Looking after the grass

How much green space there has to be for each residential project is governed by the current regulations, but for many developers these are just the starting point. On their own initiative they are adding greenery to walls and roofs as well as providing rain gardens and allotments

Biologically active surface (which according to zoning plans has to make up a minimum of 25 pct of each residential project) can be provided in a number of ways, so it’s always a good idea to bring in a greenery designer in the project’s initial stages. “The lead designer responsible for the estate’s design concept doesn’t have to know anything about botany or ecological services,” points out Monika Szewczyk, a biologist specialising in biodiversity preservation at the UN Environmental Programme/Global Research Information Database (UNEP/GRID) centre in Warsaw. “Working together with a landscape architect or greenery designer from the outset of a project increases the chances that the approach adopted will address a greater number of environmental issues. Then, with around the same amount of effort and money, something can be achieved that will eventually be hugely beneficial for both the eventual residents and in terms of maintaining urban biodiversity,” she insists.

Planting seeds for the future

Ensuring that cities have areas is a way of ensuring our own well-being, although we often don’t fully appreciate this. “We continue to look at greenery – such as can be found on residential estates – mainly from an aesthetic point of view. We plant whatever looks nice and is fashionable or whatever’s cheap. But with all the talk about the climate crisis, we are slowly coming to realise that green areas play an important functional role. We are beginning to appreciate the effect they have on the urban microclimate and on rainwater retention. One test of how functional they are could be whether, for example, a resident of an estate, such as a mother with a small child, is able to walk down the street shaded by trees rather than in the full glare of the sun,” argues Monika Szewczyk.

The inclusion of vegetation – and this doesn’t necessarily have to be trees – reduces the air temperature during heat waves, and this could, in turn, reduce the air conditioning costs for the interiors of buildings and apartments in estates. Plants can also help to bring down heating costs. For example, in one of Equilis Europe’s recent developments in Warsaw’s Białołęka district, carefully selected wall creepers act as an additional layer of insulation for the building and protect the apartments from both summer overheating and from the cold in the winter. Green roofs can also provide a similar insulating function.

First keep what you have

Residential estates are usually built in places where plants already grow. The existing vegetation can then be integrated into the project itself and even determine the shape of the concept. Such was the case with one of Cordia’s developments in Poznań on the site of the former Modena clothing factory, where old trees grew that were covered by a conservation order. “The entire project was designed around an alley of plane trees, which in our concept forms the main axis of the estate. A dendrologist was brought in to help us look after the trees. We pruned them and removed their dead branches. They were also protected from the construction work, with great care taken not only of their bark but also their roots. In the documents we submitted to the conservator, we designated the zones where no equipment or building materials were to be allowed that could have harmed them,” explains Joanna Kasperczyk, a project director at Cordia in Poznań. The company also hired a landscape architect and consulted local residents about the project as well as a number of nature specialists. “We listened to a number of opinions and implemented many of them. For example, we increased the green roof area and decided to change the species we planted,” adds Joanna Kasperczyk.

Gardens above your head

The green roofs that are to be created on Cordia’s estate can be seen in many other projects under development today. “For the first of these, there is to be an extensive zone with plants as well as an insulation zone with solar panels. We’ve managed to fit it all in,” reveals Joanna Kasperczyk. Developers are often keen to use green roofs when there is little other space for plants. “In densely built-up areas, we put more greenery on the buildings in our projects. And not just on car park buildings, but also in the form of green roofs,” points out Radosław Beneda, the project development director at Euro Styl. Due to its less extensive nature (with shorter plants and shallower roots), only half of the roof counts as biologically active surface, but it still plays a significant role in the urban ecosystem. “Green roofs increase biodiversity and reduce the amount of water that goes down the drains,” explains Jacek Zengteler, the vice-president of Yareal Polska – a developer that has also embraced this approach with its projects.

Water, water, everywhere

Polish cities are generally becoming hotter and dryer, apart from those days when there are downpours. “Environmental organisations are generally concerned about retaining as much rainwater as possible in a given area. With Cordia’s Poznań project, there are a number of features that support this, including green roofs and the use of rainwater for watering plants. In the designs for the future stages of our Poznań project, we want to include basins that retain even more water,” emphasises Joanna Kasperczyk.

In the TriCity area, Euro Styl has been including rain gardens in its projects for several years. “Such a garden requires the species being planted to be able to remove the impurities from the rainwater that flows off the hardened surfaces and roofs,” explains Radosław Beneda. As he goes on to say, you also need to use plants that can cope with occasional flooding: “The right choice of species will work in a rainwater garden by absorbing the excess water and gradually consuming what is retained,” he adds.

The cost of going green

The costs for creating a green area represent just a fraction of the entire project, although the final outlay depends on the scope of the work and the approach taken by the developer. “We estimate that the average cost required for providing a green area together with the topsoil, planting and outdoor furniture will at the most come to 5 pct of the total construction costs,” asserts Jacek Zengteler. “However, this does not give us an accurate picture of the full costs of developing a green estate. The largest portion of these costs – and this can be difficult to measure – is for determining the actual construction area. The buildings need to be positioned in a way to give room for green enclaves or whole strips of greenery (so-called linear parks, including areas designated for native species and the planting of well-developed root-balls. For this it is crucial to carry out a scrupulous analysis and assessment of the existing trees and to adjust the layout of the estate for existing plants,” insists the vice-president of Yareal.

Developers have to take on board not only the financial outlay for creating green areas but also their future maintenance. “We try to ensure that our greenery’s upkeep is as easy as possible and that it is as best suited as possible to the particular site - then it has a chance to look as good or even better in five- or ten-years’ time,” claims Radosław Beneda. Yareal is also aware of such long-term benefits. “Our design work requires the planting of native species that don’t require excessive watering or special care,” explains Jacek Zengteler.

Rain gardens, which play a key role in the retention of the water on the grounds of an estate, are, unfortunately, not cheap. “The costs for creating them are much higher than for standard greenery. You have to carefully select the topsoil layer as well as additional overflow systems. Some of our projects have rain gardens that have been working well for years. We have gained quite a lot of experience in this area, and certain approaches have been improved upon to make the gardens easier to maintain and care for. The amount of work required is, however, always greater than for standard greenspace. Basins need to be cleared of leaves and from time-to-time the plants need to be changed and refreshed,” admits Radosław Beneda of Euro Styl.

Certified green

Green certification requires specific measurable activities for green areas. Skanska, Bouygues Immobilier Polska, Vastint Poland and Yareal all use international standards In Poland, while Echo Investment has introduced its own standard, while not long ago the Polish Green Council introduced its own Zielony Dom (Green Dwelling) standard.

“From the earliest stage involved in choosing the materials required for certification, a plan is drawn up to manage the landscape that includes guidelines for the construction stage and the function of the project,” reveals Jacek Zengteler. “Before the construction work begins, plants that require protection during the construction work are documented. The management plan lays out how the natural areas are to be treated as well as new environmentally valuable habitats, as well as the care for the planned sites in response to changes and their future care. All the environmental aspects of the project are set out in the ecologist’s report,” he insists.

The living environment

The greenery of an estate is so much more than the cherry on the cake of a project or just some bothersome necessity that needs to be dealt with at minimum cost and effort. Flower meadows, rain gardens, green walls, linear parks and even allotments that residents can take care of themselves are all examples of a creative and long-term approach to environmental issues and complying with increasingly strict ESG guidelines.