Managing Cost and Quality of Large Scale Housing Projects

The economic development, the population growth and the rural-urban migration create a huge demand on the Vietnamese housing market.  At the same moment there is a growing purchasing power, but proposals have to be elaborated within strict budget constraints. Developers, avoiding risks and striving to maximize profit, supply in most cases very stereotype units. The government would like to stimulate the development of the housing stock in a sustainable way but has limited resources.

The basic aim of this research is to develop a simulation tool that is adaptable to specific requirements and expandable in order to come to a win-win-win situation: better quality for end users within budget, opportunities to implement a social policy and reasonable profits for mobilising private funding.

The starting point is the element method for cost control from sketch design to detailed design.  The method is expanded in three ways: (1) better estimating from the first sketch on land cost and costs for pile foundation for high-rise building in soft soil condition of the Mekong delta, (2) taking into account preferences of end users (renters or buyers) derived in a semi-automatic way from selected internet advertising (3) achieving thermal and visual comfort via decision on different scale levels from urban clustering and orientation, over building layout up to material selection. For this last point two original contributions are elaborated: (a) the development of a surrogate model for predicting pressure coefficients (Cp) used to estimate air flow exchange via natural ventilation. (b) the implementation of an “Energy Management System” (EMS) to simulate, via a dynamic modelling, the occupant behaviour to minimize energy use as much as possible with passive means. In a final step the optimization process of life cycle costs is elaborated by coupling a general optimisation software (“GenOpt”) with dynamic energy and light simulations including life cycle costing (“EnergyPlus”) linked to the meta model for estimating costs of pile foundation for high rise buildings in soft soil conditions. The graphical representations of the results of the optimisation can support in the early design phase developers, designers, users and policy makers to come to better solutions.

Due to the modular implementation, in the future many expansions are possible: other climatic contexts, new soil conditions, different economic price levels and predictions, urban and dwelling typologies from another culture, other registered preferences, etc.