Alphen aan den Rijn: Ecolonia - the Dutch test case for sustainable town planning

Abstract:

The sustainable town planning project at Alphen aan den Rijn was commissioned by the Dutch national Environmental Agency in order to gain experience in the field of ecological town planning as well as in the area of ecological architecture. The project at Ecolonia is a remarkable achievement as it approaches the following areas of sustainability:

• emphasis on heterogeneity in urban planning and architecture in order to test different ecological approaches;
• rainwater utilisation;
• use of passive and active solar energy;
• implementation of energy saving concepts;
• reduction of water consumption;
• use of durable materials;
• design of flexible layouts;
• designing special soundproofing;
• special attention to the aspects of healthy living.

Concept and aims

In the mid-1980s the idea of the promotion of environmental awareness and energy saving building projects was given new impetus as the inter-disciplinary planning approach was being increasingly adopted in the field of ecological urban development. The intention of the Dutch demonstration project was to show the high quality of the knowledge already available. In consequence, the Netherlands Agency for Energy and the Environment (NOVEM) and the Ministry for Economic Affairs joined forces and commissioned a preliminary study on the feasibility of such a project in 1989. This initial step also included an inquiry with participants of the Ministry of Housing, Physical Planning and the Environment (VROM). The aim was to achieve a far-reaching consensus on the guidelines of environmental building and environmental conservation principles in order to identify the greatest possible basis for a sustainable estate.

After taking inventory of all the relevant guidelines, laws, national plans and political responsibilities, the involved ministries asked 17 architects to sketch out their ideas for an environmentally sound project in 1990. The aim was to construct a housing estate with approximately 100 dwellings. The architects had to concentrate on selected themes from the National Environmental Policy Plan. In 1989 the Dutch government published this plan in order to stimulate policies which would go beyond the statutory requirements of the policy field concerned. In the case of ecological urban planning, the national policy lines pay special attention to the areas of energy extensification, flow management, and quality improvement. The Dutch demonstration model implements these key principles by taking the following measures into account:

Energy extensification:

• the loss of heat should be reduced by the insulation of the individual houses, the installation of shutters (outdoors), and favourable positioning in relation to insulation;
• solar energy should be used through the incorporation of special garden rooms and sun lounges, as well as the particular zoning of room space;
• energy consumption should be reduced by a conscious building process and the energy consumption per residential unit was limited to a maximum of 300 MJ / m³ (low energy building materials, avoidance of energy-consuming construction methods).

Flow Management (Integral chain management):

• extra thought has to be given to the reduction of water consumption and the re-use of building materials (installation of flush toilets with minimal water usage, low-flow showers, apparatus with water-saving fixtures, selection of re-usable and renewable building materials, maximisation of the number of components that can be easily dismantled for re-use, installation of wooden floors between storeys as well as mineral wool in ceilings as a measure for noise insulation);
• special attention should be given to the use of ecological materials and the commitment to so- called organic architecture (careful selection of materials and components [e.g. cedarwood or European or Canadian hardwood instead of tropical woods], maximum use of granules from used concrete and brick, careful choice in the form and structure of spaces and building elements);
• the planning and implementation process should be open to flexible changes in construction and functions (creation of adaptable and easily extendible buildings, catering for combinations of living and working in the houses).

Quality improvement:

• one focus of quality improvement should be noise insulation inside and outside the house (especially soundproofing in facades and between rooms and installations, integration of a hanging system with rail of boards as fixed elements in order to avoid hindrance from drilling of holes in walls, provision of removable inner walls);
• health and safety should also receive special consideration (provision of open crawls in order to avoid radon gas, placing of smoke detectors in living and sleeping areas, use of fireproofed materials, extra fireproofed doors, fire escape routes with an attic window, placing of a straight staircase, entrance doors with safety glass, washing and drying facilities on the same floor, use of floor heating, avoidance of skirting-boards and wooden thresholds, installation of hanging kitchens and toilets, no dust collection corners);
• use of bio-ecological building principles and materials (avoidance of negative electromagnetic fields, use of non-toxic and water-soluble paints etc.).

In addition to theses guidelines the architects had to consider that the demonstration projects had to comply with the requirement of creating serialised buildings which are not limited to specific target groups but which will attract a wide range of buyers and will be affordable to most people. The architects involved had to design eight to eighteen buildings which integrated the above mentioned principles of sustainability. Finally, nine firms were selected to commission the final planning of the project.

Implementation

The 101 houses were constructed by nine architectural firms and, therefore, each group has its own ecological profile. However, in accordance with the construction guidelines the builders had to integrate certain themes of sustainability. The following ecological concepts have been put into practice:

1. Energy efficiency;
2. Minimisation of heat loss;
3. Solar energy use;
4. Organic architecture and durable materials;
5. Flexible construction;
6. Soundproofing;
7. Healthy building;
8. Bio-ecologically sound buildings;
9. Water consumption minimisation;
10. Traffic control;
11. Landscape concepts;
12. Social community concepts.

61 dwellings of the total of 101 buildings have heat-recovery controlled ventilation systems, 32 have mechanical ventilation without heat recovery, and the remaining eight dwellings are naturally ventilated. At nearly 80 dwellings solar collectors have been installed to the south. The east-west oriented buildings had not been equipped with solar collectors as the energy savings proved to be too low. Photovoltaics were rejected on financial grounds.

The minimisation of heat loss was the theme of a group of eighteen dwellings. Measures include wall construction of 120 mm thick limestone and a 130 mm thick solid thermal skin covered with 15 mm of plaster, the installation of blinds to provide shade in the summer, the equipping with particularly small windows to the north side and large ones to the south.

Ten dwellings in five twin houses were especially designed to experiment with the use of solar energy. These buildings use passive solar energy, as living areas are oriented towards the south and are fronted by a single-glazed conservatory for passive solar energy gains. All buildings are fitted with solar collectors for water-heating. Another group of eleven buildings incorporate passive and active solar energy use as they have additional solar collectors on the roof.

Organic architecture was the theme of another twelve houses. Ecological criteria like durability, maintenance level and embodied energy were all fundamental principles of their design. Cavity masonry of lime stone and burnt bricks were selected for massing. The roofs were covered with ceramic pantiles. European wood was used for the windows and untreated cedarwood was selected for other wooden parts.

Ten buildings demonstrate the advantages of flexible dwellings. Such houses have flexible external wall modules, changeable floor plans, moveable interior walls and variable installations. The inhabitants can alter both a room’s space as well as its function. An ensemble of staircase, supply shaft, and WC forms the core of the floor plan. The remaining rooms, including the kitchen, can be expanded or removed.

The ten buildings, which are designed by the Eindhoven Technical University, are test cases for soundproofing. The measures include low-noise heating and ventilation systems, the concentration of high noise-level rooms (kitchen, bathroom, stairwell, entrance) at the back of the building, noise protection in the remaining rooms by 150 mm limestone walls, and special construction of the bedroom (the quiet room) with an extra insulated timber frame and sound-deadening doors.

The twelve ”healthy buildings” pay tribute to the fact that health risks, such as allergies or psychological well-being, are increasingly becoming important factors of building design. The special design of these houses is characterised by sub-floor space heating, a vacuum system for the prevention of dust circulation, small landings on staircases etc. In addition, particular attention was given to the prevention of ”cold bridges”.

The area of bio-ecologically sound building saw the equipping of eight buildings with a solar collector for radiant heating walls which are developed in co-operation with industry. The problem of electromagnetic smog was dealt by with covering the floors with a 20 mm thick cork flooring and the painting of walls with natural paints. Furthermore, all these buildings have natural ventilation.

In order to disseminate the acquired know-how on sustainable methods of town planning, an information centre was established.

Actors and Structures

The client of the Ecolonia project was the Bouwfonds Woningbouw housing association. The urban planning procedure was executed by the Belgian architect Lucien Kroll from Brussels. The nine invited architects or architecture teams were BEAR-Architects from Gouda, Albert & Van Huut from Amsterdam, Hopman bv from Delft, J.P. Moehrlein from Groningen, Bakker, Boots, Van Haaren, and Van der Donk from Schagen, Lindeman c.s. from Cuijk, Peter van Gerwen from Amersfoot, Archi Service from Hertogenbosch and Vakgroep FAGO from the Eindhoven Technical University.

Finance

The Ecolonia project was co-financed by the Ministry of Economic Affairs and the Ministry of Housing, Physical Planning and Environment. The subsidies amounted 6 million Dutch guilders. An additional investment of 23,000 Dutch guilders per building had to be made. The cost per building varied between 180,000 and 300,000 Dutch guilders.

Evaluation and Statements

The Ecolonia project was run by the Bouwfond Woningbouw housing association, a private association which also has municipal representatives as members. Therefore, a close working relationship between the housing association, the municipal council, the architects, and other actors looked promising. However, the co-ordination process proved to be very time-consuming as departmental responsibilities had not been bundled up. Administrative insistence on sole responsibilities and inexperience in executing a sophisticated model project had to be overcome at a number of workshops and informative sessions. Nevertheless, this procedure led to difficulties in the planning and implementing process. In consequence, the funding approval process came under pressure and, therefore, a lowering of the ecological standards had to be accepted.

Source of Information

Ministry of Housing, Physical Planning and the Environment, (ed.) 1994: The Greenhouse Effect. Preventive Urban Actions in the Netherlands, Study by the International Institute for the Urban Environment, Delft, Den Haag

EA.UE, (ed.) 1994: New Sustainable Settlements in Europe. An Analysis of Experience of Seven Case Study Settlements, revised edition, Berlin

Personal contact with Roger Rovers, April 2000

Contact:

Cities:

Alphen aan den Rijn :

Ecolonia is a part of the town Alphen aan den Rijn, which is located in the Dutch ”green heart” between Amsterdam, The Hague, Rotterdam and Utrecht. This central location was an outstanding argument for accepting Alphen aan den Rijn as the small town which is best suited for a demonstration project in the field of ecological urban development. The site belonged to the city council and was originally marshland that lay below sea-level. Ten years before the projected started, the land had been artificially drained by pouring on a three-metre deep layer of sand. The only natural characteristic of the reclaimed land is the watercourse.

Population:

Project was added at 21.06.1996
Project was changed at 05.03.2001

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