Westridge High School is situated in Mitchell’s Plain in the Western Cape and has recently celebrated its 30th birthday. There are 1 000 learners at the school. From a community with social problems including poverty, gangsterism and drug abuse, particularly the use of Tic (Crystalmath drug).
The major challenges this school faces include the lack of funds –the school is a fee-paying institution, it only manages to collect a small portion of the fees from parents.
Some of the children display severe behavioural problems such as absenteeism, drug abuse and there is also a high incidence of teenage pregnancy.
School property is often vandalised and teachers feel discouraged because of the many non-academic issues they have to deal with. Sport facilities are lacking at the school because they have been allowed to deteriorate.
Westridge High School has never deviated from its policy of accepting all the eligible learners resident in and around their immediate surroundings irrespective of religion, race, academic ability or financial means.
Their emphasis has always been on the holistic development of the learner, exposing them to as many facets of life as possible. Many academic achievers, celebrities and national sports stars are proud to claim Westridge High as their 'alma mater‘.
Issues
• The school has been graded as a Quintile 5 school (An up market suburb community with well –off facilities in terms of their socio –economic status )despite the poverty of many of its learners.
• The school receives fees from about one-third of its learners and no government funding.
• Vandalism results in the school having to spend funds on repairs instead of educational material.
• Some of the learners display anti-social behavioral problems.
• Climate regulation in the classrooms is poor, it is very cold in winter & very hot in summer.
• Classrooms have poor natural lighting.
• The school does not have a hall, they use one of their classrooms to host functions.
Objectives
• Simplicity: the concept must be simple, use relatively low technology and be easily replicable.
• Adaptability: the system must be flexible to facilitate different activities & conditions.
• Job creation: local unskilled labour can be employed.
• Maximize use of natural, locally sourced materials.
• Versatility: The building must be able to fit on any context.
Concept of a classroom
The idea of an ideal classroom is one that can serve as a multi-purpose space. A room that is flexible but true to its function as a classroom. It is flexible in terms that it can host functions of the school or the community and can fit into any context. It must provide excellent thermal & acoustic properties, also allow sufficient natural lighting & ventilation. The aim is to develop a modular design which can be placed onto any site.
Design concept
The purpose of the spine is to allow for flexibility of the body and protection of the neural elements. All main organs are connected via the spinal cord which is incased by the spinal column.
The approach to this design was to allow for flexibility of spaces, light, ventilation, acoustic control, services, energy & structural co-ordination from a central axis. Similar to the spine.
The unit comprises of two flexible spaces either side of a service spine that are of suitable size to serve as halls for the school. During school hours these space are divided by means of sliding doors to form four classrooms & these classrooms are held together by a spine that acts as a connector hosting all the components of the building.
The spine also functions as storage. It is a good acoustics buffer between opposite classrooms.
The classrooms open up to the external environment to create a relationship between inside & outside by means of sliding doors which also allow for future extension to be done without having to break down walls i.e the doors are the external walls.
Use of Spaces
The spine holds all services including storage, ablution facilities, ventilation, electrical pipes, and most importantly assists in supporting the roof structure. Sliding doors stack into the spine allowing different spaces to be used in a variety of different ways whilst maximum natural lighting and ventilation is achieved. Sliding stacking doors which perform the role of walls (when closed) are insulated panels which give good thermal and insulation properties. A single classroom allows a minimum of 20 pupils to a teacher & a merged classroom allows 40 pupils. When the classrooms are merged the student can be orientated towards the sliding doors which act as a writing board when closed. The design is planned in such a way that the spaces are comfortable & flexible enough for the school to rent out as a hall to host communal functions to generate income for the school.

Elevations

In response to negative social issues such as gangsterism, drugs and teenage pregnancy, the facades of the classrooms are left bare to allow students and teachers to place posters & create art effects to promote awareness of such issues. By doing so it will help give them the opportunity to take part in any other current issues, thereby creating a sense of ownership.
The internal walls of the classrooms are left uninterrupted to allow students & teachers to place educational poster & advertising media. When the space is let out for private use the displayed media can be easily removed for decorative purposes.
The spinal storage system is enclosed with sliding panels that houses the teaching boards. When opened the teaching boards separates to allow access to the storage spaces.
Site
The classrooms are placed at the northern edge of the site to gain easy access from parking and existing classroom blocks & to create a relationship between the community church & residents of the wider community. The site is relatively flat with sandy soil conditions & vegetation.
The classrooms are orientated to the North to make use of solar heat gain through the translucent sheeting to the colder side of the building.
Elevations
In response to negative social issues such as gangsterism, drugs and teenage pregnancy, the facades of the classrooms are left bare to allow students and teachers to place posters & create art effects to promote awareness of such issues. By doing so it will help give them the opportunity to take part in any other current issues, thereby creating a sense of ownership.
The internal walls of the classrooms are left uninterrupted to allow students & teachers to place educational poster & advertising media. When the space is let out for private use the displayed media can be easily removed for decorative purposes.
Sustainability:
Ventilation
Solar radiation penetrates trough the translucent sheeting into the ventilation duct, generating heat. This allows suction of air to occur, thereby generating constant air movement. The air moves from outside into the classrooms & then sucked through the grills into the duct to be extruded outside.
The sliding doors & high level windows allow maximum air movement through the building, this eliminates the need for air conditioning & to promote natural ventilation.
Passive solar devices use little, or no other power source than sunlight collection.. At any given time, the temperature in the duct is 10 to 20 or more degrees warmer than the rest of the building. In the winter, this can help heat the rest of the building on a sunny day.
Energy
Solar panels are placed on the roof on the northern side of the building to provide electricity whilst the batteries & electricity box are housed in the spine. Natural lighting is gained through the high level windows, the surrounding translucent sheeting & the glazed sliding doors. To create more light in the building fluorescent lighting powered by the solar panels is recommended because it covers more ground & lasts longer than the conventional lights.
Extrusion of hot air
Heat generated in the classrooms is controlled by air constant air circulation.Cool air enters into the classrooms & hot air is pushed up & sucked into the air duct then extruded out of the building following the wind direction.
Natural light
Natural lighting is achieved by having high level windows & wide translucent sheeting. The external sliding doors have vision panels to the lower ends which draws in additional natural light. By placing windows at low and high levels helps reduce direct sun glare in classrooms. The space left between high and low windows can now be used to add teaching media, boards, posters and decoration.
Materials
The building is mainly built with sandbags. The sandbags are plastered over externally and timber boarding is used to form an internal face, along with translucent sheeting to maximize natural light penetration. This cost effective solution reduces the cost of building materials, reduces building time and considers the involvement of the community in the building process. This structural system consists of timber lattice frame combined with a sandbag construction as infill for the walls of the building. The timber beams have inlays to provide tensile strength, thus improving the structural integrity of the system.
The Sandbag System exhibits tremendous thermal stability. The occupants will be kept cool in summer and warm in winter, due to a high thermal mass. Millions of small air spaces between the grains of sand are responsible for comparatively good thermal insulation.
It also has excellent sound-absorbing properties which help to provide a measure of acoustic privacy between different units. Another feature that guarantees comfort and a healthy climate are the “breathable” walls. Sand, the geotextile of the bags and the earthen plaster are vapour permeable.
Due to the enormous weight of sand the building is very wind resistant. And the unique quality of sand to absorb impacts makes the walls absolutely bulletproof.
Finally, and of paramount importance the plastered sandbag walls are fire resistant.
The above characteristics are documented by various lab testing’s mostly carried out in South Africa. And practical experience of people living in sandbag houses is proving these great qualities.
The roof is constructed with a conventional timber truss & corrugated sheeting system. An insulated plasterboard ceiling is used for sound and thermal insulation.
Ecobeams
The frame of the building is constructed with Ecobeams forming the inside and outside walls. The uprights in the wall are spaced approximately 900 mm apart. Any type of window or door can be mounted on the frame. The Ecobeam is designed to reduce the use of material for the necessary framework structure of the building to an absolute minimum.
Sand
Sand can be found in places all over the world and is considered to be an unlimited resource. It has the ability to absorb and resolve all kinds of impacts.
Bags
A good adhesion and durability are the most important qualities for the choice of bag material. A thin non-woven geo-textile made from polypropylene or polyester is commonly used for sandbags. There is sufficient friction between the bags to prevent them from slipping and secondly, it guarantees good adhesion of the plaster to the bags. The plaster penetrates the bag and never fall off. Another positive feature of the geo-textile is that it is vapor permeable due to the millions of small holes between the fibres.
Wall finish
Nearly all buildings built in South Africa are finished with a classical cement plaster. To make the building most ecological and healthy, clay and/or lime plaster are a perfect choice. Also, plaster provides a smooth finish to apply media.
Floor & foundation
Double layers of bags filled with sand stabilized by cement can form a very simple foundation. The sandbags can be laid directly on a hardcore sub-base. To omit concrete and steel re-enforcement makes a big impact on reducing CO2 emission and is also cheaper. The same principle for the foundation can be applied for the floor.
Simplicity of Construction
The construction technique can be learnt easily within a few days by people without experience in the building trade. A regular “builder” would pick it up immediately. The relatively small sandbags weigh only 7 kg and the Ecobeams are also very light in weight and can be handled easily by one person in all phases of the construction. 1500 bags is the equivalent of 3000 bricks over the same area in a cavity wall construction. Also no electricity is required at the construction site and only minimal amounts of water and cement are necessary. All members of the community can be involved, thereby creating a sense of ownership, belonging and contribution in the participants.

Location