Lideta Mercato - More than just a pretty face
The facade of Lideta Mercato – an eight-storey shopping mall in central Addis Ababa, Ethiopia, which is due for completion at the end of June – is it’s most striking feature, but its green building attributes run much deeper.
The facade is arguably Lideta Mercato’s most compelling aspect and the reflection of a desire in lead architect Xavier Vilalta of Vilalta Architects to “make the building attractive for people”. Its patterns are based on traditional African fractal designs, found commonly on women’s dresses, which serve as decoration and for natural ventilation.
Built with lightweight concrete, the perforated facade regulates temperature and sunlight, while also anchoring the building in its local context. “I wanted to find something that people from the street without any architectural knowledge would relate to,” says Vilalta. “When you do something in a specific place you should find features that somehow belong to that place and use them.”
Using local inspiration went further than just the design of the mall – it meant looking at the surrounding business environment and incorporating that into its function as well. In this case, the structure, function and design of Addis Ababa’s largest and busiest open-air market, the nearby Mercato, provided a guide on how the mall would look, feel and function.
“They commissioned a market study to check what would be the capacity if the vendors in the market were offered a new building – with the same kind of shops but in a more contemporary way,” says Vilalta. “That showed the buying capacity of these businessmen was higher than the big commercial brands that would go into a conventional shopping mall.”
The design of the mall hinges on small stall-like shops and an open-air feel facilitated by a design that enables passive ventilation. From the beginning, Lideta Mercato broke the rules of conventional shopping malls, while incorporating key principles of green building. This meant doing away with preconceived notions of what a shopping mall should look like.
To change the paradigm, Vilalta had to sell the concept as good business – and he had to have an open-minded developer. These were two things that he managed from the outset.
“There was no reservation to construct the building from the very beginning,” says Biruk Shimelis Atlaw, deputy general manager for development at Flintstone Engineering. “It was a perfect project in line with our vision to deliver green, affordable and state of the art properties in all business areas as a real estate developer.”
The initial market surveys have been telling; within the first three months of going on the market 60% of the business space was sold to vendors. Now, mall space is sold out.
Air and Light
After wandering through glass-sided buildings in Addis Ababa and noticing that most people stick paper on the windows in order to blot out the bright Ethiopian sun, Vilalta realised Ethiopians preferred dim light opposed to bright light – he learnt this in particular while visiting vernacular Ethiopian architecture examples at Lalibela. This informed the fractal design, and allowed him to achieve a facade that protected the interior from too much light.
“The concept is very simple,” he says. “The building is on a north-south position, which creates a flow of air, and there is an open-air situation, as you would have on a balcony but protected from the sun and rain.”
The north-south aspect combines with an internal corridor, and a void that runs diagonally from top to bottom, through which an inclined elevator to the roof passes. The inclined atrium area also creates its own diffuse light patterns. From the ground floor, the light refracts into the space in different colours, so looking up, there is a rainbow effect.
Solar energy and water
Ethiopia’s biggest challenge is the constantly interrupted power supply, a situation that is offset most commonly by costly and carbon-heavy fuel generators. But Ethiopia’s climate lends itself to solar energy – and Vilalta and his design team, with the agreement of Flintstone Engineering, capitalised on this by designing circular shaped solar umbrellas for the rooftop space. These also provided shade in a space that in effect became an outdoor patio.
“Because it’s a commercial building, the majority of electricity is required during the day, so the combined 98kW is enough to cover the main facilities – the elevators, escalators and lights,” he says. For this reason, the solar system works in a closed system, and is self-consuming.
“The first reaction to the solar panels was that they were too expensive,” says Vilalta. “But then we spoke about energy stability. You have to have a huge generator to produce 98kW.”
The outdoor roof patio also facilitates rainwater collection. A drainage system gathers rainwater through pipes in the umbrellas and in other areas on the roof. The water is then drained, stored in a 170m3 tank in the basement, and filtered through the building to the toilets and taps. When there is not enough rain to fill the tank, water from the utility is used.
Telling the story
It is interesting to note that the biggest selling point of the building is the rooftop patio and solar energy. “The marketing material shows the building always from the top, because they want to show the solar energy,” says Vilalta. “It is interesting how the building itself has become an object of desire.”
There isn’t a green building rating system in Ethiopia yet – and Vilalta says the sustainability of the building is purely practical and economical. “It’s not about going for a trend,” he says. “There are a lot of smart solutions that have come out of necessity. The main target should be solving problems. And the best rating is when people like it.
“People have said: ‘you come from Spain but you have designed something so Ethiopian’, and that you can see on the faces of people when they look at the design. That for me is very important.”
By Karen Jayes
The full feature appears in the June/July 2015 issue of earthworks magazine.