According to Chapter 17 (Construction Impacts) of the Final Environmental Impact Statement (FEIS), the arena would take "less than three years" to build or, by my calculations, 32 months. Even if they started today, the construction schedule would go well into 2011.
Bruce Ratner, speaking to investors in June, somewhat more accurately estimated that the arena would take two-and-a-half years (30 months) to build, though that seems optimistic.
If the developer were to break ground in February, assuming lawsuits are cleared by then, a 32-month (two years, eight months) timetable would still allow for completion for the basketball season beginning in October 2011.
But it sure wouldn't allow for a 2010 arena opening.
What the FEIS says
The document states:
It is expected that the arena construction, including the mass excavation, would take less than three years, ending in the fourth quarter of 2009.
The chapter notes two overlapping phases:
EXCAVATION AND FOUNDATIONS
This phase is expected to last about five months.
LOWER CONCRETE SUPERSTRUCTURE
This phase is the erection of the lower concrete superstructure, which would overlap with the foundation work.
After construction of the lower concrete superstructure, the upper steel superstructure and roof would take about 10 months. Construction of the exteriors would take about 15 to 18 months, beginning about three to four months after the start of the construction of the steel superstructure.
That gets you to a total of 23 months, in a best-case scenario (5+3+15 months), or perhaps 27 months (5+4+18 months).
The 29-month total
But no need to haggle about those numbers, because the five-month initial phase is succeeded by a 24-month phase. Consider this:
INTERIORS AND SEATING
Construction of the interiors and seating is expected to take about 24 months and would commence as soon as the lower concrete superstructure had been constructed.
A total of 32 months
Finally, we get to the phase of Commissioning:
The commissioning process is expected to last about three months and would be the final part of the arena construction prior to its public opening.
Add three months to 29 months and you get 32 months.