[I have said many times that the legal principles that will apply to green building projects will be very similar to existing legal principles in the construction law field. On Fridays we will be reviewing legal developments from the construction industry that most likely will be applied to green building projects.] 
When I prepare construction claims for clients, one of the first steps is to gather the facts and develop potential legal bases for the claims. There is one legal basis that clients seem to know, and argue for, more than any other: Differing Site Conditions.
A Differing Site Condition is essentially an unanticipated physical condition encountered by a contractor at a project site, which requires additional work by the contractor. Most federal contracts contain a Differing-Site-Condition clause. As described in Foster Constr. C.A. & Williams Bros. Co. v. U.S.:
"The purpose of a [differing site] conditions clause is thus to take at least some of the gamble on subsurface conditions out of bidding. Bidders need not weigh the cost and ease of making their own borings against the risk of encountering an adverse subsurface, and they need not consider how large a contingency should be added to the bid to cover the risk."
The typical example of a Differing Site Condition occurs when boulders or other large objects are unexpectedly found below the surface and require removal prior to construction.
Contractors often want to argue that a non-physical condition constitutes a Differing Site Condition. Here are two examples of non-physical conditions that I have seen argued as Differing Site Conditions:
1. The contractor expected certain labor conditions in the surrounding area. When he started the project, labor conditions had changed due to a competing project.
2. The contractor properly relies on site boundaries in preparing its bid. When the project starts, the site boundaries change.
Do you think these two scenarios constitute an actionable Differing-Site-Conditions claim? Photo: ubac
