Incremental Façade Retrofits: Curtainwall Technology as a Strategy to Step Existing Buildings toward Zero Net Energy

Current goals for energy efficiency and carbon reduction from the building sector require that much of the existing building stock undergo deep-energy retrofitting, a practice that involves the facade. While new buildings are the most frequent subjects of aggressive performance goals like zero net energy (ZNE), the conversion of existing buildings to enhanced efficiency presents a far greater opportunity to recast the sustainability of the built environment. Yet achieving zero net energy in existing buildings is far more formidable than the abundant challenge presented by new buildings. The practices utilized in accomplishing these façade upgrades will determine whether they are a net benefit or just another burden to the economy, society, and environment. This paper explores the potential of curtainwall technology to contribute to the pursuit of zero net energy performance. Curtainwall systems and renovation practices are examined from the standpoint of energy performance and other sustainability considerations. A ZNE-ready façade strategy is proposed. The conclusions recommend an incremental approach to transformation of the building stock towards zero net energy goals facilitated by the application of adaptive curtainwall technology on both new and existing buildings.