Basics for green buildings

1. Planning of Green Roofs and Green Walls
Andras Bela Olah PhD
olah.andras.bela@gmail.com

2. Lecture 1: Introduction

3. Definition of green roof
Vegetation covered roof, where is a growing medium
under the vegetation and the plants and the growing
medium and the building composes one structural unit.
There can exist roofs, which are covered by vegetation without growing
medium (for example a roof covered by climbing plants).
There can exist roofs, which are covered by vegetation, the plants are
in growing medium, but they do not compose one stuctural unit
(container gardens).

4. Roof covered by climbing plants

5. Container rooftop garden

6. Historical facts about green roofs
The very first green roof was the Hanging Gardens of Babilon. There
were many of them, and not only in Babilon. There were among them
fake green roofs (without architectural spaces under them), but from
technological and sociological point of view those were also
emblematic (terraces of zikkurats, first aquaduct ever under the reign of
Sin-ahhe-eriba etc.).
Besides such emblematic historical examples like the Hanging Gardens
of Babilon and the sod roofs of Scandinavia the real green roofing
started only in the 1960ties, when the usage of waterproofing
membranes became common and widely used.
This green roofing movement started in Germany (West-Germany) and
even nowadays the german green roofing industry is considered to be
the best worldwide.

7. Different types of green roofs
There used to be mentioned two groups: extensive and
intensive green roofs.
The main difference between them is the maintenance and the
thickness of the growing medium. The extensive green roofs are not
permanently irrigated and have thin growing medium (15 cm or less
thickness). The intensive ones used to have thick „soil”, they are
permanenly irrigated and occasionally fertilized.
Sometimes a third category is also mentioned:
comprehensive green roofs.
These have the advantages of the two other types, i. e. weight and
maintenance of the extensive roofs and the quality of the intesive ones.
There is an other classification: pitched and flat green roofs.

8. Extensive green roofs
The extensive green roofs are not permanently irrigated and have thin
growing medium (15 cm or less thickness).
The main feature of them is the low maintenance: no permanent
irrigation, checking the roof only once or twice per a year, for cutting the
weeds.
The growing medium layer is very thin. This is very advantageous on
the one hand, because the building structure does not have to bear
extra strain. Thus, extensive green roofs can be widely applicated onto
existing buildings.
Because of the thin „soil” layer, the material of it and the plants must be
special. The plant types also determined by the local climate.
The main plant species used to be Sedum and mosses.

9. Extensive green roofs
Sod roofs are vernacular in the scandinavian region. Because of its
simplicity, low maintenance and the special local climate (high relative
air humidity and high rate of precipitation in every season) these can be
considered as an extensive green roof.

10. Extensive green roofs
Extensive green roofs in Chicago (City Hall) and Stuttgart (green roof
landscape). The rate of precipitation and the relative air humidity are
significantly greater than in Budapest. These are so called Sedum-moss
roofs. Among drier circumstances the Sedum becomes dominant.

11. Extensive green roofs
Extensive green roofs in Budapest. The so called „Buffalo House” in the
Budapest Zoo and the rooftop of the Antenna Hungaria office building
(pics by Dr. László Gerzson). These are basically Sedum roofs due to
the arid climate.

12. Intensive green roofs
The intensive green roofs are permanently irrigated and have thick
growing medium (at least 15 cm, but rather more thicker 40-50 cm, or in
case of planting greater trees 80-100 cm is common). Permanent
fertilisation is also common.
This type has more disadvantage, but its few advantages are
unequivocal.
There can not be simply establish an intensive green roof on an existing
building due to structural requirements.
The whole building structure must be stonger, which highly increases
the price of the whole building process. The mainenance cost is also
much higher.
Despite, this is a viable way to establish a new green area, which
effects are similar to ordinary parks and gardens. These roofs can be
used as real gardens.

13. Intensive green roofs
The very first intensive green roof. The Hanging Gardens of Babylon.
Established in ancient Mesopotamia. Waterproofing (natural bitumen
and lead layers) and irrigating (canal system, Archimedes’ screws with
more than 400 years before Archimedes ) was necessary.

14. Intensive green roofs
An intensive green roof with the maintenance of an extensive one.
Irrigation is determined by the local climate. In Singapore and in all
rainforest zones the permanent irrigation is unnecessary.

15. Intensive green roofs
Intensive green roof on the top and on the side of the Vancouver Public
Library. The maintenance level is also low in temperate rainforest zone.

16. Intensive green roofs in Hungary
Westend City Center in Budapest. Intensive green roof over a shopping
mall and a railway station (pics by Dr. László Gerzson)

17. Intensive green roofs in Hungary
Westend City Center in Budapest. Intensive green roof over a shopping
mall and a railway station.

18. Intensive green roofs in Hungary
Westend City Center in Budapest. Intensive green roof over a shopping
mall and a railway station.

19. Intensive green roofs in Hungary
Westend City Center in Budapest. Intensive green roof over a shopping
mall and a railway station.

20. Different types of green walls
There exist real green walls, where the wall itself contains also the
growing medium and simply vegetation covered walls, mostly covered
by climbing plants. A more simple solution is a special allee close to the
facade of the given building.
The real green walls can be further separated into two subgroups:
indoor green walls and outdoor green walls. Both of them is considered
to be intensive, because they need continuous irrigating. That is why
they can not be considered sustainable, excepting the case of the
usage of greywater by residental buildings.
The outdoor green walls has an other problem due to the necessity of
continuous irrigating: they can not be considered frost proof.

21. Different types of green walls
Spalier, a not so widely known method for creating a green wall. Usually
made from pear or apple trees.

22. Different types of green walls
Deciduous climbing plant (boston ivy/Parthenocissus) covered buildings.

23. Different types of green walls
Evergreen climbing plant (creeper ivy/Hedera) covered buildings.

24. Different types of green walls
Outdoor green wall/vertical garden in Madrid (CaixaForum Madrid).
Invented by Patrick Blanc.

25. Different types of green walls
Indoor green wall/vertical garden in Budapest (Avis Green House office
building, pic by Green Fortune).

26. Thank you for your attention!