The Three Dimensions of Safety, Damage and Recovery Define Your Building's Performance In A Major Disaster
Buildings that achieve a Verified rating with minimum thresholds in each of the three dimensions of Safety, Damage and Recovery will receive either a CERTIFIED, SILVER, GOLD or PLATINUM designation, reflecting their expected level of performance. These designations can be displayed on the buildings themselves with plaques and certificates.
USRC Safety Rating
The USRC SAFETY dimension
reflects the expected performance of the building in terms of loss of
life, injury and egress. An average building designed to modern building codes
should achieve a safety rating of three to four stars.
USRC Damage Rating
The USRC DAMAGE dimension is an estimate of the cost to
repair the building, as a percentage of replacement cost
(not including the replacement of contents). Market conditions following the event such as increases in local construction costs may impact repair
costs, and the Damage dimension does not include factors such as business
interruption losses, historic preservation costs, or mandatory upgrades
triggered by building code regulations.
An average building designed to modern building
codes should achieve a damage rating of two to three stars.
USRC Recovery Rating
The USRC RECOVERY dimension is an estimate of the time until
a property owner or tenant is able to enter and use the building for its basic
intended functions. It represents a minimum timeframe to carry out needed
repairs and remove major safety hazards. Included in the Recovery dimension are
potential delays in design, financing, and construction that may include long-lead
time equipment or materials, a lack of available local design professionals or
contractors, and longer than usual permitting and inspection wait times. It does not address
several other factors that can delay the time to regain function, including:
the condition of external infrastructure (e.g. utilities, transportation);
damage to building contents; or the condition of adjacent buildings.
An average building designed to modern building codes should
achieve a recovery rating of two to three stars.
Seismic hazards correspond to an earthquake ground shaking intensity typically required by codes for the design of a new building. This is not the same as designing for a specific magnitude event, because the shaking intensity at a site depends on how far away major earthquake faults are and the soil on which the building sits.
The USRC is currently developing ratings for other hazards, including wind, wildfire and flood.
USRC Rating Definitions have been derived from technical
publications originally developed by the Structural Engineers Association of
Northern California (SEAONC). SEAONC granted the USRC permission to use these
documents. Any differences between USRC Ratings and related SEAONC documents
are solely the work of the USRC and do not reflect any opinion, endorsement, or
approval by SEAONC.
While US codes and engineering practices are among the most
advanced in the world, evaluations of building performance subject to natural
disasters include a significant amount of uncertainty: unknowns related to
forecasting actual event location, size and duration, the actual intensity to
which the building is subject, and the quality of the building design and
construction. Current building analysis, evaluation and correlation methods do
not address or remove all these sources of uncertainty.
Due to many factors including but not limited to
variations in construction, differing site conditions, and variations in
natural and man-made events, the performance evaluation of a single building
includes a significant amount of uncertainty.