The need for energy conservation, in these days of scarcity of resources, cannot be gainsaid. Ironically though, many architects, designers and developers do not give proper consideration to energy efficiency during design of the buildings. The buildings orientation, massing and finishing are usually dictated by factors such as land, its formation and structure and the aesthetic requirements of the client.
However, all is not lost as a middle ground can always be achieved, one which balances the site and client demanding requirements against the need to conserve energy.
This feat has been achieved with high levels of success at the Strathmore Business School. The school was awarded the Best Green Building Development in Africa by the African Real Estate and Housing Finance (AREHF) academy awards in March 2012. The awards were designed to appreciate those who have put in measurable efforts in boosting the real estate and housing finance market in the African region.
The client wanted a building for the purpose of serving an overwhelming need for world-class executive training in Africa. The building was required to have ultra modern facilities and have the capacity to accommodate up to 800 executives.
The building has four storeys and a basement. The internal partitions in classrooms are flexible and can adapt depending on the teaching style and need to ensure that the students get the maximum out of their lecturer and each other in discussion rooms and breakout areas.
The building features a dramatic Atrium. This is known as the soul of the building as everything revolves around this space. It is multidimensional as it can be used as an auditorium, graduation court or cinema.
It has 12 tiered, breakout areas, each of which can seat 10 people on break-out mode & up to 20 on auditorium mode and circulation spine. It features two giant waterfalls and a tensile structured glass roof curtain wall system.
The building also features an auditorium, chapel, dining area with a lounge and a spill-out balcony, library completely fitted with indoor air quality designed to meet LEED standards with optimum relative air changes controlled using evaporative cooling air units situated at the top of the building.
Construction of MSB
The MSB lay out and foundations were constructed using well shaped stone with no exterior finish. Curtain-walling was carried out using 12mm clear glass. The windows are aluminium framed fitted with 6mm clear glass. The entire floor is of porcelain and ceramic tiles while the interior is of cement and plaster finish.
The MSB covers 4,570 square metres and has four storeys and a basement. The main building mass is oriented in the North-South direction presenting minimal direct solar radiation onto the building façade.
The windows are made of aluminium frame and 6mm clear glass panels. They are set into the wall to provide further shading by the walls and roof overhang. Integration of day lighting into the building has been achieved through use of 12mm clear glass curtain walling system.
The Western façade of the building is shaded by a neighbouring building while the Eastern side has roof overhangs and set in windows which permit minimal solar radiation into the building.
Another feature of the building is extensive use of natural ventilation through windows which can be opened. The roof is a slab structure with a coating of polyethene and tar, with a polished aluminium top foil finish to maximize the reflectivity of solar radiation and thus minimize heat gain on the slab.
The main source of energy is electricity from the national grid. The building is also supplied by a stand by generator for emergency loads in case of mains power cuts.
The building has Building Management Systems integrated into it to control the resource utilization. User defined control-programming was used to define the functioning of the various components such as motion detectors, power cards and lighting control.
Lighting control system is directly affected by the building envelope designs. The system uses room orientation and time of day to disable lighting fixtures that are close to the windows when sufficient natural lighting is available. It also disables all lighting in individual rooms when the motion detectors indicate that the area has been vacated.
Use of energy efficient fluorescent tube lighting with electronic ballast adds to the host of other energy saving measures employed in the design.
Rainwater from the building roof is harvested into underground water storage tanks where it is treated before being pumped to the various water taps in the building. An estimated 90% of water needs for the building are met using the harvested rain water.
Provisions have been made for evaporative cooling ducting in the whole building. The systems have however only been deployed at the basement due to the sufficient natural ventilation and high indoor air quality in the other spaces in the building.