Where Rwandan soil rises to meet the sky, divine light bridges the gap between heaven and earth and all come together as one.
The chapel of the Crossing marks the meeting of God and mortal. Tutsi and Hutu; local and travel; all gathering together to celebrate the glory of the divine.
Winding Path Community Centre
Client
ARCH Sharing
Status
Complete - Competition
Location
Nepal
Responding to the Community Centre’s inevitable change in site, our design process delves beyond response to sloped Nepalese landscapes: the earthquake-resistant Community Centre concept adapts to site specific contours, views and landmarks. Not a singular structure to be replicated on any site of similar typology; rather a creative process that will yield a unique design from consistent architectural principles that belongs only to the final site.
With intent to create a building that enhances rather than occupies the stunning valleyed landscape, we endeavoured to sculpt a fluid, winding form: meandering up the site to shape a sequence of external and internal spaces linking road access to hill-top view. Mindful of the desired heights for the various internal spaces, two contours encompassing a 4 metre rise, oriented to welcome the valley views, were selected to define the main building. An S-shaped extension of this form winds down the hill around three site trees to connect to the road; as well as bending back on itself to shape serene external space overlooking the valley from the top of the site. Beyond reducing visual footprint and reflecting the locally popular terraced housing, cutting the building into the site serves as an earthquake-resistant technique: significantly reducing the impact of seismic activity.
To shape functional space, bamboo-reinforced cob and rammed earth were selected as the primary construction methods due to their proven earth-quake resistance, low cost, insulative properties, and low-skill techniques that can easily be taught to and adopted by the local population. Rammed earth creates steadfast retaining walls and floors, whilst cob construction permits the formation of fluid earthquake resistant forms sculpted by hand into walls, benches, chimneyed earth stoves for the kitchen that combat smoke issues within traditional rural set-ups… endless possibilities. The soft earthen interiors evoke an enticing spatial quality that is at once winter-warm and summer cool: a space of comfort and wellbeing. Regulated windows and doors open the interior to sunlight and breeze, whilst recycled glass bottle portals emit patterns of softly-coloured light along the wall top; reflecting the site cut line moulded in earthen hues along the outer wall face. The all-encompassing twisting roof derives from a dual requirement: to optimise water collection and views. Framed by a bamboo column-truss hybrid structure, the triangulated roof panels direct rain into three water tanks positioned to provide water to the main floor/kitchen, amenities, and drinking well welcoming passers-by into the site. An integrated waste treatment and greywater reuse system ensures that no substance is wasted. The terraced aquaponics system formed into the central court provides vegetables and fish for the kitchen; actively teaching the local community an affordable method to grow twice the vegetables per square metre than inground methods whilst providing a steady supply of fish.
Envisioning the possibilities of such affordable and locally buildable earthquake-resistant structures we can imagine entire villages formed of winding inter-connected buildings; homes, schools, all manner of community spaces dotted under water-collecting roofs traversing terraced hillsides.
analysing site |
selecting contours
DEFINING FORM |
CUTTING FLOOR PLATE
SHAPING SPACE|
EXTRUDING WALLS
WATER COLLECTION |
OPTIMISED ROOF FORM
Earthquake resistant techniques
SCALE OF THE COMMUNITY
SCALE OF THE ARCHITECTURE
SCALE OF THE DETAILING
Post-devastating 2015 earthquake local confidence in traditional construction techniques and materials understandably fell dramatically; largely founded in the widespread belief that the architecture of Nepal’s hills was to blame for the significant loss of life and property. Before the beautifully earthen architecture of rural Nepal is thrown out in favour of prefabricated housing and bulky concrete bunkers, however, we believe it is not time to give up on old methods just yet. In fact, all they need is a bamboo-reinforced revamp.
Rammed earth and cob construction - sturdy vernacular staples of many cultures and climates –already boasts moderately effective earthquake resistant properties when properly constructed. When bamboo reinforcement is added into the mix their construction stands to remain habitably safe beyond an earthquake higher on the Richter scale than 2015’s. A study conducted at the University of Sydney in Australia successfully tested a half-scale two storey bamboo reinforced cob house to survive a 7.8 magnitude quake, accounting for accurate aftershocks. Low-skill vernacular construction techniques utilizing abundant local materials simply adapted into efficiently earthquake resistant structure certainly seems an excellent method to teach the local Nepalese population.
Beyond choosing appropriate construction techniques and materials there are many techniques one can adopt to better the earthquake resistance of a structure. Cutting the building into the site to form a stable, flat foundation is a fitting terraced means to greatly reduce the seismic forces acting on the structure; in addition to providing raw material for both rammed earth and cob construction. This method involves installing a sturdy retaining wall separate to the building that eliminates the effect of sideways forces from the quake and catch falling debris. The foundation should extend deep into the slope to give lateral support to the soil, whilst careful thought should be given to drainage to avoid water seepage into the soil system under the building’s footprint. The roof should act as an independent structure as they typically experience a different frequency of movement than walls; detaching eliminates risk of heightened horizontal force. Perhaps most promising approach architectural design-wise is the fact that organic, curvy wall forms in a segmented plan are the most earthquake-resistant as they eliminate sharp corners that become severe weak points during a quake. Furthermore, fixed furniture minimizes the danger of falling objects whilst increasing the walls’ strength; an excellent marker for cob construction much loved for its ability to flow seamlessly from wall into window seats, shelving, chimneys – you name it.
At the most intricate level measures can be taken to maximize a building’s chances against an earthquake. Beyond the introduction of bamboo framing set deep into the foundations the addition of strip bamboo ‘ladders’ running horizontally at 300mm centres greatly improves the reinforcement potential. Furthermore, seismic bands running along the levels of the plinth, window and door lintel, and wall top significantly assist in maintaining the structural integrity of the walls during a quake. In the way of traditional cob construction, a stone stem wall running over concrete foundations is the most effective means to achieve the lower seismic band with waterproofing action and added benefit of locally sourced material.
The openings for windows and doors should not exceed 1000mm – however this is not to say that the smaller openings will be light-restrictive as cob can be formed into chamfered window frames that maximize light collection, whilst the softly polished finish maintains beautiful light refraction properties. To form a larger-span independent roof there are many possibilities within geometric bamboo truss structures – many that utilize simple tie fixings that can easily be achieve by the most inexperienced craftsperson with minimal training.
