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Building Health Sciences - Healthy buildings, healthy people, healthy business

Mold in Senior Living Facility


A newly constructed three story senior living facility with 150 rooms developed visible mold amplification in a few of the initially occupied units around the punched window openings and in various locations along the exterior perimeter walls. Building construction was pre-cast concrete panels with an individual HVAC system for each of six different residential unit footprints. It houses an elderly population with individual conditions ranging from no health issues to multiple medical conditions and non-specific health complaints unrelated to the building. Initial occupancy was sparse. Increased occupancy was jeopardized and seemed unachievable. Continued occupancy was threatened.


BHS was engaged by the owner to investigate the extent of mold and root cause. Destructive investigation was required in three stacked units. Within the exterior wall assembly, the investigation revealed thermal bridging, temperature anomalies, thermal shorts and ice buildup on the interior of the pre-stressed concrete panels. Additional investigations were required and performed in conjunction with the original design team and general contractor. BHS developed a parallel strategy to facilitate continued occupancy through implementation of a medically-monitored sampling plan, town hall meetings, root cause investigation and interim remediation management tracking simultaneously with collaborative building science investigation and re-design. Ultimately, it was determined that the building envelope’s tightness was problematic, along with pathways that permitted moist, conditioned, high relative humidity, indoor air to move by differential pressure to the exterior wall. At the outside wall interface, humidity condensed into ice, melted and created sufficient moisture for mold amplification. Insertion of BHS’ health component to a building science challenge presented a medically-engineered solution that formed the basis for a successful, managed response to a series of critical environmental construction defects – both in workmanship and original design. This was a building wide condition whose tipping point was the increase in relative humidity generated by tenants occupying the unit. BHS’ medical officer provided risk communication for the concerned residents and their families, informing them contemporaneously of the findings and the proposed corrections. Remediation protocols and schedules were developed with medical input to protect the vulnerable residents. Occupancy was maintained and actually increased; no evacuation was needed.

Lessons Learned

Given the patience to investigate, willing co-operation from collaborative owners, contractors, investigators aided by medical oversight, the focus and costs can be directed most efficiently at the solution path. Litigation may assess blame but it does not provide the ultimate corrective solution. A group such as BHS, with health expertise, environmental building science knowledge, communication skills, and credibility must be an integral part of any building failure effort, in order to mitigate unnecessary costs and pursue timely resolution. Building science differs from punch-list corrections to original work prior to building occupancy. It frequently is triggered by occupancy dynamics which means “people” and people translates to the need for a health component. Healthy buildings mean healthy people and healthy business.