdoor stays [the key word is staying] is more or less impossible. Under these conditions most residents prefer to remain inside, what are most certainly sensory-reduction environments, in front of the television – the greatest mind control tool ever created.

Note 3. Intervention

Floor, wall, and ceiling planes serve to define and isolate a portion of space. Of these, the wall plane, being perpendicular to our normal line of sight, has the greatest effect as a spatial boundary. It limits our visual field and serves as a barrier to our movement. Intervention is a procedure often distinguished by a small, non-structural cut or subtraction of a parapet – the wall plane below a window facing a semiprivate front yard or a private backyard. Without a parapet to block, a window gives way to a porte-fenestre [Fig.5], merging inside and outside, home and garden - both visually and spatially.

Note 4. Prospect

People prefer environments and spaces that provide unobstructed views or vistas from multiple vantage points, so that internal and external areas can be easily surveyed and contemplated for both opportunity and hazard. In natural environments, prospects include open terrain, copses of shade trees, an understory of herbaceous flowering plants, bodies of water, and evidence of human activity or habitation. In human-created environments, prospects include open or semi-open floor plans, deep, elevated terraces and balconies, the generous use of windows and glass doors, louvred or slatted filters and screens, and thickly planted shrubberies less than or equal to 1m [42in].

Note 5. Refuge

People prefer the edges, rather than middles of spaces; spaces with ceilings or sheltering canopies overhead to provide protection from weather; spaces with few access points [i.e., protected at the back or side]; and spaces that provide a sense of safety and shelter, retreat and withdrawal – for work, protection, rest, contemplation or healing. In natural environments, refuges include enclosed spaces such as caves, dense vegetation, and climbable trees with dense canopies nearby. In man-made environments, refuges include roofed, open-air architecture, lowered colours, temperatures or brightness, and translucent [or semi-opaque] shades, blinds, screens or partitions.

Fig.5. Porte-fenstre

Note 6. Porte-fentre
A wood, weather-stripped frame and a single side hung – outward or inward - sash around a two-pane insulated glazing unit, serving as a window and a door. The conventional use of two window sashes – one active, and one non-active leaf - is deliberately avoided in order to maximise the amount of natural light passing through the opening as well as minimise the visual impact of window bars and sashes, as the sitter gazes towards the brightness of the garden. Perhaps, more importantly, it becomes part of a living concept that allows for an easy progression from indoors to outdoors, with decks, terraces and gardens seen as natural extensions of personal living and dining space.

Isometric Impressions

Fig.1. Mid-terrace @ semiprivate front yard with engawa verandah and tsubo-niwa 1.50

Fig.2. Front facade beside engawa verandah and tsubo-niwa 1.24

Note 7. Engawa verandah
Modelled on the refined shoin-zukuri timber-floored open corridor or verandah constructed around the outside of a traditional Japanese Zen Buddhist temple or house, and crafted primarily from solid wood, the engawa or en [‘edge’ and ‘connection’] space comprises of an elevated viewing deck of slatted floor planks [across its width]; a post-and-lintel skeleton frame raised upon a series of tapered granite bases [along its length]; and a ‘hidden roof’ consisting of an externally visible and exposed large slanting roof plane with overhanging eaves; and an intricate and elaborate framework visible only from under the eaves [along its length].

Note 8. Tsubo-niwa
A key feature of some traditional Japanese machiya [townhouses], shops and temples - adapted to the context of the traditional semiprivate front yard with a view of the street - the tsubo-niwa is a small to very small courtyard garden characterised by two simple yet beautiful elements: a ‘living screen’ that is designed to be enjoyed while seated on the outdoor deck or in the main living area of the house, while adding some privacy and intimacy for the sitter; and a path of white gravel or sand, to establish what is generally referred to as a threshold - an acoustic zone of passage or pause between the very public residential street and the semiprivate engawa or verandah.

Note 9. Living screen
An expanse of closely spaced shrubs, grasses, sometimes ornamental trees, and curved water bowls, planted and trained along the periphery or edge of a deck or terrace. Its special character is primarily the result of how it pursues its mission, which takes it far beyond fulfilling the typical role of clipped hedges as garden elements for separating or dividing space, privacy or seclusion, screening an unsightly view, or perhaps protection from wind, rain, and sun. Although meeting all these on a high level of artistry, it is to the eyes and mind while resting, that they make their chiefest appeal.

Orthographic Impressions

Fig.1. Whole-house roof plan 1.40

Fig.2. Whole-house ground floor plan incl. enfilade 1.40

Note 10. Enfilade
A common feature in grand European architecture from the Baroque period onward, an enfilade is a series of rooms in which the doors entering each space are aligned with the doors of the connecting space, to facilitate movement through the building, and to provide a vista [a pleasing view] through successive rooms. In a contemporary context, the enfilade is a series of door-windows that allow the heart of the dwelling - the living and dining spaces – to be lightly divided without destroying the concept of a generous, fluid and almost uninterrupted corridor or network of indoor-outdoor spaces and places along the north-south axis.

Fig.3. Ground floor plan @ rear and front reception thresholds 1.20

Note 11. Threshold
A threshold is a transitional zone of movement or pause between two adjacent, rarely identical spaces e.g. inside and outside or spatial statuses e.g. a very public residential street to a very private living space. Contrary to the manner of connecting interior and exterior space today, which is too often and too quickly resolved by nothing more than a solid door; gravel [for its acoustic qualities], in-between spaces, and porte-fenestres [‘door-windows’] are employed to construct a more ambiguous, aesthetically-pleasing transitional zone, that fuses the house with the atmospheric qualities of the garden, nature and street, rather than muting it.

Fig.4. Longitudinal elevation @ street/semiprivate front yard 1.32

Fig.5. Longitudinal section aa @ semiprivate front yard 1.32

Fig.6. Longitudinal section aa @ water bowl/rain chain junction 1.4

Fig.7. Longitudinal section cc and ground floor plan @ front porte-fenetre 1.20

Fig.8. Cross-section gg @ semiprivate front yard 1.12

Fig.9. Cross-section gg @ water bowl/rain chain junction 1.6

Fig.10. Cross-section hh @ front porte-fenetre 1.12

Mood & Ambience

Isometric Cross-Sections

Fig.1. Cross-section gg @ semiprivate front yard 1.16

Fig.2. Section gg @ front water bowl/rain chain junction 1.4

Fig.3. Section hh @ existing front picture window 1.16

Fig.4. Section hh @ front portes-fenetres 1.16

Fig.5. Section hh @ front porte-fenetre/lintel junction 1.2

Fig.6. Section hh @ front portes-fenetre/threshold junction 1.2

Fig.7. Section ii @ front porte-fenetre 1.8

Fig.8. Section ii @ front porte-fenetre: box frame/thermal insulation junction 1.2

Isometric Assembly Drawings

Fig.1. Substructure and superstructure 1.16

Fig.2. Substructure and superstructure exploded 1.24

Fig.3. Timber post-and-lintel skeleton frame @ edge 1.2

Fig.4. Timber post-and-lintel skeleton frame @ midpoint 1.2

Fig.5. Timber post and solid plank floor @ midpoint 1.2

Construction or Working Drawings

Fig.1. Whole-house roof plan 1.40

Fig.2. Whole-house ground floor plan 1.40

Fig.3. Ground floor plan @ front and back thresholds 1.20

Fig.4. Ground floor plan @ deck/living screen junction 1.4

Fig.5. Ground floor plan @ post/water bowl junction 1.2

Fig.6. Longitudinal elevation @ street/semiprivate front yard 1.32

Fig.7. Longitudinal section aa @ semiprivate front yard 1.32

Fig.8. Longitudinal section aa @ rain chain/water bowl junction 1.4

Fig.9. Longitudinal section bb @ semiprivate front yard 1.32

Fig.10. Longitudinal section bb @ timber post-and-lintel skeleton frame [midpoint] 1.2

Fig.11. Longitudinal section bb @ timber post-and-floor structural framework [midpoint] 1.2

Fig.12. Longitudinal section cc @ front facade 1.32

Fig.13. Longitudinal section cc and ground floor plan @ front threshold 1.16

Fig.14. Longitudinal section cc @ front facade/'hidden roof' junction 1.4

Fig.15. Cross-section gg @ semiprivate front yard/street 1.20

Fig.16. Cross-section gg @ semiprivate front yard 1.12

Fig.17. Cross-section gg @ front wall/'hidden roof' junction 1.2

Fig.18. Cross-section gg @ eave/rain chain junction 1.1

Fig.19. Cross-section gg @ rain chain/water bowl junction 1.6

Fig.20. Cross-section hh @ front porte-fenêtre 1.12

Fig.21. Cross-section hh @ front lintel and threshold junctions 1.2

Specification

Engawa Deck

Solid plank floor

44x94x994/1194mm Air-Dried European/English [Quercus Robur] Structural Oak w/ 5x90mm Stainless Steel Framing Nails 34° Round Head [Smooth Shank].

Sub-flooring

47x100x994/3020mm Eased-Edge C24 Kiln Dried Treated Softwood Carcassing Timber @ 400mm o.c., 10x70x70mm Heavy Duty Plastic Solid Square Packer @ 400 o.c.

Slab foundation

150mm Cast Concrete Slab on Grade with 1.2° Slope [Drainage] and 195x195x100mm Plinth, 50mm Coarse Concrete Sand/Sharp Sand Setting, 100mm Type 3 Open Graded Crushed Aggregate, Stable [Uniformly Dense] Soil Base

Post-and-Lintel Skeleton Frame

Post base

125/150mm Granite [Tapered Square] Staddle Stone with 16x230mm Steel Rod [for fixing which protrudes 30mm]

Post

125x125x1950mm Air-Dried European/English [Quercus Robur] Structural Oak

Lintel

125x150x3525mm Air-Dried European/English [Quercus Robur] Structural Oak with Rabbeted Oblique Scarf Splice & 15x15x150mm Draw Pin

External lighting

Mono II Down-Up LED 930 [Dark Grey] Wall Surface Mounted Luminaire

Hisashi Roof with Overhanging Eaves

Ledger beam

75x150x3340mm Air-Dried European/English [Quercus Robur] Structural Oak w/ 12x149mm [WA12199] Wedge Anchor Bolt

Rake w/ overhanging eave

50x200x2000mm Air-Dried European/English [Quercus Robur] Structural Oak @ 34.5°

Rafter w/ overhanging eave

50x100x1800mm Air-Dried European/English [Quercus Robur] Structural Oak @ 34.5°

Sheathing

25x115mm Air Dried Oak Half-Lap Cladding

Interior support

18x38x4800mm Treated Softwood Batten @ 400 o.c.

Shingles

20x142/70x1875mm Carefully Machined Air-Dried Oak Board and Batten

Flashing

0.6x3000mm Polyester Powder Coated [RAL 7016] 25 Gauge Galvanised Steel Counterflashing, 15x15mm Half Clip Fixing, 0.6x3000mm Polyester Powder Coated [RAL 7016] 25 Gauge Galvanised Steel Baseflashing, 0.6x50mm Polyester Powder Coated [RAL 7016] 25 Gauge Galvanised Steel Cleat

Stormwater

5x25x315mm Polyester Powder Coated [RAL 7016] 8 Gauge Galvanised Steel Flat Bar Gutter Bracket, 6x50x100mm Polyester Powder Coated [RAL 7016] 8 Gauge Galvanised Steel Angle 'Valley' Gutter, M12x90mm Hex Head Bolt BZP [10.9], 10mm Grade 80 Short Link Chain.

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Bibliography and Footnotes

1. Kisho Kurokawa [1988]. Rediscovering Japanese Space, pp. 53. Quoted in: David Y. Yen [2012]. Japanese Timber Frame Methodology: Alternative Solutions to Hawaii’s Built Environment, pp. 28-29.

2. Michael Lazarin [2014]. Phenomenology of Japanese Architecture: En [Edge, Connection, Destiny], pp. 133.

3. Jan Gehl [2011]. Life Between Buildings: Using Public Spaces, pp. 31, 113, 121 & 147, 184-85.

4. ‘The theory of ‘prospect and refuge’ seeks to describe why certain environments feel secure and thereby meet basic human psychological needs. Environments that meet such needs will often provide people with the capacity to observe [prospect] without being seen [refuge];’ Annemarie S. Dosen; Michael J. Oswald [2013]. Prospect & Refuge Theory: Constructing A Critical Definition For Architecture & Design, pp. 9. The seminal introduction to this theory is the following passage from Konrad Lorenz: 'Before we break through the last bushes and out of cover to the free expanse of the meadow, we do what all wild animals ... would do under similar circumstances: we reconnoitre [‘survey’], seeking, before we leave our cover, to gain from it the advantage which it can offer alike to hunter and hunted - namely to see without being seen.'; Konrad Lorenz [1952]. King Solomon's Ring. pp. 181.

5. Terrapin Bright Green; William Browning; Catherine Ryan; Joseph Clancy [2014]. 14 Patterns of Biophilic Design: Improving Health and Well-Being in the Built Environment. 4. The Patterns, 4.3 Nature of the Space: Prospect and Refuge.

6. ‘Insertion is an installation-based approach or practice that can establish an intimate house-garden relationship between an original dwelling and a remodelling and yet allow the character of each to exist in a strong and independent manner. As the word suggests, it is the introduction of new, built to fit, intermediating spaces and intermediating elements into outdoor space – for example, the semiprivate front yard and/or private backyard; and beside the symbolic centre of the entire dwelling or ‘space of being’ – the living-dining-working areas. It is at its best when a symbiotic [mutually beneficial] relationship between the crisp new contemporary work and the crumbling antiquity of the existing structure is established and based upon juxtaposition, counterpoint and contrast; and therefore the style, the language, the materials and the character of each are different. The strong relationship of attracting opposites, each complementing and enhancing the other generates a dwelling of a new and greater worth;’ Graeme Brooker; Sally Stone [2004]. Re-readings: Interior Architecture and the Design Principles of Remodelling Existing Buildings, pp. 102-103.

7. Michael Lazarin [2007]. Temporal Architecture: Poetic Dwelling in Japanese Buildings, pp. 106.

8. David Y. Yen [2012], pp. 29.

9. Michael Lazarin [2007], pp. 106.

10. Jan Gehl [2011], pp. 19.

11. Soma Ko Sha [2024]. Traditional Japanese Timber Framing.

12. Ibid.

13. Philip Thiel [1957]. Japanese Influences on Western Architecture. The Journal of Asian Studies, Vol. 16, No. 2, pp. 271-274

14. 'The hidden roof [noyane] is a type of roof widely used in Japan both at Buddhist temples and Shinto shrines. It is composed of a true roof above and a second roof beneath. The second roof is visible only from under the eaves and is therefore called a 'hidden roof' [giving its name to the whole structure] while the first roof is externally visible and is called an 'exposed roof' in English and 'cosmetic roof' [keshōyane] in Japanese;' Wikipedia [2024]. Hidden Roof.

15. Seishisha [2024] Home.

16. Tim Winstanley [2011]. Japanese Precut Timber Construction. ArchDaily.

17. ‘The ‘design for assembly’ [DFA] methodology was pioneered by Boothroyd and Dewhurst at the University of Rhode Island. The method is a design evaluation tool that enables designers to: a. reduce the part count of an assembly; b. design products for easier manual or automatic handling in assembly and; c. reduce the labour and time involved in assembly;’ Robin Kent [2016]. Quality Management in Plastics Processing. Quoted in: Science Direct [2024]. Engineering: Design for Assembly.

18. ‘Now this may not strike you as an intellectual bombshell, and, now that I look back .., I wonder why it was not apparent from the beginning, but people tend to sit most where there are places to sit. Ideally, sitting should be physically comfortable – benches with backrests, well-contoured chairs. It's more important, however, that it be socially comfortable. This means choice: sitting up front, in back, to the side, in the sun, in the shade, in groups, off alone … Now, [we come to] a wonderful invention - the movable chair. Having a back, it is comfortable; more so, if it has an armrest as well. But the big asset is movability. Chairs enlarge choice, and the possibility of choice is as important as the exercise of it. If you know you can move if you want to, you feel more comfortable staying put. This is why, perhaps, people so often move a chair a few inches this way and that before sitting in it, with the chair ending up about where it was in the first place. They are a declaration of autonomy, to oneself, and rather satisfying;' William H. Whyte [1980]. The Social Life of Small Urban Spaces. Project for Public Spaces, pp. 28, 34-35.

19. Heinrich Engel [1964]. The Japanese House: A Tradition for Contemporary Architecture. Chapter IV: Construction, pp. 103-108.

In-between Space 2024

Japanese-influenced indoor-outdoor timber architecture
+ small secluded visual gardens