A landscaped garden around a commercial building for people to sit back and relax is an excellent idea but very difficult to implement given that most properties have space constraints. Though the benefits of having live plants in the workplace are proven, many businesses simply don’t have the room for a breakout area that’s also outdoors. A rooftop garden is the best option for an outdoor green space in such buildings.
The trend is picking up in the commercial office segment with many companies located in the heart of a city transforming their rooftops into small gardens and ‘green’ spaces, allowing their employees to have a place to unwind and enjoy their lunch in the sun without having to leave the building. Being able to enjoy some time in the midst of nature has a huge array of benefits, and can even help to boost productivity at the workplace.
Structural considerations and approval
Before you start, here are a few important considerations to keep in mind.
Ensure you have safe and easy access to your rooftop, and that it has approval for pedestrian traffic.
The waterproof membrane needs to be completely intact and protected from your garden. Consult with a professional for the best advice before you begin work on your rooftop garden.
Consider the weather elements – wind, sun and rain – and see if you have to include any component in your design to block them out, making the space usable at all times.
Before beginning the project, have a structural engineer confirm the load capacity of the rooftop, especially its ability to hold garden beds and water tanks. Some rooftops are not designed to carry the amount of weight needed for a rooftop garden, so enlisting the expertise of a professional should be one of the very first items on your checklist.
Avoid a future leaky roof situation by ensuring the rooftop membrane is not damaged during the installation of the garden.
Secure the edges of the roof by installing railings. Do not place anything too close to the railing as this could pose a potential hazard. Find out from your local council what the regulations are in terms of the height a railing needs to be if you are installing them yourself.
Incorporate a water source for the rooftop garden during the design stage.
Complete all the formalities for council approval right at the beginning to avoid problems later.
Public safety issues are always a concern when it comes to public spaces, but your council should be able to inform you of everything you need to know about the requirements for a rooftop garden.
Cosmetic considerations
One of the most important aspects of a roof garden is the selection of plants. Choose plants that require minimal watering such as succulents – they are low maintenance, don’t need a lot of water, and enjoy lots of sun.
You also have an option of creating an edible garden on your roof. Growing veggies and herbs can be a welcome addition to any rooftop garden area, and something you should consider for the sheer satisfaction you’ll experience when you see the fresh produce.
If you are including a shade solution, think about how you can anchor the shade – perhaps a motorised or cantilevered umbrella or a few shade sails? This will all depend on how strong the wind is and how the sun hits your rooftop. Each space will have its own individual requirements, necessitating a customised solution.
When selecting outdoor seating and tables, ensure they can weather the elements and remain secured to your rooftop.
Add a few fun elements such as a giant chessboard or ping pong table, or even a barbecue if you have the space.
What if the rooftop has a limited load capacity?
If your rooftop is unable to withstand a complete garden, consider container gardens that don’t weigh a lot. When assessing the weight, always think of how heavy your soil will be at its wettest.
If there are issues with waterproofing on the rooftop, this can be easily remedied by having a professional come out and fix or change the waterproofing membrane so that it’s suitable for your rooftop garden.
Rooftop gardens are ideal for commercial buildings for so many reasons. Not only do they provide an excellent breakout area for those working in the building space, but they actually help to insulate the building and even control stormwater runoff. Rooftop gardens can also actually prolong the life of the roof’s waterproof membrane. Very importantly, a rooftop garden is the perfect way to add some greenery to your environment, even if it’s in the heart of a concrete jungle.
Projex Group is the Australian and New Zealand distributor for the Wolfin, Cosmofin and Koster ranges of waterproofing systems.
