Construction Engineering 380
Subsurface Conditions
Unforeseen Conditions
• Unforeseen conditions are most commonly
found in remodeling work and subsurface work
(excavation, retention, mining, environmental
remediation)
• Almost all construction places responsibility for
unforeseen conditions on the owner through a
variety of methods, most following the federal
DSC clause guidelines. (the owner pays one
way or another –either through increased cost
upfront or change orders)
Differing & Unforeseen Conditions
• Differing Site Conditions- actual conditions
differ from the representation made in the
contract documents (MSP airport)
• Unforeseen Condition- unusual situation
not reasonably anticipated based on
contract documents
Differing & Unforeseen Conditions
• Contractor is awarded damages for
differing site conditions
• Contractor NOT awarded damages for
unforeseen site conditions unless they rise
to the level of practical impossibility,
commercial senselessness, or there is
contract language transferring risk
(common)
Differing & Unforeseen Conditions
• If the contract is silent, then ONLY
unforeseen conditions can arise
• Unknown physical condition of an unusual
nature that differs materially from those
ordinarily encountered (buried tank
example)
• Doesn’t cover weather, economic
condition, market factors, etc.
Differing & Unforeseen Conditions
• Owner is liable only if
– Risk transfer clause is executed a priori
– Objective or practical impossibility
– Tort claim arises
– Ambiguous contract could be interpreted as
differing (not unforeseen)
Differing & Unforeseen Conditions
• Unforeseen site conditions clause is
standard in most contracts. Can be
invoked if
– Condition is unknown to contractor
– Condition is unusual
– Condition is materially different
Differing & Unforeseen Conditions
• Objective or practical impossibility was
covered in previous lecture (commercial
senselessness)
• Nondisclosure- owner has a duty to report
(widely recognized by most courts). Soil
borings is example
• Tort claim- additional contract clauses to
deal with torts (fraud, negligence,
misrepresentation)
Differing & Unforeseen Conditions
• Ambiguity- need interpretation of whether
the condition is unforeseen or differing
(transfer clause eliminates distinction in
most cases)
• Prebid site inspection- required in most
contracts. Visible conditions cannot be
later claimed as unforeseen or differing