LOWCOST HOUSING IN GABON
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
In Africa suburbs boomed since the begining of the 1990s development of the middle-class due to industrialization. Gabon is a West African country located on the equator, a major exporter of oil with miles of pristine coastline and aspirations of becoming a prime eco-tourism spot as well as a leader in implementation of green technology in the near future. Gabon faces an acute shortage of housing and needs over 400.000 new homes for its growing population, according to officials. This increase in number of people moving to the capital Libreville and its periphery as well as the new housing programs pose the question of the urban management of the city. The capital‘s obviously restricted living space clearly highlights the need to re‐think the housing and national land management policies. This design studio at the „University of Applied Science Bern“ (CH) aimed at solving the problem of housing shortage by developing a masterplan for a neighbourhood of 500 houses including all nessecary public facilities such as schools, churches, hospitals and adminitstration. Finally we were asked to design a prototype house up to 3 storeys, by using wood as the basic construction material. According to the re-thinking of the current government in using their own natural resource wood as construction material, instead of exporting it, it was important to create positive images how wood could be used in a simple but sustainable way. Panorama view over Libreville - capital city of Gabon
Cameroon
Equatorial Guinea
Rep. of the Congo
Equator Gabon
Libreville Equator
Gabon in its african context
GABON
Rep. of the Congo
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Site map of Gabon with capital city Libreville
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100 km
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
The image of wood in Gabon Due to the fact that wood is regarded as a poor construction material, our prototype houses also aimed to improve this bad image of wood within the Gabonese people. Therefore we worked out the historical meaning of timber construction in Europe, North America and Japan and its rising success nowadays. A collection of best practice examples helped to have a better understanding of the opportunities of good timber constructions. 85% of the countries land surface is covered by forest, which represents a huge amount of natural resource to be used for their national development. A sustainable use of this resource could open up an alternative culture of construction, next to the todays pre-dominant use of concrete, stone and metall.
Pathway into one of the informal townships
Schematic sketches on organization of settlement areas
Reference to metabolistic ideas (Tokio bay Kenzo Tange)
Analysis and interpretation of todays neighbourhoods in Libreville
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
Interdisciplinary work The project was organized as an interdisciplinary work between architects and timber engineers from the „University of Applied Science Bern“ and the company „Ecowood“, which represents the economic part and intends to establish a culture of timber-construction in Gabon. Therefore we built teams consisting out of architecture students, timber engineer students and experts from Gabon, who were providing the groups with the important cultural, social and climatic knowledge about their country. The company „Ecowood“ mainly produces their glue lams and other timber products, out of remainings that are left from the forest cuttings. These remainings could be already enough to establish an alternative constructive culture.
Inside the workshop of the company „Ecowood“ in Libreville
First 50 houses
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2030
2040
The growing neighbourhood
Learning from wood - workers of the company „Ecowood“ in Gabon
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
„Everything begins with the forest that provides the material and is a decisive climate factor if wood is sourced in a sustainable way from well-managed forests. Residential building construction with wood is now changing, focusing on green supply chains and resource-optimized engineered systems.Timber construction is an efficient method of CO2 storage, as long as the material is obtained using responsible methods of forest cultivation (plantations) and from a certified source that is not too far away (to avoid transport-generated greenhouse gases).“ Sustainable Construction for Urban Infill Development Using Engineered Massive Wood Panel Systems, Steffen Lehmann, University of South 3 Australia
Covered land surface: 30 %
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Masterplan - elements Covered land surface: 60 %
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Schema of mainstreet and secondary equal grid Green stripe for gardening and public needs like waterpump stations Market place and institutional facilities Areas for potential growth Housing Public facilities (shops etc.)
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The growing neighbourhood 1 Plots in the beginning 2 Densification space 3 After densification
The problem of garbage organization is one part of the current urban managment
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MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
Conceptual masterplan Our proposal is not located in an existing context, which leads to a diagrammatic and schematic organization the „500 houses neighbourhood“. Based on the question: „How to develope a complete new settlement in the periphery of Libreville?“ our masterplan works with the assumption of an ongoing growth of the capital city. Having a look on the metabolistic ideas of the 1960th in Japan, we considered the fact of a changing society as very important. A strong backbone (main boulevard) provides every neighbourhood with water, electricity and streets. This ateria could connect the new settlement with the city of Libreville and acts as a frame for smaller units, that are plugged into this backbone.
Street sections before densification with green stripe
Diagramm for radial equal distribution of public needs
Street sections after densification
The absence of a masterplan causes ineffective land-use
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
On each side of the central boulevard we placed smaller areas for housing. In order to allow an extension of the houses, we established bigger plots. Firstly they only may have single storey houses, which later could be extended or replaced to densify the city. In case of building higher houses, the plots are big enough to let the necessary amount of sunlight into the buildings. Although we designed a major boulevard with a central market place, we tried to distribute other public facilities in an equal way, to avoid disadvantaged areas in the neighbourhood. Every cross road is formed by bigger corner buildings and represents a meeting point for the quarter with shops, medical aid stations and communal facilities.
Excerpt of conceptional Masterplan
The plot as a frame for individual freedom
Reference 1 - Martin Rauch (AU) studies on low cost housing in Zambia 1984
Reference 2 - Shigeru Ban (JP) post tsunami houses in Sri Lanka
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
Urban planning for prototype houses In a second step we were asked to put our prototype houses in the context of the masterplan. While the masterplan stays very diagrammatic, the houses itself are developed close to the existing social, cultural, economic and climatic conditions. The urban planning of my housing represents a clear division between the public and private „face“ of a house. Regarding the vital streetlife in this culture my house offers a calm retreat for families up to 4 children. In order to give a remarkable shape for the street the pitched roofs are emphazising the entrances. One unit is divided into four plots for four houses. Each is provided with a private outside space for gardening or waterstorage. If necessary the structure allows to close the private space. Initially the inner cross road may represent a common space, e.g. the „Corps du Gard“. The idea of the framed piece of land contains the possibilty for different individual usage of it, by respecting the public character of the street.
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Studies on roof shape and street character 1 Street character - housing units with pathway in between 2 Street character - duplex houses
Axonometry of one housing unit with 4 plots
Site plan of prototype houses
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
Prototype house Regarding the major idea of urban planning, also the inside of the house is clearly organized into a more public and more private zone. You access the house via the main entrance leading to the court yard. A stair, which is acting like a filter and also meeting point for the neighbours, is guiding you on the terrace. The terrace symbolizes the heart of the house. Kitchen, sanitary facilities and the bed rooms are arranged in a L-shape, arround the half-open terrace. While the terrace is going to be a part of the garden, the private rooms are close to the rammed earth wall, which provides them with a cool climate and intimicy. Additionally a second entrance leads into a small shop, which may be used for the families sales activities (handycraft, food) and represents the more street orientated part of the house.
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Sidewalk 2nd entrance
Shop Filter
WC2
WC1
Mainentrance
Kitchen
Parents
Terrace
First atmospherical sketches A
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Kids 2
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Kids 1
Rainwater Storage
Floor plan
Elevation of the entrance side
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
While the rammed earth wall stands for the representative outer frame of the unit, the light wooden fill-in symbolizes the individual freedom of the owner. The wooden roof lays like a crown on the solid rammed earth walls and could be associated with a soft inside, which needs to be protected. This more introverted image of the house creates the counterpart of the active street-life of Gabonese people. Although traditional Gabonese values are adopting to a western way of life, they still care about them. The patriarchal thinking still dominates lot of families, which becomes apparent in having two entrances, one for man and one for woman who is responsible for the household and the children.
1 Axonometric view
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1 - 4 Studies on height & proportion of rammed earth wall
Elevation longside
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
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Dig out the soil and keep soil and stones at site. Up to 80cm deep, this hole can be digged out by „human force“ (or if possible by excavator).
Set Gabion foundation filled with stones found in the ground of site. Use Bamboo pipes as reinforcement, that are fixed into Gabions. Put a 4-5cm layer of concrete on top of gabions, to get a plane surface for rammed earth.
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Construct rammed earth walls with a wooden horizontal climbing formwork. Thickness of wall = 1/8 of height. Place every 3 layers brick tiles for rain protection.
Build the floor by layers of stones, gravel, sand and light loam. Use wood grid structure to avoid cracks.
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Lift up the primary load barrying wood structure. These frames have to be strongly connected to the rammed earth walls. Bracing is done by diagonal 10/5cm boards inbetween the posts.
Horizontal beams keep the distance between primary frame. Use brackets for holding them in correct height.
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Insert the outer frame for the window elements by screwing them into the load barrying post.
Step 8 and 9 have to be done simultaniously. Place the vertical 10/5cm sticks for the interior walls in regular distance of 50cm. Additional sticks at rammed earth wall and doors.
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Use the plywood panels to gain correct distance between sticks. Nail or srew the panles into sticks.
Nail the 200/125/2,5cm plywood panels on the roof beams of the primary frame. It acts like additional bracing of roof. After, nail 6/4cm wooden bars on the surface in distance of max. 50cm.
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Install the aluminium roof. Cover the srews by plastic or other water resistance material.
Insert the prefabricated window elements by srewing into outer frame. After screwing the toppest rail into the upper beam and embed the lowest rail into concrete on the floor, finaly push the sliding window panels into the rails. Use wax or soap to keep a light sliding of the window panels in the rails.
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Materiality 1 - rammed earth 1 Horizontal brick tiles (against rainwater) 2 Openings by plastic pipes 3 Horizontal brick tiles (against rainwater)
Building process
Section B-B longside
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
Aluminium Roof
Wooden Support Bars
Wooden Roof Cladding
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Shop Entrance Stone Stairs
Loadbarrying Frame Construction
(Post & Beam incl. Bracing)
Bracing Clip in Prefab Window Panels Rammed Earth Wall
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Outer Frame Window Panels
Movable Window Panels
Terrace Entrance Stone Stairs
Service Shelf Interior Walls (Wood Panel Construction)
3 Floor Construction
(Loam, Sand, Gravel, Stone, Earth)
Foundation (Gabions)
Materiality 2 - Timber types in Gabon 1 Breu-Vermelho 2 Acapu 3 Okoume
D1 Cross section A-A
Exploded view
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
It was important to create a construction, that is simple enough to be built by the owners family, without any expensive professional help. The idea to use rammed earth refers to the possibility of using the dug out dirt. The building material is at the building site and doesn‘t need to be transported. Finally we had to design a small users-manual for our prototype house, guiding through the most important steps of the construction. Roof Aluminium Roof Wooden Roof Cladding Wooden Beam 100/150 Wooden Support Bars
Frame & Clip in Window Window Lamellas 25/60 Inner Window Frame 35/35 Covering Lattice Outer Window Frame 100/50 Diagonal Bracing Board 50/100 Horizontal Wooden Beam 100/100
Rammed Earth Wall Covering Brick Tile Support Board Bolt 12/400 Bamboo Pipe Reinforcement Rammed Earth (Soil, Sand, Gravel) Brick Tile
Floor
Rammed Earth Wall Foundation
Light Loam (with wooden Grid, to avoid cracks) Sand Fine Gravel Gravel Stones Compacted Earth
Rammed Earth Wall Water Proof Bitum Layer Concrete Support Layer 40mm Gabions Bamboo Pipe Reinforcement
Sketches on techniques of vertical formwork
Perspective view main entrance
Segmental elevation
D1 - detail section rammed earth wall
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
To find an appropriated material representing the rammed earth wall in the 1:20 model, tests were made with mixtures of several ingredients, such as gypsum, cement, sand and other add-ons. Addionally I used nails and thin metall wires to reinforce the thin walls. By building this delicate walls, I obviously understood the importance of a good reinforcement for the real rammed earth walls, which could be out of bamboo pipes and located at least at the corners and openings of the wall.
Model 1:20 - front view - walls made of a gypsum-cement mixture, wooden parts out of balsa and veneer
Material test for model 1:20 mixture of: 1 2 3 4 5
gypsum 50% cement 50% pigments yellow pigments red nail, wire reinforcement
Material tests for model 1:20
Model 1:20 - interior view on the terrace and the bed rooms
MA 3 Berner Fachhochschule Prof. Fidanza/Ebeling Lowcost Housing in Gabon
“The difference between good and bad work lies in an understanding of that which is shared and common and the ability to transform these ideas into forms and spaces which are both useful and satisfying within the community in which the work is located.” Jo Noero, Noero Architects Cape Town, South Africa „Common Ground / Different Worlds“ Venice Biennale 2012
Model 1:20 - court yard view
Model 1:20 - entrance door into shop
Model 1:20 - prefab window panels providing the rooms with enough light and ventilation