Projects > Sierra Leone > Paramedical School
Paramedical School
Sierra Leone
Background
In 1980 we were asked by the EU office in Freetown to prepare designs for a new paramedical school to be built outside of Bo Town in the Eastern Province of the country 150 miles from Freetown. This was to be a new school that was being set up to train paramedical workers who would work in rural villages where it was difficult to place fully trained doctors.
The school was built on a very large, sloping site outside of Bo Town. It was a self-contained campus with administrative offices, teaching spaces, dormitories for male and female students and a number of staff houses. The offices, classrooms and student dormitories occupy one part of the site with staff houses in another part.
The school facilities were designed around a central covered route with covered links to the individual buildings. The covered way ran north-south with the buildings perpendicular to it so that all of the buildings were oriented north-south thereby reducing solar penetration into rooms. Changes of level form one end of the site to the other were taken care of by steps in the central covered way and changes of level across the site by steps down to buildings on the lower side of the covered way. The admin buildings were at one end of the covered way, near the entrance to the site, the teaching buildings were in the centre and the student dormitories were at the other end. The staff houses were located at the rear of the site away from the teaching accommodation.
The planning of the buildings was based on a grid based on the span of the lightweight steel purlins (for details see below) which were supported either by cross-walls or for the larger, teaching spaces, steel portal beams supported on block-work piers.
The admin and teaching buildings (and staff houses) were all single-storey and the dormitories were two-storey. All buildings were constructed of load-bearing blockwork, plastered and painted with RC ring beams but no RC columns. All buildings had large roof overhangs to reduce solar penetration into rooms and also to keep the rain off of the walls and windows in order to reduce maintenance costs. There were no roof gutters (which get blocked and provide breeding places for mosquitoes) and rainwater was collected in storm-drains around the buildings and in a main drain along the central route.
The buildings were accessed either from access verandas (and balconies in the case of the two-storey dormitories) or from the ends of the buildings and had full width windows (aluminium louvre units) between cross-walls on both sides of the buildings in order to provide maximum cross-ventilation. The rooms in the dormitories had full width louvre windows on the outside walls and full-height timber louvre doors and fixed louvred panels on the veranda/balcony side again to provide maximum cross-ventilation.
Profiled steel sheets were used for roofing supported on triangular long-span steel purlins made of reinforcing rods with two rods at the top and one at the bottom (similar to those used in the University Village in Zambia but used the other way up). The roof sheets were supported on the two top rods (and this allowed us to omit one purlin at the centre of the roofs) and the timber ceiling battens were supported by the single rod at the bottom of the purlins. The ceilings followed the slope of the roofs providing additional height to all rooms. The walls at the eaves stopped at the underside of the purlins and the gaps between the tops of the walls and the undersides of the roof sheets were closed with mesh panels that allowed the ceiling spaces to be ventilated.
This project illustrated what were then my main concerns when designing educational (and other) buildings in tropical countries: simplifying construction and reducing costs by reducing the use of reinforced concrete; maintaining the north-south orientation of buildings in order to reduce solar penetration into rooms; providing large roof overhangs again to reduce solar penetration and also to reduce maintenance costs; providing maximum cross-ventilation in order to maximise comfort; providing sloping ceilings again to maximise comfort and in the larger institutions using a structural grid for all buildings in order to standardise construction and provide a sense of order within the group of bildings.
In order to reduce construction costs in this project, the roof slopes were kept to a minimum in order to keep wall heights to a minimum. This was probably a false economy as the use of minimum roof slopes in countries such as Sierra Leone that have heavy rains inevitably leads to roof leaks and it is safer therefore to design roofs with steeper slopes that will quickly get rid of the rainwater.