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Thursday, June 6, 2013

Urban Sustainable Development - The case of Hammarby Sjöstad in Sweden

Today’s post discusses about the role of urban planning on sustainable development and shows us the interesting case of a district in Stockholm area that halved its overall environmental impact!

For the first time in history, urban areas have more population than rural ones. Today, around 52% of world’s population is concentrated in metropolitan areas (Word Bank, 2011) and this number continues to rise. The recent growth of cities has demanded more from urban planners who have to come up with new strategies in order to guide developments in the right direction.

View of Hammarby Sjöstad 
In the early 1990’s, with the attempt to host the Olympic Games, Stockholm decided to change the old industrial and harbor district around the Hammarby lake (“Hammarby Sjö” in Swedish) into an innovative residential area. Today, the “Hammarby Model” has become an example of city development around the world. When completed in 2015, it will house more than 25000 people in around 11000 apartments.

The project aimed to reduce the total environmental impact by a half compared to ordinary Swedish households. In order to comply with this goal, improvements and modern solutions were put into place concerning a number of environmental issues. With its modern and sustainable design, the project completely transformed completely the cycles of water, energy and waste in the area as we can see below.

Energy

The main idea was to make the residents to produce 50% of the energy needed. Solar cells capture the sun’s luminous energy and convert it into electrical power in solar cells. Some have been installed on several facades and roofs providing the energy needed for their public areas. In addition, solar panels have been installed on the roof of the buildings.  These panels capture the warm rays of the sun and use them to heat the buildings hot water supply. By converting domestic waste and wastewater into heating, cooling and electricity, the district decreased the imports of energy. In addition, the use of more efficient and eco-friendly building materials and domestic appliances contributed to decrease the total energy consumption.

Water and Sewage

The goal was to decrease by a half the consumption of water compared to the Swedish average. This was done by the use of eco-friendly installations as washing machines and dishwashers, low flush toilets and air mixers on taps and showers reducing, thus, the volumes used. The district have its own wastewater treatment plant that uses new cleaning technologies. There, organic materials are separated from wastewater and carried to digestion tanks where biogas is produced. The gas is used as fuel to public transport and stoves and the remaining biosolids are used as fertilizers. Rainwater from yards and (green) roofs is drained into the lake instead of going to wastewater treatment plant and rainwater from streets is treated locally using settling basins and then drained into the lake.

Waste

The waste is separated in proper containers and recycled, re-used or discarded according to its nature. Combustible waste as paper and plastic (non-packaging) are sent to the incineration plant where it is transformed in heating and electricity for the community. Food waste is composted and converted into biogas and fertilizers. Other types of waste are recycled and in the last case sent to landfills. The collection system consists of underground pipes under vacuum suction (this system was already explained in a previous post, click here for a more detailed explanation) which reduces CO2 emissions, air and visual pollution.

The diagram below shows the integrated approach of the project showing waste, water and energy flows.
Other beneficial modifications in the region were made regarding land usage and transportation. The area was transformed from a contaminated industrial spot into an attractive residential district with parks and green public spaces. The soil was fully decontaminated in order to ensure that no one is exposed to any risks in conjunction with service work in the future. Existing vegetation has also been saved.



The district has fast and effective public transportation (especially by tramways), combined with carpool system and beautiful cycle paths. The area is very well connected to center Stockholm which makes it even more attractive! It also counts with pathways along the canals, sports and cultural centers as well as pre and elementary schools for children.

Today, Hammarby Sjöstad receives thousands of visitors per year including mayors from all over the world and other public administrators in search of this successful case of sustainable urban development. The model has already been exported overseas to Russia, China and UK.

The question that remains now is if it would be possible to expand this model to other countries. Unfortunately, those sustainable urban models are mostly seen in wealthy countries. The developing economies are most concerned about first developing their territories economically and secondarily with the creation of environmental programs. On the other hand, what we do see today, even in emerging countries is the green building industry that raises attention and start to warm up market! One thing is certain, independently of the wellness of the nation, engineers and urban planners have still a long way to go and a lot of work to be done!

On your next visit to Stockholm, take some time and go to visit and explore this incredible place with difficult name!