This is an extract of Practical Three, group work with Abdulrahman Al-Metwali & Adina Renner.
Please refer to submission in Moodle for assessment purposes.
Helsinki’s population continues to increase, 860,000 people are expected to call the city home by the year 2050 (City of Helsinki, City Plan, 2016). With demand for housing already high within the Helsinki Municipality, there is a drive to densify built areas, and use plots more efficiently. The master plan of Helsinki (City of Helsinki, City Plan, 2016) is oriented to control the urban sprawl. Achieving a balance between increasing density of suburban areas and retaining livability and character is fundamental. Building efficiency ratios are one planning tool which can be used to describe the current level of land use intensity on a certain area at different spatial scales. The building efficiency ratio is a calculation of the total floor area of each story of a building by the size of the land it is on. The idea is, the higher the ratio, the more built-up or ‘urban’ an area is.Efficiency ratios can aid planners in identifying areas for potential development. Further, it be used to examine placement of services, transportation and amenities (Gordon and Vipond, 2005).
This paper uses QGIS tools to examine efficiency ratios at two different spatial scales in Helsinki: City district level and a 250m grid. It further examines how efficiency ratios describe urbanity in Helsinki.
On a regional scale, the areas with the highest efficiency ratio are located within the central area of Helsinki (see Map One). These include the district areas of Kampi and Punavuori which had the highest regional efficiencies of 2.03 and 1.68 respectively. Kallio, Kaartinkaupunki and Kluuvi also had regional efficiencies greater than 1.5. These areas are built up and contain many multi-story buildings including apartment blocks and businesses. Areas with regional efficiencies of less than 0.05 were either located in the north eastern region of Helsinki or the southern islands.
Map One Regional Efficiency Helsinki 2016
Interestingly, 10 regions had an efficiency score of zero ( Ultuna, Östersundom, Talosaari, Salmenkallio, Vartiosaari, Ulkosaaret, Villinki, Suomenlinna, Santahamina and Mustikkamaa-Korkeasaari). This does not indicate zero ‘floor area’ or no buildings in these areas. It indicates that these areas are sparsely built and the precision of our calculations was not high enough to pick up the small amount of floor area as ratio to total land area. Also, water areas are included in the total area calculations for the islands, hence making the total land area higher. There is a strong correlation between Map One “Regional Efficiency Helsinki 2016” and the map from Practical 1 showing the percentage of Green Area within each city district of Helsinki. ÖSTERSUNDOM, SALMENKALLIO and ULTUNA were areas with over 45% percentage of green space identified in Practical 1. Therefore, these areas are mostly green space and contain a small proportion of built floor area.
Map Two Block Efficiency Helsinki 2013
Map Two “Block Efficiency Helsinki 2013”, examines efficiency ratio at a per a 250m x 250m grid across the Helsinki Municipality. At this smaller spatial scale the general trend of high efficiency areas could be seen. More of a breakdown across regional areas was evident, for example at a regional scale the whole of Vousaari has an efficiency of less than 0.16 but when examined on a block scale, the areas with a high efficiency of over 0.70.
Across the three spatial scales examined in the exercise, the major trend of high efficiency in the CBD and lower efficiencies on the islands and in the north east of Helsinki are visible. However, the accuracy and detail of the efficiency ratio improves when examining efficiency at smaller scales such as block or plot level. The grid and plot analysis show more detailed description of the efficiency than the regional analysis and allows us to study the area more specifically. These scales show there is a diversity of efficiency ratios across a region and highlight that false assumptions could be made if regional ratios are used to examine land use intensity. Geographical features such as the Central Park, Vantaa River and forests around Östersundom, and Ultuna are not visible on “Regional Efficiency Helsinki 2016”.
When switching scales, the diversity in efficiencies is also shown. Areas of high and low efficiencies are clearly evident within the one region of Helsinki. When looking at ‘urbanity’, the efficiency ratio is not an accurate measure. A single-story warehouse or store such as Ikea show a higher efficiency ratio if compared in the same area with single detached houses. This is evident in Pitäjänmäki – in industrial areas dominated by large warehouses – which has a block efficiency ratio of up to 1.6. It could be assumed that the detached houses have more people in them and may seem more ‘urban’. If ‘urbanisity is used in the context of density of people and provision of services. Efficiency ratios do not show the diversity of types of buildings within a certain area and therefore it is hard to make assumptions on urbanity. Furthermore, the efficiency measure does not describe the amount of people living in an area and should not be used as a tool to examine population density. The issue of this urbanity analysis is that built environment efficiency is described only in terms of built area. The visualization would probably describe more the term “urbanity” if joined with land use (e.g. if the buildings are for commercial use), population density.