There are pros and cons to a rooftop oasis; namely you make great use of otherwise wasted space, get great sun exposure, and you don’t have to worry about deer and rabbits. But there are a few hoops to jump through.
Is the building engineered to hold the weight of a garden? This is your main limiting factor. The combination of soil, water, and vegetation is heavier than you may think. If you’re not sure, a contractor or architect can help you figure it out. Your roof is likely able to safely take a certain amount of weight, and it’s good to know where that limit is.
- An intensive green roof will likely weigh around 23 or 34kg (50-75lbs) per square foot, depending on type of soil used and the depth.
- Raised beds weight will likely weigh around 16kg per square foot (35lbs).
- An extensive green roof is usually between 6 and 9kg per square foot (13-20lbs).
Check the “rooftop garden designs” tab for more information on these different designs.
Do you need city permits? Contact the local government and if appropriate check with your landlord and/or the building code. There may be height restrictions, fire regulations, or other things to be aware of.
Once you’ve got the boring part out of the way, It’s time to start brainstorming. Make a map sketching out your garden plot, preferably with measurements, showing where the garden beds and any furniture will go. This will help you estimate how many materials you will need. Take some time to observe the sun and wind exposure your roof gets- this will inform what kind of plants to grow and where to place them on the roof.