Exposed concrete slab edges, balconies, and eyebrows on multi-storey buildings bridge the insulation provided by wall and window assemblies, which increases heat transfer between conditioned spaces and the exterior. This can also result in cold interior surface temperatures and condensation/fungal growth during the winter. These impacts are becoming more significant because balcony area is often considered a significant selling point in the condominium market, and many municipalities have been known to offer increased balcony area as an incentive for other variances. Though solutions exist within the marketplace, and have been used successfully, they are seldom employed in North America for a variety of reasons.
This paper examines the impact of concrete slab edges and balcony projections on annual heating and cooling energy consumption in Canadian climate zones. The individual assemblies are analyzed using 3D component thermal modeling to determine overall effective R-values/U-values and linear transmittance values and to assess thermal comfort impacts. Whole-building energy simulations are run to assess the impact on energy consumption. Several potential solutions are also assessed, comparing cost implications in relation to the anticipated energy savings.
This paper was presented at the 2014 Canadian Conference on Building Science and Technology.