BuGG-Market Report on Building Greening 2021

BuGG Market Report on Building
Greening 2021


Building greening market
The building greening market is growing continuously – this can be said primarily for green roofs and also, to a certain extent for facade greening. Reliable figures are available for both, even if the recording methods for green facades are not fully developed yet. Although
the year 2020 was marked by the Corona pandemic, around 7,800,000 m² of roof area was newly greened in Germany in 2020 – 600,000 m² more than in the previous year. It corresponds to a growth of 7.2 %. The increase from 2018 to 2019 was 4.2 %.
Even though significantly more green roofs were built in 2020 than in 2019, the proportion of green roofs on new flat roofs remained the same – at around 8 %.
In addition, about 55,000 m² of facade surfaces were developed in 2020 as ground-bound facade greening with climbing aids (approx. 45,000 m²) or as wall-bound facade greening (approx. 10,000 m²). The current figures are more “reliable” than the values from 2019, as
it was possible to make greater use of manufacturer information this time.
There is no method for presenting figures about the different types of interior greening in square metres yet. The development of methods for this is a task for the next few years.

Green Roof National League
There are no changes at the top of the BuGG Green Roof National League, although Hamburg has joined.
Munich is leading in the category of green roof area (excluding underground car parks) with 3,148,043 m².
Stuttgart is on top in the category of green roof index (square metres of green roof per inhabitant) with 4.1. The average green roof index is 1.3 – still a slight increase compared with the pre vious year.

Welfare effects of green roofs in figures
In Germany, the total amount of greened roof areas over the years is about 130.000.000 m². With an assumed extensive form of greening this means for the various welfare effects:
– a water storage capacity of about 3,90 0,000 m³
– an evaporation capacity of about 260,000 m³ per (summer) day
– an annual precipitation water retention of about 56,940,000 m³
– a CO₂ storage of about 1 04,000 t
– a fine dust storage of about 1,30 0 t.
The performance of intensive greenings are significantly higher.

Municipal subsidy instruments
Green roofs and facades are more and more accepted as an important adaptation measure to climate change: rainwater management (flood protection), heat prevention (evaporative cooling), species protection/biodiversity and health prevention. More and more cities are implementing this knowledge into their municipal subsidy instruments, as shown by the current city survey and additional rese arches of the BuGG – 42 % or rather 34 % of the cities with more than 50,000 inhabitants promote green roofs and facades and provide financial subsidies. In 2019 it was only 25%
for green roofs and 24% for facade greening. The development and increase of the number of cities is therefore worthy of note! It can be traced back in large part to the funding support and initiative of the
state of North Rhine-Westphalia. According to BuGG findings, 106 cities nationwide (from 20,000 inhabitants or more) provide subsidies for green roofs and 81 cities grant su bsidies for green facades.
77 % of the cities with more than 50,000 inhabitants promote green roofs indirectly and reduce the rainwater charge for the presence of green roofs. This is a small development compared to the previous year (72%), but we are already at a high level in this area.


Your own roof garden – it has never been as valuable
as it is today!

Additional usable and recreational areas for people – the in-house roof garden are a crisis-proof leisure, recreation, and cultivation area. If we consider the figures from 2008 to 2020, the trend is moving clearly in the direction of “intensive greening” (roof garden).
Whereas in 2008 only 11.4 % of the green roofs were
intensively greened, this figure has increased to 17.9 %
in 2020.

Greening in existing buildings
Many cities promote green roofs and facades in existing structures, in order to literally disarm “Hot Spots” and to use the cooling capacity of the greenery in a targeted manner. In many cases it cannot be realized due to the building statics, or only to a limited extent.
Innovative solutions (e.g. lightweight construction with/without irrigation) are in demand and provide product and system manufacturers possibilities for further application areas.

Conflicting goals of photovoltaics and greening
Due to the emerging solar obligation of many federal states, a conflict of objectives “solar” vs “green roofs” seems to arise. Here it is necessary to broaden and communicate the knowledge and the possibilities of “solar green roofs” more widely. Solar green roofs combine climate protection and climate change adaptation
and serve, among other things, flood pre vention!

For various reasons, the trends of the last few years have strengthened, and they are already more than just “trends” – retention green roofs, biodiversity green roofs and urban farming roofs are quite well known by cities as well as by planners. They are increasingly demanded, well supported, and implemented. Newly
added are aspects of preventive health (Planetary Health), which are being promoted through the many welfare effects of green roofs and facades.

Research and Teaching
The basics of building greening have been explored, but now we need to get into the details and ask specific questions. More precise data is requesting, for example characteristics of plants and systems in order to be able to calculate and simulate the effects of greening.
It is important to anchor the teaching at universities of architecture, urban planning, etc. firmly with the topic of building greening in their curricula.

Barriers and obstacles
In its comprehensive survey, the BuGG asked various target groups to find out why green roofs and facades have not been implemented more yet. It turned out that the concerns about production and maintenance costs, damages to the building and a lack of (specialist)
knowledge are obstacles and barriers.
One of the most important tasks of the BuGG is to educate cities and planners on the basics of greening buildings as well as their properties and effects. The BuGG therefore offers various formats and a comprehensive range of further training courses (including
“BuGG-certified consultant for green roofs and facades”).
The BuGG attempts in cooperation with other associations, organisations and cities to organise a “Green Building Action Week” in autumn 2020. Within one week, information on green roofs, facades and interiors are imparted in the form of nationwide seminars, lectures, inspections, greening shows, photo competitions, etc.

The full report can be found here.