This project represents our attempts to synthesize a structural system that is highly efficient, responsive to programmatic changes, and self-contained. Our system is re-peatable and modular, and its parts tie into each other to make deviations from stand-ard conditions absorbable by the integrity of the rest of the system. The module is de-fined by a column rising up from the floor and branching out into a hexagonal shape, from which additional members are drawn to connect to neighboring hexagons in a linear truss shape. This is augmented by a contrasting network of steel cables connect-ing the columns around balconies, atriums, light wells, and other cutouts, allowing spatial variety without endangering the wood’s structural integrity.
In the process of the case study many lessons can be gleaned about fabrication, spatial arrangement, and unique construction methods that enable the forms desired. For this series of case studies we focused on structures that exploited the tectonic or formal possibilities of lumber to their fullest, so that we might be inspired by the most fanciful or innovative techniques of working with this ubiquitous material.
Boxing Club, FT Architects
Various residences, Natural Space Domes
Domes
with BuroHappold
Natural Space Domes is an American firm specializing in the construction of light wood domes for residential use. The prototypical dome diagrammed here shows many of the salient characteristics of their structures, including 16” thick wooden frames and windows or doors that can be inset into the modular panels. The modular nature of the triangular panels allows for responsiveness to the environmental context.
A
AIR OUTLET
VENT OPENING
DOUBLE 2x8 STRUT
3” AIR SPACE
COOL AIR
3” AIR SPACE
COOL AIR B B
BASE VENT
DOUBLE 2x8 STRUT
COOL AIR
EXTERIOR LOAD-BEARING
2X6 TYP.
VENTILATION NOTCH
3/4” PLYWOOD GUSSET CUT FROM EXCESS SHEATHING
INTERIOR 2X4 NAILER STRUT
SLEEVE TONGUE HUB
Downland Gridshell is a conservation workshop for the Weald and Downland Living Museum, an outdoor collection in the south of England tracing the evolution of dwellings in the British Isles. The assortment of dwellings traces from Paleolithic through Tudor times, making restoration efforts highly specialized. The Gridshell responds to these predominantly woodframed constructions with a high-tech structure made of 4x4 wood members held in a spherical shape by steel plate joints (below). The unconventional form allows for unabridged interior space with great interior volume. The construction process was unique in that the wooden diagrid was built flat and orthogonal before the edges were lowered from the ceiling height for the structure to ‘fall’ into place. In this way, the Gridshell exploits and pushes the boundaries of wood construction techniques to create a form thoroughly unconventional yet suited for its purpose.
A
THREADED RODS FOR SECURING STRUCTURAL LATHES
ADHESIVE-FREE ASSEMBLY ALLOWS WOOD TO FLEX UNDER LOAD
BFRESH WOOD LATHES
METAL JOINT PLATE WITH THREADED HOLES
WATTLE + DAUB COATING PROTECTS WOOD FROM MOISTURE AIR GAP INCREASES THERMAL MASS AND REDUCES MOISTURE DAMAGE
OVERHUNG CENTRAL ROOF PROVIDES EXTRA SHADING AND PROTECTION FROM BUILDUP OF DEBRIS
OVERSIZED SLIDING GLASS DOORS ALLOW WORK ON LARGER ARTIFACTS AND PASSIVE VENTILATION
POLYCARBONATE CLERESTORY
WINDOWS ADMIT DIFFUSE SUNLIGHT FOR USERS
DOUBLE-SLATTED WOOD PLANK CLADDING SHEDS PRECIPITATION AND CREATES UNIQUE PROFILE
OBLIQUE BIAXIAL GRIDSHELL ABSORBS LOADS FROM ALL DIRECTIONS BY FLEXING B
The Boxing Club is a boxing gym designed for Kogakuin University’s athletic campus in the western suburbs of Tokyo. Its austere exterior belies a vaulted interior structure made with extended wood columns referencing traditional Japanese timber construction. Tensioned rods are bolted at each end and squeeze the cantilevered beams to keep them in compression. The rectangular floor plan is predicated on the dimensions of a boxing ring. Translucent corrugated plastic covers the end facades, creating a jewel-box effect at night that allows the interior lighting to silhouette the wooden structure against the exterior. The vault created by this system is extruded linearly over the ring to establish an introspective space that coddles athletes in the heat of their sport.
POLYPROPYLENE SHEETS ON N AND S FACADES ADMIT DIFFUSE SUNLIGHT AND ESTABLISH AESTHETIC IDENTITY
FULL-LENGTH SPARS ABSORB LONGITUDINAL LOADS
BOXING RING DIMENSIONS GOVERN ENCLOSURE SIZE
INSULATED ROOF AND WALL PANELS FORM MOISTURE AND THERMAL BARRIER
MECHANICAL FASTENERS ECHO TRADITIONAL METHODS AND ARE SUSTAINABLE
TENSIONED RODS HOLD WOOD MEMBERS IN COMPRESSION FOR LATERAL LOADS
BUILDING ORIENTATION MITIGATES HARSH DIRECT SUNLIGHT
BOLTED ROOF BEAMS ABSORB SHEAR LOADS
PANELS BARRIER
OPERABLE WINDOWS PROVIDE PASSIVE VENTILATION
The following are a collection of models demonstrating the various experiments which led to the development of one highest potential prototype. Throughout these experiments, we were concerned with the values of spatial flexibility and aesthetic uniqueness.
Our initial experiments in building systems were guided by a desire to minimize the structure, whether in plan or in section, and combine that with an elegance and novelty that distinguishes it from normal timberframe construction. From top to bottom:
A model that focuses on the joinery techniques of wood construction. Doubled dimensional lumber creates more rigid columns and allows a spacer to be placed in between to support floor joists. These joists extend past the outermost columns to provide a regular attachment point for facades that can provide solar shading and support a double-skin envelope.
A model that uses trusses and diagonal braces in all three axes to provide impressive structural rigidity and open floor areas. The slenderness of the vertical columns is compensated on the braced facade, while flat X-braces infill the space between trusses to support high floor loads.
A model based on a diagrid facade backed up with a solid shear wall to create an inner occupiable space and a perimeter circulation path with views of both structural systems. This module takes the double-skin idea to its logical conclusion by making it so thick as to be usable. This method concentrates the structural system vertically as opposed to horizontally, taking a different approach to minimizing intrusions into usable space.
The most open and flexible system was the first of the three prototypes on the previous page, but it was lacking in lateral and shear resistance. We came up with the idea of bracing branching out from each column to create ‘branches’ that could be tessellated for regularity. This system had the further benefit of decoupling the facade entirely from the structure, unlike the other two initial experiments, which makes it possible to adjust the facade more freely in response to environmental conditions as seen in this interactive model.
Through the evolution of our experiements, we landed on a branching column system that is based on a hexagonal plan offset by diamonds. We produced various versions of this: 1A and 2A based on this pattern, and 1B and 2B based on tessellating hexagons without diamond infill. In both cases, version 1 is a ‘pure’ interpretation of the pattern, while version 2 is reinforced with additional orthogonal elements which we determined could be reduced to cable ties holding the wood elements in compression.
The tectonic and spatial similarities between a branching gridded column and a spaceframe mean that the transition between the two, as well as the full use of their strengths, can be accomplished with the simple addition or subtraction of cable and cable and columns respectively. On account of this, various programs can be accommodated by creating variety in the section or plan of the aggregation. We provide some examples of possible uses on the following pages.
8” x 8” HEAVY TIMBER COLUMN
HEAVY TIMBER COLUMN BRANCHES
TIMBER HEXAGONAL GRIDDED JOIST
TRIPLE LAYER CLT FLOOR
A B C D E
SUNLIGHT ENTERS THROUGH CLERESTORY WINDOWS ON THE FACADE
STRUCTURE INDEPENDENT OF FACADE, ALLOWING THE FACADE TO BE ANY FORM OR MATERIAL
B C
D E
PYRAMIDAL HEXAGON SPACE IN BETWEEN BRANCHES PROVIDE SPACE FORE MEP SYSTEMS WHICH CAN EITHER BE HIDDEN OR EXPOSED AS DESIRED
STRUCTURAL BAYS ARE ORTHOGONAL DESPITE HEXAGONAL TESSELLATION
POTENTIAL INFILLS OF BRANCHES WITH OPAQUE AND SEMI-TRANSPARENT MATERIAL TO CHANGE THE LIGHTING AND SPATIAL QUALITY
A
What results from the hybridization is a flexible system that capitalizes on the vertical character of the branching column bay and the lateral space frame bay to produce a spectrum of spatial and structural dynamism that can accommodate diverse programmatic functions.
Details of the model show how our module prevents the overarching monotony of repetition through the unduluating profile of the branches as well as the lithe elegance of the cables keeping suspended frame elements in tension.
