Sanlam Tower, a state of the art eighteen storey office tower designed by GAPP Architects & Urban Designers, is setting new standards for high rise building construction in Kenya.
According to Peter J. Muller, who oversaw the construction on behalf of GAPP Architects & Urban Designers, the building draws upon lessons learned on previous projects to create a timeless design that will appeal to many generations while remaining appropriate to its life cycle. “It was designed to be constructed quickly and within the allocated budget, but keeping in mind its functionality and durability after completion.”
Located along Waiyaki Way in Nairobi, the tower is envisaged to grow Sanlam’s global brand presence within Kenya. “The building hosts an eighteen storey office tower with a lettable area of 15,000 square meters, a four storey basement parking, as well as a three storey above-ground parking silo. The building is designed to have standby generators for backup power supply and a borehole to supplement water supply,” said Muller.
A number of energy efficient and green architecture systems were central to the tower design:
With environment conservation in mind, the design uses a 13mm thick clear laminated double tempered performance glass instead of traditional air conditioning. “The thermal performance glass reflects heat while allowing light into the building, reducing glare in the process. Moreover, the glass allows heat to build up and absorbs heat from the roof,” explained Mr. Muller. The choice of the ideal combination of solar factor and U-value is essential in cutting down the building’s energy requirements, as well as saving on investments in cooling systems and maintenance.
Sanitary & Water Saving
A number of innovative sanitary ware fittings were incorporated into the building. The design initially proposed the use of waterless urinals. Unlike regular urinals that utilize fresh water to flush the system, this waterless system uses gravity to flush the waste instead. “The outflow pipes connect to the building’s conventional plumbing system. In other words, unlike a composting toilet which leaves you to deal with your waste, the urinals send the waste directly to a water treatment plant,” says Muller. “This type of urinal system is cost-effective since no fresh water pipes are needed, with no mechanical or electric parts and no additional water required. It is also more hygienic, considering there is no flushing mechanism and is odourless, saving on the need for air fresheners and perfumed tablets,” he added.
Due to cost constraints, the waterless urinal system was not implemented. An automated flush urinal, linked to a user sensor was however installed instead. While still incorporating fresh water flush pipes, the system uses less water than regular urinals and can be adjusted to optimize water usage.
In addition, the building is also the first in Kenya to utilize a Hygizone system. Accordingly to Muller, “The system involves extracting the foul air directly from the toilet, removing odour and bacteria from the source before it contaminates the washroom. This extraction from the toilet bowl provides a reduction in the airflow required, and is more efficient than conventional systems. When you utilize the Hygizone, you eliminate the age old problem of toilet odours and airborne bacteria.”
“Unlike the common extraction systems that draw odours out of the toilet bowl and into the air we breathe, the Hygizone does the opposite. It draws odours inwards, preventing it from leaving the toilet bowl altogether. The system connects to the duct in the ceiling, and expels it outside.” explains Muller.
Natural cross ventilation
Natural cross ventilation, Muller explains, involves supplying and removing air from an indoor space without the use of mechanical systems. This type of passive design attempts to use the natural air pressure and forces to pull air through the building, and is the least expensive form of cooling and ventilation from both a financial and environmental point of view. Successful cross ventilation is determined by having high levels of thermal comfort and adequate fresh air for the habitable spaces, while having limited or no energy being supplied for active HVAC cooling and ventilation.
According to Muller, the building has a dual window system that will aid in influencing air flow. “In order to maximize wind ventilation, you want the pressure difference between the inlet and outlet to be maximized. In most cases, high pressures occur on the inlet side of a building and low pressures occur on the outlet side. The approach is more convenient since it helps prevent excess moisture and heat from building up in the ceiling. If you want cooler air, opening the bottom window will allow the warmer air will rise and ventilate the room,” demonstrates Muller.
The design for Sanlam Tower placed a strong emphasis on the use on natural lighting which is supplemented by artificial lighting when required. According to Muller, “The building uses occupation sensors during the day to enhance natural lighting. This goes a long way in energy conservation.”
The eastern and western façade, which are more vulnerable to peak morning and afternoon sun, are protected with aluminium fins to reduce solar glare and heat gain, as well as serving to enhance the aesthetics of the building. The design also incorporates a “light tower” on top of the building, which Muller explains will form a visible landmark and signage structure that will be visible from a distance. The tower also hides the water storage tanks on the roof.
With the ongoing threat of global terrorism in Kenya, the security design had a significant impact on shaping the building. According to Muller, these concerns were carefully considered and taken in account, particularly in terms of accessibility and the physical nature of the building.
The Sanlam Tower has placed significant emphasis on fire detection and suppression mechanisms to ensure the highest level of fire safety when the building is in use. “We contracted one of the best Engineering firms to evaluate the fire requirements and make recommendations on the best possible approach to fire detection and suppression within the building. These mechanisms are to meet the highest of international standards,” said Muller. “This includes fire lobbies, fail safe sprinkler systems and fire breaks within windows, which ensures the vision glazing system breaks in the event of a fire,” he added.
Water has been a major challenge in the city over the years. With this in mind, the building is designed to harvest and store rain water collect from the roof. “Considering the small size of the roof, we decided to do piping in order to have enough water,” says Muller. “In addition, we have included other systems for water conservation, such as the use of infrared sensor sanitary fittings which are designed to operate directly from a main water supply. The sensor operates on detection of a user by infrared beam,” he added.
Multiple elements within the design are subtly used to create a unique synergy between classical proportions and modern forms within the tower façade. The aluminium shading fins, while reducing solar glare and heat gain, enhance the vertical proportions and aesthetics of the building. At night, these fins along the eastern and western façades will be illuminated to create a glowing effect, emphasizing the vertical lines and patterns, while the light tower on top of the structure forms a glowing crown that can be seen from a distance.
The main entrance to the building is accessed via a large roundabout with a unique water feature at its centre, characterized by a series of large granite cubes. A central atrium around the reception area stretches four storeys high, creating a grand entrance and sense of generous space within the building.
The building includes a series of landscaped and terraced spaces, providing break areas for users. The rooftop will include a multipurpose terrace and function venue that can be used for corporate events, and is divided into an indoor area with air conditioning facilities, as well as an external area for public functions. Additionally, artificial plants are used on the terraces to minimize water consumption.
As seen on Construction Review Online