Multiple use of space in railway station areas

Transcription

1 Multiple use of space in railway station areas Th.S. de Wilde Holland Railconsu[t and Universip of Technology, The Netherlands Abstract Rural areas near cities are getting more and more affected by the demands for space from ourever-growing population. Multiple use of space within city limits can diminish these demands and simultaneously contribute to a sustainable city centre, Obviously, it is quite a task to design and construct projects with multiple use of space in urban areas. However, in spite of many difficulties, there are already projects that have been realised. These projects aremostly located inexpensive city districts and some of them are partly built above railway infrastructure. Railway stations and railway yards form obvious locations for such projects, because of their central position in a city s transport network. The paper sets out why railway stations and their direct surroundings are preferable to other inner city locations for these projects and it focuses on opportunities and challenges of multiple use of space as an instrument to add to a sustainable city. To illustrate the practical possibilities of multiple use of space near railways in urban areas, three largescale reference projects are discussed. 1 Introduction Cities expand. Social demands fclr more space, with high expectations for its quality, are rapidly affecting the rural areas outside cities. Because of the resulting significant consequences for our environment, the building within city limits has become governmental policy By making more intensive use of certain occupied spaces in cities, one can meet the demands for more space and one can safeguard the rural environment at the same time. In this respect, multiple use of space is an interesting option to create the demanded building space within urban areas.

2 530 m.s7i.y[cli/lt7bi? City [1 2 Multiple use of space Multiple use of space combines different functions. In urban areas this will lead to individual projects with a combination of office, residential, and retail fimctions. The presence of more than one function is the essential condition for multiple use of space. When analysing such projects, it is important to choose the right scale. On a high scale every city or city district has more than one function. Multiple use of space can be subdivided into three types with combinations being possible. multipleuse of space Figure 1: Different forms of multiple use of space 2.1 Mixed use of space In a project of mixed space use or mixed use development [1], different functions are combined within a limited surface. Multiple use of space always implies mixed use of space, because by definition different functions are included. Mixed use of space is quite common in cities where different fimctions were combined within the city walls, A typical example of mixed use of space is the Stopera in Amsterdam. The Stopera has been realised in 1986 on the site of a former inner city district, This complex combines the Amsterdam city hall and a music theatre. 2.2 Multiple use of land A further developed form of mixed use of space is multiple use of land. In multiple use of land each different fimction is placed on top of the other using the land more than once. It must be able to operate the fimctions independently, but the synergy between them forms an important success factor, Multiple use of

3 land can be realised above or underneath the intlastructure of railways and motorways, but also above existing buildings. Examples of multiple use of land above infi-astructure are found in The Hague and in Rijswijk In The Hague, five buildings have been constructed above the local motorway, the Utrechtsebaan. The first of these buildings to be realised was the <Haagse Poort, In Rijswijk, an office building and a residential building have been constructed over the railway between The Hague and Rotterdam Figures 2 and 3: The Haagse Poort over the Utrechtse Baan in The Hague and an office building over four railway tracks in Rijswijk. 2.3 Multiple use in time A building can be used for different functions at different moments, This form of multiple use of space is multiple use in time, Multiple use in time has, hotvever, limited applicability for regular urban functions, An example is found near Bijlmer Station in Amsterdam. During the day the Pathe theatre is used for conferences and in the e~enings for mo~ies. OffIce workers in the surroundings can use the car parking facilities under the square at daytime and visitors of the theatre can use the car parking facilities in the evenings, 2.4 Advantages Multiple use of space has social benefits, Redevelopment of inner city areas can locally lead to an improved urban fabric and to a better social climate, This will also lead to a certain extent to sustainability for these locations, and, of course, to the environmental effect of saving the rural areas outside cities, as mentioned above. The challenges in the multiple use of space are set out in section 6, 3 Intensive use of space Apart from combining different ftmctions with multiple use of space, it is also important to use the area intensively. The required surface area of a building site can be smaller, if one builds more intensively, and, consequently, fewer building sites have to be looked for, It is, however, hard to determine whether the surface

4 area is used intensively or not. The perception of the extent of intensity depends on personal opinion and is thus subjective. It is also partly determined by culture, In multiple use of space, the presence of more than one fimction can be determined objectively. In reference projects discussed in this paper as well as in most other example projects, multiple use of space and intensive use of space are both applied. 4 Suitable locations Multiple use of space will demand extra investments due to auxiliary structures and the fact that construction will preferably take place in urban surroundings. Suitable locations can be found in areas where the expected profits of new real estate will justify these higher investments. The most expensive areas are generally found in city centres, so it is there that we will find the obvious locations for the application of multiple use of space. The largest building sites within city centres are near infi-astructure, and especially near infrastructure of railways. Many railway stations were built at the city boundaries between 1850 and 1900, but today these stations ofien have a central position, occupying large and expensive surfaces of railway tracks. The space above these railway tracks is an excellent location to construct a second surface area on which buildings can be realised. 5 Opportunities for railway station areas Railway stations in cities are easy to reach for most people, They are also near all the amenities that the often historic city centre has to offer. They are the centres of public transport networks and have connections with all forms of local transport. Multiple land use on these locations has a positive side effect: the social benefit of stimulating public transport as an alternative for the more polluting car. The railway station area often has a high intrinsic ground value. The intrinsic ground value of inner city surface areas with railway tracks can only be turned into money by enabling construction of buildings on top or underneath. City districts on both sides can be connected when building over the infrastructure, which will increase the value of the surroundings. The improvement of the local urban fabric is also a value-adding element, because the railway view is exchanged for real estate. 6 Challenges in the multiple use of space Realisation of multiple use of space is subject to multiple challenges in different disciplines. At Delft University of Technology, a congress has been organised in 2001 to map the challenges of building near and above railways in urban areas [2], These challenges were subdivided into four different categories: engineering, safety, finance and organisation.

5 6.1 Engineering The Smtctimble City [1.533 Constructing buildings above railway tracks is difficult, The infrastructure of railways is a complex system and train services must be maintained during the construction phase. It is therefore recommendable to consider the possibilities of realising buildings next to the railway tracks first, In the design process it is important to bear in mind that special measures must be taken for building physics, This includes measures for noise, vibrations, electromagnetic compatibility, air quality and daylight on the railway platforms. Problems with building noise in the construction phase need extra consideration, because construction will mostly take place during the night when the railway Wdcks are used less intensively, Low noise building methods are required as well as a reduction of building time [3]. Smmt solutions combine the co&truction of the buildings with work on the railway tracks, Figure 4: Different possibilities to integrate the structures of infrastructure, the second surface area and real estate The structures should have a grid system that anticipates on fhture changes, The buildings that will be constructed have an economic life cycle of about forty years, while the infrastructure of railways is designed for more than a hundred years [4]. Three structural solutions for infrastructure, the second surface area and real estate are given in figure 4. Both the flexibility of the railway system for future changes and the possibilities of changing the buiklings above it will decrease when these fimctions are built on top of each other. SO, when designing and constructing such projects, one should keep in mind that these new developments will form the environment of the work and lives of many people in the decades to come and one should not cut down on the quality. 6.2 Safety The safety has to be maintained in both the construction phase and the exploitation phase. In the construction phase, attention must be paid to the techniques that are used for the construction and to the size of the structural elements that can possibly fall down. In the exploitation phase special attention must be paid to fire safety and extra precautions must be taken to protect the structure in case of colliding trains When multiple use of land results in a

6 railway tunnel underneath the new buildings, specific rules and regulations of tunnel engineering, for instance for escape routes, should be applied. A specific safety problem is the transport of dangerous goods on the section where multiple use of space is planned, Transport of chlorine and LPG is for instance very common in the Netherlands. This form of transport in itself is already an existing safety problem in densely populated inner city areas. Specific safety measures are needed when new real estate is also planned above these sections. The extra measures are needed both to minimise the risk of a disaster and to control a disaster when it occurs 6.3 Finance Building above railways is expensive. The extra costs should, however, not be attributed only to the real estate developers, because realisation of multiple use of space has also important social benefits. To earn back the extra costs of real estate above railways a combination of a high rental income per square meter and a large amount of floor area are needed. A high rental income per square meter alone is not enough, because price and volume together make up the total revenues. When projects are larger, phasing becomes an important additional factor. The possibilities to market the developed floor area depend on the fluctuation of the real estate market and other real estate developments in the region, Another aspect that influences the feasibility of the project is landownership in the project area. When designing a masterplan, land positions must be taken in consideration in order to align the different parties, When land positions are well considered it is easier to determine how profits on the project will be divided in a later stage. Furthermore, there is the matter of pre-investments that have to be made in the infrastructure. It must be considered to take these in hand first, in order to prevent that trains must be taken out of service during the construction of real estate If real estate is realised much later, the interest costs of these preinvestments will run up, so it is important to minimise them, To reduce building time it is recommendable to consider investing in foundations that allow prefab structures of future buildings above. 6.4 Organisation Redevelopment of inner city areas involves a great number of parties, each with their own interests. It takes a lot of effort to bring these parties together, especially where legal and financial affairs on landownership and air-rights are concerned. The government can act as a catalyst in this process by initiating and facilitating the projects, After all, multiple use of space in inner city areas has social benefits and helps towards the preservation of green belts and rural areas. Especially in high risk urban environment, developers could be persuaded that the risks are worth to be taken, if the government provides subsidies for the gap between the costs and the profits of a redevelopment project [5].

7 Another possibility is that the government shares in the benefits or losses of these projects. They can add force to their policy of stimulating multiple use of space by taking a part of the risk themselves. 7 Reference projects Some projects of railway location redevelopment combined with multiple use of land have already been realised. Three large-scale reference projects in different countries with a comparable scale are described below. Each is in a diflkrent stage of the project: exploitation (Broadgate, London), under conduction (Rive Gauche, Paris), and in development (Zuidas, Amsterdam), 7.1 Broadgate, London Liverpool Street Station and its direct surroundings were redeveloped between 1985 and The project consists of 360,000 mz of floor area on a surface area of only 100,000 mz [6]. About a thkd of the floor area of the project is realised above the railway tracks. The rest is placed beside the railway tracks. Most of the real estate above the railway tracks is located over the platform area Only the Exchange House is placed over the railway sidings near the end of the platforms, spanning almost 80 meters. Figure 5: Redevelopment of Liverpool Street Station and its surroundings In the redevelopment of Broadgate, a lot of attention has been paid on phasing. The first phases of the project were realised beside the railway station. The profits of these first phases were then used to finance tie later phases. Together with the right marketing of the offices, it was the most important success factor of the redevelopment. The project mainly consists of offices, so it is ahnost mono-functional in its use, apart fic~mthe railway function.

8 536 w.%taiuab[e ( it, II 7.2 Rive Gauche, Paris Rive Gauche is an inner city project on the left bank of the Seine that will be under construction until 2005 [7]. The project has a surface area of about 1,300,000 mz, on which almost two million square meters of floor area is planned. In this project, different functions are mixed, and in this respect it differs from Broadgate. The project has offices, residential complexes, public services, and retail, but the offices still form the main part. The large amount of public fimctions indicates that there is a close involvement of the local government. One of president Mitterand s Grand Projets, the National Library of France, was already opened in 1996 as the first part of the project. Figure 6: The development of Seine Rive Gauche is under construction 7.3 Zuidas, Amsterdam The Amsterdam Zuidas is a project of the same scale as Seine Rive Gauche. The project is set up with the goal to become the second city centre of Amsterdam with all the amenities that are needed to make an animated district. The project plan consists of more than two million square meters of floor area, which are divided into equal parts for offices and housing [8]. By developing a large number of houses next to the ofllces, the public spaces will also be in use outside business hours and the station will be used more efficiently, for passengers will use the station in both directions during rush hour, The existing infrastructure will be expanded and is planned underground, The most expensive part of the operation will be to bring the infrastructure underground and to integrate the infrastructure with fiture real estate above, The

9 VIP Slistainuble City II.53 7 new ~ound level that is created will be ilat, so consequently there will be a good connection between the city districts on both sides of the infrastructure. Developing the Zuidas is planned to take up about twenty to thirty years. ~~,,, Figure 7: Perspective cm the Zuidas development plans 7.4 Indices on land use The reference projects can be analysed on building volume and on their use of space. The floor space index (f.s,i,), or floor area ratio (f.a. r,), can be used to do so. It measures the ratio between the floor area that is realised and the surface area it uses: i.e. the intensity of the use of space. Table 1 shows that Broadgate has been built much more intensively than Rive Gauche or the Zuidas. The difference can be ascribed to the size of the surface area and local cultural differences, When the surface is larger, more open space is needed and this will make the intensity lower, Another intensi~ing factor is the depth of the office buildings in Broadgate, which is up to 40 meters, This depth is not allowed in Continental Europe. The floor area ratios of Rive Gauche and Zuidas are quite comparable. Table 1: Building volumes and densities of the reference projects [6,7,8] Broadgate Rive Gauche Zuidas Qj@s (nlj 330, ,000 1,007,000 Residential (n+) o 550, ,000 Shops and catering (m2) 30, ,000 Public services (m2) o 250, ,000 Tblal ( /) 360,000 1,920,000 2,252,000 h urfacc(m2) 100,000 1,300,000 1,720,000 Floor.Ypiu index Functional division Apart from the density of the develctpment, there is a difference in the division of functions. The Broadgate development has ahnost only office buildings. It is defined as multiple use of land because the office buildings have partly been built over railways. The projects Rive Gauche and Zuidas on the other hand, plan a large volume of residential buildings next to the offices. These new districts

10 will have a more animated ambience than Broadgate, especially in the weekends. Planning a combination of offices and houses can be considered as a trend to create a sustainable and lively city. In spite of the lower profit than office development would, housing is well integrated in the projects. This is a direct result of governmental involvement, which reduces the mere pursuit of gain and adds to the quality of life in these projects. 8 Conclusion It is clear that multiple use of space can contribute to the preservation of rural areas out side cities by applying it onto extensively used urban areas such as railway yards. Although realisation of multiple use of space is difficult and expensive, there are already examples of how to intensi@ land use near railway stations in urban areas. In the design stage, taking landownership into account will add both to the feasibility of the project and in aligning the different parties. The government will play an important role in facilitating the initiative and, in a later stage, in regulating the design process and looking after a consistent mix of ofllces, residential complexes and other urban fimctions. When thinking of the growing need for more space and the greater awareness of spatial quality that is present in our society today, it is obvious that the parties working on the projects as discussed above are doing pioneering work for many others to come. References and pictures acknowledgement [1] Coupland, A. (cd.), Reclaunmg the city, mixed use developmen~, E & FN Spon, London, 1997 [2] Wilde, Th.S. (cd.), Construction above tracks, Multiple space use m railway area.! (in Dutch), Dutch Council on Tall Buildings, The Hague, 2001 [3] Vakar, L,I. & Snijder, H. H,, Railway Station Structures Designed for Densily Populated Areas, Structural Engineering International, 11(2), pp. ]~8.138, Zool [4] Wilde, Th.S. de& Vhkar, L. I,, Construction above tracks (in Dutch), I.arrd I W a?er,41(9), pp ,2001 [5] Healey, P,, ea. (eds,), Rebuilding the city, property led urban regeneration, E & FN Spon, London, 1992 [6] Rosehaugh Stanhope Developments plc., Broadgate, Penshurst Press, England, 1988 [7] com (February 2002) [8] Physical Planning Department of Amsterdam, Perspective on the Zu~da.s (in Dutch), Amsterdam, 2001 Holland Railconsult Fig, 1,2,3,4 Rosehaugh Stanhope Developments plc Fig. 5 Editions Quai Rouge Fig, 6 Physical Planning Department of Amsteram Fig. 7