Garden on the roof

If you are planning a house and you find that the space left for a garden is a little limited, the rooftop can make for valuable space upon which you can create a beautiful green haven for you and your family.

In so doing, you will also be doing great service to the city and the environment by reducing storm water runoff, replacing the greenery lost by your building’s footprint and adding much-needed greenery to the urban fabric.

Needless to say, roof gardens also add great aesthetic and green credentials to your home or building. Here are a few tips to help you plan or retro-fit a roof garden.

The roof

Roof gardens are best incorporated at the design stage of the building. This way, all functional and structural considerations are taken into account and addressed right from inception.

Many buildings with a flattish section of the roof can be modified to accommodate a roof garden.

However, it is strongly recommended that you seek professional advice before you do anything that was not originally in the plan. Ask a structural engineer to assess your roof and ascertain that it is strong enough to support your plans.

A roof garden at Morningside Office Suites, Ngong Road, Nairobi. The rooftop can make for valuable space upon which you can create a beautiful green haven for you and your family. (PHOTO: COURTESY)

Also make sure the roof is sufficiently waterproofed and drainage is sorted. Otherwise, you will end up with a wet ceiling in the long-run.

There are many effective and long-lasting water-proofing solutions in the market today. Again, to be sure, ask a professional to recommend the most effective water-proofing and drainage solution for you and insist on a guarantee.

Lastly, don’t forget to provide an easy means of accessing the rooftop. It is needless to have a beautiful roof garden, which you have to access via a ladder. See if your staircase can extend all the way to the roof or create access through the attic or a new staircase on the side of the house.


For roof gardens, a bold and simple design is always a winner. Most garden concepts that can be executed on the ground can be adapted to the rooftop, albeit in a small way.

A common practice is to extend the interior design concepts outdoors so that the roof garden feels like a natural extension of the indoors.

Containers should be selected in line with desired look and feel. Long lightweight containers are preferable as they put less strain on the roof’s structure and they distribute the weight more evenly. Lightweight tiles of a restful colour or timber decking can also be considered for flooring as long as they tie up with the rest of the furniture and decor.

An overhead structure for shade can be a worthy addition. Pull-out canvas awnings or a simple lightweight pergola can define the perfect outdoor living room and provide a much-needed respite from the hot sun.


Conditions on rooftops can be very different from those on the ground. Special care should therefore be taken in order to select plants that will not only enhance your design concepts but also survive hot and windy conditions.

The sun and shade patterns are particularly important. Assess the orientation of the roof vis-a’-vis any elements in the neighbourhood that cast shadows such as trees and buildings.

This assessment will help you to determine where to put each plant in terms of their shade or heat tolerance.

Many drought-tolerant plants will survive on the roof. Visit your local nursery and find out which ones are available.

Acclimatise the young plants to their new home by first planting them on the ground in an area that is fairly exposed to the afternoon sun. That way, they will be less-strained when you eventually transplant them to the roof.