Real People with Rooftop Gardens: Budapest Environs Support Green Roofs

Real People with Rooftop Gardens Series

A tribute to all of those who believe there is a right way to garden, both on a rooftop and on the ground. For gardeners, there is not enough soil to plant in, ever! Our site is reaching people all over the world and therefore we are so pleased to present an exemplary design and brilliant aesthetic from Douglas Gillis in Budapest, Hungary. Take me to Budapest, stat! I love this home and vista, wow!! We are all so lucky to get to know Douglas Gillis’ work through his story and photographs. Looking forward to many more Real People with Real Rooftop Gardens. Send us your submission to be featured by clicking here.

The roof garden has become part of a thriving culture targeted at improving the sustainability of our landscape and utilizing spaces in urban areas. While the focus of this type of development may seem to be directed more toward the commercial venture, it should be noted that there is a use for it in the residential market as well.

Here in Europe the development of the roof garden has an established history connecting it to mainstream architecture and garden design. The purpose of this article is simply to illustrate the perspective of one homeowner based on his observations and experience.

The house to be featured here was conceived by a Dutch architect, Erick van Eegarat. Built in 2003, it was a new style development within the Hungarian scene. There are 12 such houses on site, and each has a roof garden. The soil depth is 40 cm and the roof has been divided into three sections. There is no direct access to the roof garden, and so its function is architectural and ecological, rather than recreational.

Drains are located below the soil line in the lower corner of each section, and the concrete structure has been purpose built to withstand the weight. The greatest fear of roof gardens is the leaking roof, so it is the correct application of protective layers, as well as sealing around drains that is vital to its success. In this case, irrigation is minimal using drip line to keep the hardy shrubs going during the hot months. Given the Hungarian climate, irrigation needn’t begin until May or June, and can be discontinued in October.

Deciduous species have been used to provide shade, reducing the surface temperature considerably in summer. Six months later, they shed their leaves allowing the dark earth to absorb the sun’s rays at least until snowfall. This area provides a wonderful habitat for birds, lizards, and insects. These plants are also used as branches for Ikebana lessons, and so access by ladder for the occasional cutting is adequate. Although lavender has been used on the front corner as a showpiece, most shrubs are left to look wild and therefore blend into the surrounding hillside. Raspberries, blackberries, and rhubarb are also grown on the roof. All species can withstand minus 22 c in winter.

In 2007, the front area next to the drive was landscaped in 42 c heat. There is no window facing the south, but the atrium allows ample light into the house. If the house is sealed on hot days, the internal temperature on the upper level hits 26c at the hottest, while downstairs bedrooms are a constant 24c. Thus the soil on the roof acts as an insulator while the house, being partially submerged into the hillside, utilizes the hill itself as insulation. During early evening, the house can be opened and cooled within one hour using the forest air that moves through it without the aid of a fan or air conditioner. All in all, the roof garden cools the house in summer, and adds insulation in winter.

To date, the positive aspects of this project far outweigh the negative, and hopefully some of the ecological concerns that we feel today can be counterbalanced by technology and design as we see here.

By Douglas Gillis
Garden Designer and Historian
Budapest, Hungary