Bouwmethodiek voor high-rise woongebouwen: De ontwikkeking van een beslismodel om vroeg in het ontwerpproces de keuze te kunnen maken voor de meest economisch bouwmethode

High-rise residential buildings can be built in a broad variety of manners. The creation of a decision model with which the most economic construction methodology for a specific project can be obtained, was the goal of this research project. It has been carried out in cooperation with the Dutch contracting firm Boele & van Eesteren. Problem definition The choice for the construction method of a building is often based on a contractor’s knowledge, culture, equipment and thoroughness in which a project- and process analysis is carried out. Whether the selected construction method is the most economical is not always analyzed in an integral manner. Furthermore, in case alternative construction methods are analyzed, excess risks on construction costs and construction time are not always explicitly taken into account. Research My research is carried out by answering the following research questions: 1. How is the development of high-rise residential buildings in the Netherlands and which construction methodologies are used? 2. Which construction methodologies are essential for integration into the decision model? 3. In which manner can social developments in the Netherlands influence the choice for a construction methodology? 4. What are, as seen from the building practice’s point of view, the most important project related influence factors on the choice for the construction methodology, and how can these be integrated into a decision model? 5. In which manner can excess risks on construction costs and construction time be efficiently integrated into a cost and time estimation? Results 1. Since 2000, 27 high-rise residential buildings were built and in the coming years another 27 projects are being realized. The construction methodologies that are mostly used are ‘tunnelen’ (48%), ‘prefab’ (24%), ‘klimmen’ (10%), ‘staal’ (5%) and ‘traditioneel’ (2%). 2. Because of the their high degree of repetition, concurring building costs and relatively high building speed, ‘tunnelen’, ‘prefab’, and ‘klimmen’ are essential for integration into the decision model. 3. Working with social responsibility is something that is being done by more an more contractors in the Netherland, but as long as there will not be a financial incentive for this, it will not be a part of the decision model. 4. Influence factors: building time, building costs, contractors expertise, design, market, location and logistics. They can be integrated to select technically possible methods and carry out a design related optimization. 5. Carry out a quantitative risk analysis based on a risk database providing statistical data. Conclusions and recommendations The market for high-rise residential building is growing. A few construction methodologies are leading in use and should always be analyzed in a project analysis. Working with social responsibility is growing but not always integrated as policy. It deserves further research in which way this can be integrated into companies policies. Integrating a quantitative analysis of excess risks can add to choosing the most economic construction methodology. It deserves further research into how this integration can be obtained as well as research into the creation of a risk database.