Commercial space needs to be capped to keep the 800-acre "Science City" in Shady Grove from being stymied by infrastructure costs, County Executive Isiah Leggett said in a report released today.

Scaling back construction of research, office, retail, academic and health care space to 18 million square feet instead of 20 million square feet, as outlined in the County Planning Board's version of the Gaithersburg West Master Plan, will eliminate the need to build at least two of the five highway interchanges envisioned for the area, which would cost $250 million and require several homes to be demolished.

However, it would also cut the county's net fiscal benefit from $43 million to $31 million per year, according to the report.

Leggett (D) issued his report ahead of a pair of public hearings before the County Council at 7:30 p.m. Sept. 15 and 17 at 100 Maryland Ave. in Rockville.

Two years have passed since plans first surfaced for catapulting the Shady Grove Life Sciences Center — already the state's largest hub of biotech and research — from a suburban-style research park of 6.9 million square feet into a live-work "Science City" of 20 million square feet of commercial and retail space, up to 9,000 residences and more than 40,000 new jobs.

Along the way, Gaithersburg West has rallied the county's economic and scientific community while bringing unease to surrounding neighborhoods.

Leggett framed Gaithersburg West as a "critical component" to creating a "community of innovation," and a "unique opportunity" to establish the county as a life sciences leader and "help carry the County through much of the first half of this century."

"[T]he Gaithersburg West Master Plan is part of an answer to a call to action that cannot go unheeded," Leggett wrote. "Unfortunately, we are losing scientists and we are losing our competitive advantage in the biotechnology industry as a county, as a state and as a nation. This is a loss that we cannot afford."

To expand the Life Sciences Center beyond the 8.2 million square feet already built or approved, the planning board's draft of Gaithersburg West breaks the construction into stages that cannot begin without specific improvements to infrastructure and transportation.

Leggett followed the recommendation of a panel of residents and business leaders, calling on the County Council to create "exceptions" to that staging plan "for projects of strategic economic significance so that the County does not lose economically significant opportunities because of staging restrictions."

For example, under the planning board's version of Gaithersburg West, the third stage cannot begin until two highway interchanges are completed and the other three are funded.

"This raises a serious question as to whether the plan will ever successfully move past Stage 2," Leggett wrote.

However, what would constitute a valid "exception" has not yet been firmly defined.

"What we're talking about there is projects of such importance, either in terms of attracting or retaining projects of significant economic advantage," said Leggett spokesman Patrick K. Lacefield, citing a hypothetical of "if we needed the flexibility to do X to keep NIH from moving from here to there."

Gaithersburg city leaders say the staging plan is an unnegotiable prerequisite for their support of Gaithersburg West.

"The only thing that makes this acceptable at any level is the staging," City Councilman Michael A. Sesma said Monday night as the mayor and council took their stand on Gaithersburg West.

Gaithersburg leaders called for the strongest terms possible to ensure that the County Council include the staging plan in the final version of Gaithersburg West, particularly the funding of a mass transit line — the Corridor Cities Transitway. The County Council stripped a similar staging plan from the master plan it recently approved for Germantown.

Even with the staging plan, the mayor and council complained that Gaithersburg West completely alters the suburban feel of surrounding communities.

"The lack of integration of existing suburban neighborhoods — whether they're in the city or outside of the city —across the street, across the large avenues from the Belward Farm and the Life Sciences Center has not been done very well," Sesma said. "And so they're going to create a mixed-use development that basically isolates itself from the other communities that already exist."