Strategic investment of embodied energy during the architectural planning process

It is an interesting time in the building industry; for more than one decade sustainability is a planning parameter that essentially impacts construction related processes. Reduction of operational energy was initiated after the oil crisis and changed the type of construction by including heat transmission as one function of the building skin. The IPCC report added another motivation to produce less emissions: today we know that the amount of greenhouse gases increased during the last 150 years and developed a dimension that changes natural processes and by that, threatens stability enabling human livelihood. Regulations have been developed that define change in design and construction of the built environment: by 2021 new buildings should use nearly zero energy to operate the building. This addresses the operational energy and supports to exploit its potential. Furthermore it shifts the focus to building’s substance: if buildings use nearly zero energy for operation the ecological quality of a building is defined by its materials. The production and demolition of the building substance involves the use of resources and emissions which are quantified with a method named life cycle assessment. The unit to indicate the extent of environmental impact is embodied energy or embodied greenhouse gases. This method monitors material flows and quantifies its ecological consequences. This is especially relevant since 70% of the building mass of new constructions should be reusable or recyclable by 2020. The concept of embodied energy is the background for a series of design and construction decisions. For example it highlights the potential of modularity and prefabrication as they provide good potential for later reuse and by that they reduce the amount of used primary resources. Furthermore it recommends to support closed material cycles by considering the appropriate level of connectivity for adding materials or engages an information management system to enable building element reuse and material recycling. This thesis outlines the relevance of the building substance as factor for the overall sustainable performance of the built environment. It wants to sensibilize the designer for the ecological dimension of planning decisions and to show how to optimize them. Design and construction of buildings include harvesting resources and producing emissions and stating a burden to nature. This can be perceived equivalent to a financial investment where the monetary value has to express adequately the real one. The planning decision has an ecological value which must justify its relevance by function and has to be optimized within its scope. Environmental impact and desired building quality must be alanced in order to establish a sustainable solution. All means to optimize need to be evaluated. In order to do so the designer needs to be aware of his impact and has to strategically invest embodied energy during the architectural planning process.Architecture Engineering and TechnologyArchitecture and The Built Environmen