Green Roof and its advatages

Since the previous post brought up the green roof, I thought it would be appropriate to develop and explain a little bit more about the green roofing system and all its advantages. 

A green roof is a living surface of plants growing in a soil layer on top of the roof. It is constructed of many different layer on top of each other, to both protect the roof and to give a nurturing layer of soil for the plants to grow on. See here in the diagram how it could be built up:


There is 2 different basic versions of a green roof:
- Extensive on based on a very thin layer of soil which mean not alot of plants can grow here but it also means that very little maintenance is necessary.
- Intensive on the other hand has a much thicker layer of soil and can look like an ordinary garden, with trees and many different plants. But just like a garden, it needs more maintenance. This version can also only be constructed on a roof that can bear the heavy load.

This way of using vegetation on the roofs are, as you might know, not a modern invention. This a long traditional way of building in many places. But this green roofs you see in modern buildings today are very different from the traditional ones seen in the country side. This is mainly due to the different purposes and materials available nowadays. The main objective in the traditional green roofing was to use the turf as insulation and also to stop the waterproofing layer (which was mostly birch bark) from blowing away. Today the objectives are mainly environmental, economical and to improve storm water management, health and aesthetics in the community.

Advantages of Green Roofs:
Energy and economy

Cooling effects - a normal black roof can easily reach temperatures of up to80 degrees Celsius in the summer. When a soil layer and the shading plants protect the roof, the surface temperature usually doesn't rise above the surrounding air temperature.
- plants and soil evaporate water, creating a cooling effect and a moister air

Insulation and reduced wind chill
- in the winter the soil layer provides additional insulation, especially the intensive version of green roofs.

Life expectancy of the roof membrane
- The green rood protects the waterproofing layer on the roof from both the uv-light and the temperature extremes, increasing the life expectancy of the membrane from about 25 years to at least 60 years. So we save materials, energy and money and produce less waste, by using less then half of the amount of roofing materials.

Solar energy- there is no need to choose one or the other, there seems to be a postive effect both on the efficiency of the photovoltaics and on the biodiversity when roof vegitation and solar panels share the same roof. Bio diversity benefits from the patches of shade and sun provided by the panels, creating a mosaic of different mricoclimates. The photovoltaics, on the other hand, seem to benefit from the lower surrounding temperetures over the vegetation, as opposed to the normal black roof.

Storm water

Green roofs - One of the most important effects of green roofs in the cities is their potential for retaining and delaying rainwater during storms. The gutters and sewers in the city have to be big enough to cope with the amounts of water that falls during extreme storm events. As more and more surfaces in the built up areas are made hard and impermeable, less water can percolate naturally into the soil. This means that the sewers and treatment plants get higher and higher loads.
On average, an extensive green roof of 5 cm thickness, has been shown to take up 50% of the annual rainfall and evaporate it to the air.

Health and the Environment

The Heat Island Effect - the heat island effect, which makes the average temperature higher than in the country side, is becoming a big problem for peoples health and also an economic issue. All the concrete and stone and asphalt in a city absorbers the heat during day time and releases the heat during the night. The warm air also rise over the city, so that cooler air is being sucked in from the outer areas towards the center. Unfortunately, the outer areas of a city is usually filled with motorways and industrial areas, which means that the cooler air getting sucked in is very polluted.
The green roof can help to avoid this problem, with stopping the hard surfaces from absorbing so much heat by shade and also by transpire moisture into the air, which helps to cool the air down. All plants added to the city will help to improve the local climate.

Noise - the constant traffic noise echo against everything hard, like buildings and paved surfaces which leads to the noise echoing back and forth and never getting absorbed. A soft surface, like a green roof or a vertical garden mutes the noise instead of reflecting it back and forth.

Dust, pollution and the increased greenhouse effect -  dust particles, including heavy metals and other pollutants that circulate in the air to some extent get trapped in the green roofs and stays there in the substrate rather than disturbing our respiration or getting washed into the ground water.
The biggest global climate issue of our time is the increased greenhouse effect. This is the global warming that is caused by carbon dioxide (CO2) and some other gasses, such as ozone (O3), that when they reach the upper layers of the atmosphere traps the heat from the sun, keeping the earth warm. Human activities have in the past 150 years or so increased the amount of CO2 in the atmosphere, with negative effects on our entire global climate.
Green roof vegetation, as well as other vegetations, use CO2 for their respiration, and therefore reduce the negative effects of pollution. This is not a method that can be used as an only solution to the problems of pollution and global warming, but together with all the other beneficial effects of green roofs, it is a small step in the right direction.

- a green roof are also to a great importance to the animal life in the cities. The green roofs can contribute to a greater biodiversity and habitats like ruderal land can quiet easily be replicated on roofs together with its often endangered invertebrates as well as some bird life. 

angered invertebrates as well as some bird life.

School of Art, Design and Media in Singapore

The School of Art, Design and Media in Singapore is a great example of a contemporary building which is not only sustainable but also eco sensitive and flows into its surroundings. With an high tec internal with facilities such as Stop Motion Studio, 3-D Hi-End Computer Graphics Studio, Soundstage, Sound Recording Studios, Audio Visual Editing Suites, Hi-End Digital Post Studio etc it should only be right to be as high tec and up to date externally. But it is not only high tec that matters, the basics are just as important. The internal shows concrete walls and colums, cement-sand screeded floors, timber railings and a natural palette, which also has to be proved all the way to the external walls.

This high performance building with its curved glass facade is oriented north and south to reduce the solar gain and heat load. The curved building allows the courtyard to seduce the glass facade with features of reflection though water and plants, which gives a distinct feeling of endlessness. But the most noticeable green instrument in this beautifully worked out building is the turfed roof that blends into the lush greenery and the surroundings. Not only does this lovely landscaped roof give a scenic external communal space, but the green roof lowers both the roof temperature and ambient temperature hence reduces the heat gain to the air conditioned building.

There is also an integrated water collection system fitted on the green roof for irrigation. The rain sensors are installed on the green roof to automate the irrigation process whereby irrigation is ceased when it rains.
This gives a sense of the ultimate combination; whilst high tec and innovation is a must for sustainable thinking, going back to the basics are just as important for a sustainable future.



Sustainable design; so much more then Eco Design

Sustainable design embraces the main interdependent and indivisible areas of environmental protection, economic development and social development:

environmental protection – Ecosystem intgrity, carrying capacity, biodervsity
Includes redusing waste, effluent generations, emissions to envirnoment, reduse the impact on human health, increase the use of renewable raw materials and elimination of the toxic substances.
Sub-theme: Global, Local and site, Internal
Issues: Climate change, resources, internal environmanet, external environment, wildlife

economic development – Growth, deveopment, productivity
Includes creation of new markets and opportunities for sales growth, cost reducation through efficiency improvmentas and reduced energy and raw material inputs and creation of additinoal added value.
Sub-theme: Construction, materials, infrasturcture
Issues: Profitability, employment, productivity, transport and utilities, bulding stock value.

social development – Cultural identity, empowerment, accessibility, stability, equity
Includes wrokers health and safety, the impact on local sommunities, quality of life and benefits to disadvantaged groups.
Sub-theme: Equit, community
Issues: Poverty, minorities, inner cities, transport, communications

This is exactlly what I wanna talk about in "talk about eco stuff" .


Some Background: The Hannover Principles

The Hannover Principles


The concept of sustainability has been introduced to combine concern for the well-being of the planet with continued growth and human development. Though there is much debate as to what the word actually suggests, we can put forth the definition offered by the World Commission on Environment and Development: "Meeting the needs of the present without compromising the ability of future
generations to meet their own needs."In its original context, this definition was stated solely from the human point of view. In order to embrace the idea of a global ecology with intrinsic value, the meaning must be expanded to allow a l l
parts of nature to meet their own needs now and in the future.
The Hannover Principles aim to provide a platform upon which designers can consider how to adapt their work toward sustainable ends. Designers include all those who change the environment with the inspiration of human creativity. Design implies the conception and realization of human needs and desires.

Design for Sustainability:
Designing for sustainability requires awareness of the full short and long-term consequences of any transformation of the environment. Sustainable design is the conception and realization of environmentally sensitive and responsible expression as a part of the evolving matrix of nature.

1. Insist on rights of humanity and nature to co-exist

2. Recognize interdependence. natural world, with broad and diverse implications at every scale. Expand design considerations to recognizing even distant effects.

3. Respect relationships between spirit and matter. including community, dwelling, industry and trade in terms of existing and evolving connections between spiritual and material consciousness.

4. Accept responsibility for the consequences of design of natural systems and their right to co-exist.

5. Create safe objects of long-term value maintenance or vigilant administration of potential danger due to the careless creation of products, processes or standards.

6. Eliminate the concept of waste. to approach the state of natural systems, in which there is no waste.

7. Rely on natural energy flows. forces from perpetual solar income. Incorporate this energy efficiently and safely for responsible use.

8. Understand the limitations of design problems. Those who create and plan should practice humility in the face of nature. Treat nature as a model and mentor, not as an inconvenience to be evaded or controlled.

9. Seek constant improvement by the sharing of knowledge. between colleagues, patrons, manufacturers and users to link long term sustainable considerations with ethical responsibility, and re-establish the integral relationship between natural processes and human activity.

The Hannover Principles should be seen as a living document committed to the transformation and growth in the understanding of our interdependence with nature, so that they may adapt as our knowledge of the world evolves.