Big real estate deals accompanied by many jobs are rare in downtown Ann Arbor, which has the allure for a major employer but not enough of the building spaces to accommodate them.

We still see residential deals: New construction of apartments, both under way and proposed, still transforms the edges of the University of Michigan campus.

We’re also seeing apartment buildings sold and listed, and even Ashley Terrace, the under-capacity mixed use condo high-rise on West Huron, reportedly is finding a new owner. The most significant recent commercial sale was the former Ann Arbor News building on South Division.

Yet the largest office deals are self-limiting for companies that want to remain downtown: Few large spaces exist. A company that needs 15,000 square feet will have a few options, but there isn’t much beyond that.

But need 100,000 square feet? Or 40,000 with room to reach that six-figure milestone?

Rare.

That’s why the announcement last week that Barracuda Networks wants that much space in downtown is so compelling for Ann Arbor.

It reminds us of the potential to develop here and to reach the density goals set nearly a decade ago by planners and business advocates. But now - unlike the peak of the rush to build in the city’s core - we’re talking about office space. Jobs. People who’ll populate the streets during the daytime and just might find a way to live here, too. It’s a picture that flips that development goal that we sought in recent years: Building the residential base so that people who live in the central business district could boost the local economy, even if they left town for work.

The potential for housing downtown - mostly in condominium form - was deemed nearly limitless. How else could we explain 2,000 new units in the pipeline at one time, and so many of them costing $400,000 or more?

We got mired in questions: Where will they park? Don’t we need a grocery store? What if chain stores follow?

All of the introspection generated by those questions seems wasted now. The truth, as exposed by the economic downturn but lurking in the shadows the entire time: There really isn’t a limitless market for downtown housing, especially when you price it beyond the reach of many young professionals.

That’s particularly true since downtown remains defined by the same vibrant streets and slower side streets that always formed downtown, despite efforts to extend its borders.

While many proposed residential projects didn’t happen, some - like Liberty Lofts - did. The gain in the number of residents is felt. Downtown can now support a CVS on South State. Commercial space is growing on East Washington because it can find customers.

However, we may never again see the rush to build housing downtown like we did in 2005. But we still have room for improvement in the numbers of people who spend time downtown.

The pendulum, as they say, is swinging.

Today, a new shaping of downtown won’t come from proponents of major housing developments lining up at the city’s Planning Department.

Instead, the Barracuda announcement dovetails with the new attitude toward downtown development: Filling the commercial district with workstations - not beds - will aid the viability of downtown.

Instead of residents, we have a new appreciation for the daytime worker and the benefits they bring. Ann Arbor’s downtown now wants its office employees back, and it wants to attract new ones.

Those workers will “fill the clock” on our city streets, returning a lunchtime rush and ability of a merchant to make sales outside of the nightlife scene.

They’ll fill the void that major employees left when they moved from downtown in the last decade.

Even before city officials could prioritize that shift, Barracuda raised the bar of expectations. Suddenly, we can hope for up to 500 workers.

And even those among us who recognize that Google promised hundreds more employees than it has in Ann Arbor also can see that its presence counts as an economic driver.

Filling our office space and looking for viable ways to increase it makes sense for Ann Arbor, especially as the national economy tells us we should be headed for a rebound.

And if we can find a way to fulfill Barracuda’s vision for itself downtown, the move could jumpstart a significant economic development movement for the core of Ann Arbor.

Paula Gardner is news director of AnnArbor.com. Contact her by email or 734-623-2586.