High Rise Ability

In the Netherlands, the number of realized high-rise projects is limited. Research on investment costs of high-rise buildings is project based. The presented research is the integration and evaluation of known (European) researches into a cost model. The objective is to get a detailed estimation of building costs of high-rise office buildings in the initiative and early design phase, while limiting the number of required design parameters to those known at the initiative phase. The research started with a state-of-the-art literature review, and by interviewing experts working on high-rise projects and cost modelling. This resulted in an integrated model, which is now being evaluated in practice. The outcome will be a model that can be used for future design and construction initiatives. However, building costs are only part of the steering attributes for the developer. Their importance is relative to other conditions. The earning capacity of high rise office buildings is, compared to low-rise, bound to efficiency of floor plans: the ratio of gross floor area versus lettable floor area. At the same time costs of land are also very important. As is the case for rent levels the land costs are most of all depending on the location. These influences lead to designs in which high quality is needed in order to meet the high costs. Due to national legislation and other local influences the outcome is bound to the Dutch context. Extension to a European level can make local influences explicit and adaptable to other countries.