Kenya's home style is changing. When it comes to new construction, traditional houses with pitch and iron sheet or tile roofs have given way over the last few years to sleek homes with flat roofs. The rooftop terrace is all the rage.
Once a preserve for coastal areas, flat-roofed homes are fast gaining traction across Kenya. Even in rural areas, new homeowners are building flat-roofed homes.
From Kitengela, Juja, Kamakis, Kangundo Road, Syokimau, Ruiru and Waiyaki Way, hundreds of flat-roofed homes pepper the landscape.
Eco-Build Offices in Kitengela, Architect Alfred Omenya is the owner and founder of Eco-Build Offices.
Photo credit: Dennis Onsongo | Nation Media Group
Prof Alfred Omenya, an architect, says that flat-roofed homes have been in Nairobi, even since the 1940s, but now they are sparking interest among young people.
“If you look at Nairobi West, there were a lot of flat roofs in the 1940s and 1950s. Flat-roofed homes date back to the 1920s. We started seeing them disappearing as people were not able to put up good quality buildings, which resulted in leaking.
This made flat-roofed homes very expensive to maintain and we saw more people opting for pitched-roofed homes. Many homeowners also opted to convert their flat roofs into pitch roofs.
Then we started seeing a resurgence of flat-roofed homes globally in the 1990s, all the way to the present day,” the founder of Eco Build Africa explains.
Why the uptake?
Prof Omenya attributes the comeback to the fact that current homeowners are well-travelled and more exposed and want to replicate the designs they have seen abroad even in their rural homes.
Founder of Eco-Build Africa Architect Alfred Omenya during an interview on July 31st, 2024, at his office in Kilimani Nairobi.
Photo credit: Billy Ogada | Nation Media Group
It is a design opportunity, for the homeowners to “float the house off the land,” meaning the views from the rooftop terrace are better and entertaining is done at the rooftop.
“Many people building now are more travelled and know more about the global trends when it comes to architectural aesthetics. I have noticed the uptake of flat- roofed homes both in practice and at the academy.
I have many students designing flat-roofed buildings. In practice, we have also seen many clients requesting flat-roofed buildings,” the professor who teaches at the University of Canberra and Kenyatta University tells the Business Daily.
"Many of my older clients still go for pitch-roofed homes but the younger ones almost all of them want flat roofs as they consider pitch-roofed homes to be more traditional."
Waterproofing products
Better quality materials and new technology have made the flat roofs modern and possible.
According to Prof Omenya, one key factor causing the recovery of flat-roofed homes is “the availability of waterproofing products in the market.
Buyers can trust that today’s architects and builders can make a flat roof that does not leak.
"We've started seeing firms coming up with more reliable products as well as warranties. They come and say to you, ‘we shall do the waterproofing of your roof, and we shall give you a warranty of either 20 or 40 years,” Prof Omenya says.
This has built the confidence of aspiring homeowners.
Advantages
Do they have advantages, or it is just a trend?
With flat-roofed homes home, owners have more space. Jeremy Kireru, the sales director at AAD Real Estate, says, “Clients majorly consider the functionality.
Land is becoming scarcer so people are looking to build flat-roofed buildings to have more space for people to relax or have a restaurant. If it is a stand-alone house, you have more space to even do your gardening.”
Some homeowners are turning the rooftop terraces into extra rooms, perhaps a prayer room or office. Others have setup an entertaining/relaxing area complete with a kitchen, toilet and grilling area.
Mr Kireru says that the majority of the homes that the property developer is working on are flat-roofed.
Sheila Mwaragu, a structural engineer, adds that in apartment blocks, the flat roof space can be used for swimming pools as there is no shade and also saves ground space in tight sites.
Another advantage is the environmental perspective.
Prof Omenya says metal roofs gain and lose heat faster than concrete.
“If you do a metallic roof in hot places like Kajiado, Mombasa or Kisumu, you end up with big temperature swings in your building. The metal roof will heat up quickly and lose heat quickly leaving you with an uncomfortable house.
“On the other hand, concrete has a time lag, heating up slowly and also holding heat much longer so during the day, your concrete house roof will be cooler and during the night, it will be warmer,” he explains.
Cost
Is it cheaper than pitched-roofed homes?
Even with the cost of repairs being removed due to the availability of quality waterproofing products, flat-roofed homes are still costlier to build compared to pitch-roofed units.
“Flat-roofed is basically reinforced concrete and the cost of cement and steel has gone up disproportionately compared to the cost of timber and metal roof covering. That means when building a flat roof, you spend a lot more,” Prof Omenya says.
Some homeowners are turning the rooftop terraces into extra rooms, perhaps a prayer room or office. Others have setup an entertaining/relaxing area complete with a kitchen, toilet and grilling area.
Photo credit: Shutterstock
He adds, “If you just like the aesthetics but don’t have the money, you can do a flat-looking roof and do a low metal roof on it.
“That is, you create a parapet around the building and then put a very shallow metal roof so people will see it as a flat roof. There is absolutely nothing wrong with a metal peached roof.”
Disadvantage
Prof Omenya says that the biggest challenge with flat roofs arises when they are poorly done.
“Not many contractors know how to design a flat roof properly. You must design it well and have waterproofing done properly; otherwise, you will find leakages. Good design for flat roofs also incorporates drainage.
“Lay the concrete to slope and do proper concrete gutters to deal with the vast amounts of rain; otherwise, you will end up with a situation where the gutter fills up and keeps dripping."
Ms Mwaragu says that the roofing choice depends on the homeowner's preference.
“One thing to note for flat roofs is that they have shallower gradients as compared to pitched roofs. This necessitates proper rainwater drainage and waterproofing.
“Such roofs need to be adequately waterproofed through the addition of waterproofing admixtures into the concrete mix during concrete works. There are various products in the market.
“Other ways of waterproofing your flat roof include applying waterproofing materials to the concrete slab and designing a thicker concrete slab with a higher concrete grade. It is good to provide sufficient falls/slopes on the slab for drainage of rainwater.”
Prof Omenya who has constructed a flat-roofed office in Kitengela says, "The way I design my buildings is I consider the spirit of the place. When doing my rural home, I looked at how people built there traditionally, so I kept a pitch-roofed home.
“I wanted a slightly different approach for the more urban one as this is a more modern place,” he says, adding, “flat roofs are not just for mansionettes. Now, we are doing a lot of flat roofs on bungalows, too.”
