As Ontario neighbourhoods adapt to accommodate more and more new citizens, the expansion of mass transit, residential housing and infrastructure could have consequences for pre-existing building owners. To limit the impacts of adjacent construction work on older assets with damage potential, many building owners and condominium corporations are turning to independent pre-construction surveys. Conducted by qualified engineers prior to the onset of neighbouring work, these detailed inspections provide a snapshot of an existing property’s condition so that owners are aware of the issues that may be exacerbated by the sustained vibrations cause by construction work.
While in some cities, such as Toronto, developer-led surveys of all neighbouring buildings are mandated before any new development can proceed, structural experts warn that existing assets aren’t being adequately protected given the surveys are more designed as a loss control and claims defense mechanism for the developer.
“For that reason, we recommend to our clients that they allow the developer do their pre-construction survey, then we’ll come in and conduct an independent survey they can directly rely on,” said Justin Tudor, President, Keller Engineering. “Developer-led preconstruction surveys have value, but they are often cursory and may provide insufficient detail to ensure a comprehensive capture of existing conditions. Furthermore, the developer is often not required and is commonly resistant to providing the findings of their pre-construction survey to the owner.”
Referring to an independent pre-construction survey his company recently conducted in Mississauga, Tudor explained that the assessment involved identifying existing cracks in walls, floors, and exterior cladding of the first two storeys above grade, and interior finishes of all storeys below grade to facilitate a comparison once the adjacent construction was complete.
“Although other building elements can be affected by adjacent work, extensive monitoring of elements such as stone facades require detailed investigations and costly initial surveys,” he said. “In our experience, crack creation or propagation in the building’s parking garage and lower levels is the most effective way to monitor for building movements as a result of adjacent construction activities.”
Typical Project Scope
For most independent preconstruction surveys, the scope of the project includes:
- A site review to document the building’s condition, noting existing cracks in foundation walls, and signs of deterioration and settlement. A basic review typically focuses on the first two storeys of exterior cladding, below grade interior walls of common rooms, stairwells, corridors, and parking garage floors, walls and ceiling, but can be expanded to include upper stories by way of drone (if permitted in the area);
- Preparation of video showing the general location and extent of pre-existing deterioration;
- A report on the findings, including a detailed summary with photographic documentation and recommended remedial actions, if required;
- Storage of the documentation for a three-year period.
Benefits for the property owner
According to Tudor, the peace of mind independent pre-construction surveys bring to all types of building owners can’t be underestimated.
“Developments and transit expansions are happening all around us,” he said. “Those excavations will vibrate and potentially damage adjacent properties. Aging buildings need to be documented to capture the difference between what’s fallen apart due to wear, and what’s damaged as the result of the construction.”
With a pre-construction survey, owners can rest assured that the conditions of their building are appropriately documented prior to any adjacent construction activities, so that any resulting damage can be attributed back to the source.
For more information on independent pre-construction surveys and other related services, please visit www.kellerengineering.com
