The roof garden designed by Tony Woods at John Lewis Oxford Street was my visit this week.
Tony was a RHS Young Designer. His team, Garden Club London specializes in roof gardens, urban gardens, living walls, and pop-up garden.
What do we need to learn to build a roof garden that is successful?
Weight is not everything…
When considering a rooftop terrace, the first question that comes to mind is “will it hold up the weight?”
Tony recommends that you consult an architect to determine the maximum weight your roof is capable of supporting. This doesn’t only include the pots, plants and soil, but also furniture.
People forget to take into account the weight of the people on the roof. The age of the John Lewis Garden means that only a few people are allowed to use the rooftop garden.
It’s important to note that this is not the only factor.
You can also get planning permission.
If you’ve got a strong flat roof and know that it is sturdy, you might assume you could put pots and chairs on top. Voila! Roof garden.
You will need to get planning approval for an actual roof garden. This may also include building control. How you will get to the garden is one of the things they’ll want to look at. You will have to go through a hatch. How will you prevent people from falling?
It’s also important to think about how you will get the materials for your roof-top garden up on top of the building. Tony says that John Lewis still had an “old carpet lift”, from when customers used to buy and take away their carpets right there in store. We had a lift that was three metres high. You’re limited to the height or length of the material you can take up the stairs, or use the lift unless you rent a crane.
The majority of people do not own a carpet elevator (carpet lift, in case you are reading this from the United States). Remember accessibility at the planning stage!
Consider the availability of water.
Roof gardens can be very hot. The plants in the pots need to be watered regularly.
Tony warns that watering is difficult if you have to climb a ladder or squeeze through a hatch while holding watering cans. It’s important to have a roof-mounted irrigation system or tap.
Consider your neighbors’ privacy
Your neighbours may find a roof garden to be a nuisance. Consider screens, and how you will view them.
John Lewis didn’t have many privacy issues because it is surrounded by offices and shops. They still needed screening. The neighbour on the left of them has an abandoned roof with air conditioners and other unsightly detritus. Tony says, ‘We planted a row amelanchier and hedges to block that view.
Tony designed the John Lewis rooftop garden in 2013. The London skyline is very different today. The London skyline has changed considerably since then.
Roof garden flooring…
Artificial turf might seem out of place if your goal is to be closer to nature. A real lawn would not be feasible. The decking and artificial turf will add insulation to your roof. They are therefore ‘greener than a flat roof’.
Millboard is the composite decking used on John Lewis’ roof garden. Tony says that wood decking does not always last. It gets slippery in the winter with algae and splintery during summer.
If you are concerned that a green area is environmentally-friendly, Millboard has had its carbon footprint independently verified. It is said to be about the cost of a latte.
Why have a rooftop garden?
Tony told me that he is most proud of the John Lewis rooftop terrace design.
I love the reactions of people when they step inside. The garden is an escape from the hustle and bustle of Oxford Street.
Roof gardens also have an environmental benefit, as they reduce the amount of heat that roofs emit. Planters and other plants help absorb the rain when it rains. This reduces runoff.
Tony says that the wildlife has enjoyed the garden. ‘We even had two ducks try to nest here to escape the crowds of Hyde Park’. The emphasis this year is on wildlife-friendly plants, natives and evokes an English countryside garden.