Prefab Facades – from Prototype to Product?

Building envelopes are not only an immediately visible part of the building, they have also become a major factor both for cost and performance of the building. Facades significantly affect the environmental performance of a building due to their passive contribution to operational energy demand as well as their embodied carbon linked to each life cycle phase.
Thus, the importance of prefabrication is growing in the building industry as it allows faster construction whilst achieving high quality in a cost-effective manner. Although prefabrication for structural components or entire walls, cores and floorplates are a relatively recent development, it has already been widely used in the manufacturing of building envelopes, particularly in the case of unitized curtain wall systems. Curtain walls consist of prefabricated, interlocking elements spanning from story to story forming the weather tight building envelope that is suspended from the slab-edge and hence wraps the building like a ‘curtain’. Assembly of units under controlled factory conditions allows for higher precision, resulting in improved quality and reduced risk of failure by limiting the on-site labor to a minimum.

One of the major challenges faced by engineers during the early phases of the building design process is to continuously support the architectural team by rapidly developing technically viable and economically feasible solutions which achieve the desired design intent, often for several design options and iterations.

This paper outlines an approach addressing this challenge, attempting to bridge the gap between design, fabrication and installation. New tools are presented that allow designers to iteratively validate concepts based on a pre-engineered system that is optimized for performance and takes fabrication, transport and installation costs as well as maintenance and circularity into account.