By Tracy Dacko
Today’s new senior residences appeal to a growing customer base by offering the comfort previously associated with high-end apartments and condominium living.
Skylights, green roofs, balconies, courtyards, nature walks, theatres, fountains, and other amenities abound. However, less obvious but critical to the comfort and health of seniors are warm interior floors adjacent to exterior walls and doors, and mould-free air recirculating within the sealed building envelope—improvements which were made possible by insulating concrete and steel structures that penetrate the building envelope.
Correcting an old problem caused a new one
While architects employ a myriad of techniques to incrementally reduce heat from escaping through walls and ceilings, heat energy often finds an easy escape route through thermal bridges. A thermal bridge is created when highly conductive components, such as the concrete slab of a balcony or the steel beam that supports an entranceway canopy, penetrate the insulated building envelope.
When winter temperatures chill the outside air, the obvious outcomes are high heating costs and cold interior floors, but building owners now face an even larger problem: condensation and mould caused by the higher interior humidity of today’s well-sealed buildings.
Prior to air-tight building envelopes, air leakage caused interior humidity levels to equalize with exterior humidity levels of approximately 25 per cent during cold winter months, which is too low for cold interior structures to reach dew point or form condensation.
With interior humidity levels now ranging from 40 to 50 per cent, the interior side of chilled penetrations can reach dew point, form condensation, and support mould growth on adjacent interior surfaces and in stagnant cavities. Mould can become airborne years before it becomes visible on interior walls and ceilings, exposing building owners to significant liability and remediation costs.
Insulating against energy waste, chilled floors, mould growth, and additional costs
Balconies, slab edges, eyebrows, canopies, parapets, rooftop equipment, connections, and other structural penetrations can be insulated by installing structural thermal breaks at the building envelope.
Thermal breaks reduce heat loss at the penetrations by up to 90 per cent, often allowing a corresponding reduction in HVAC mechanical system size/capacity, capital cost, and operational cost. Since penetrations remain too warm to reach dew point, form condensation, or support mould growth, the building owner also avoids related liability and remediation costs.
Structural thermal breaks raise the temperature of interior floors adjacent to penetrations by up to 34 F (19 C), allowing senior occupants to enjoy greater comfort and usable space. The elimination of thermal bridging is increasingly required in building codes and certifications. Vancouver’s code calls for eliminating all thermal bridging in the building envelope. Passive House buildings aim to minimize minimal thermal bridging and provide continuous insulation (ci) throughout the building envelope to reduce heating/cooling demand and improve comfort.
