New York based developer Jeff Ravetz and his partner plan to renovate the former Sonesta Hotel on Constitution Plaza in Hartford, turning the property into upscale apartments.

The addition of nearly 1,000 new apartments over the next few years could be what downtown Hartford needs to secure a long-elusive vibrancy beyond the work week.

Five apartment projects are now underway — four conversions and one new complex— and the first of this wave of new rentals are expected to be ready by early fall. Work on an additional half-dozen apartment projects could begin in the next year.

The stakes are high for downtown Hartford. More apartments would foster greater street activity at night and on weekends and provide a key element to revitalizing the city.

Now, finding an apartment downtown isn't easy. The new units are intended to ease the crunch and provide more housing for an expected influx of thousands of state workers and more college students. Developers are also banking on the national trends of people moving back to cities, young people delaying home purchases and baby boomers downsizing.

But the market for another wave of new apartments — mostly studios and one-bedrooms — is untested.

And there may be competition: a similar apartment building boom is happening in surrounding communities. Some of those complexes, less than 10 miles from downtown, could woo away tenants concerned about safety and limited access to amenities such as grocery stores.

Michael W. Freimuth, executive director of the Capital Region Development Authority, said he believes downtown will be in a strong position to compete for tenants. Right now, potential tenants are skipping downtown altogether because of the shortage of rentals, he said.

"You ask where all these people are coming from," Freimuth said. "They may already be here."

One of them is Katherine Donovan, who has been frustrated in her search for an apartment for nearly a year. A senior audit associate at the downtown office of Whittlesey & Hadley, Donovan now lives at her parents' home in Suffield. She wants to find an apartment with a rent where she has enough money left over to save for a down payment for a house.

Donovan likes spending time at Bushnell Park, and the views of the city from her office in the 280 Trumbull tower are appealing. There are plenty of restaurants and night life attractions.

What she really wants to do is eliminate the daily half-hour-to-45-minute commute each way.

"I'd like to be able to walk to work," Donovan, 25, said. "But I'm starting the look outside of downtown."

1,500 And Counting

Downtown Hartford now has nearly 1,500 apartments and a vacancy rate that hovers between 3 percent and 4 percent. Vacancy rates at the newest apartment complexes built a decade ago — Hartford 21, The Lofts at Main & Temple, Trumbull on the Park and others — are all in the low single digits.

CRDA, the driving force behind most of the apartment projects downtown, is betting $60 million in taxpayer-funded loans and other investments on the new rentals. The average amount CRDA is spending per unit is $60,000, or roughly a quarter of the cost.

Aside from demographic trends, Freimuth said there are major sources of tenants in the pipeline: The University of St. Joseph wants 100 apartments for its downtown pharmacy school and the University of Connecticut is establishing a Hartford campus.

On top of that, 3,000 state workers will be transferring to offices downtown in the next couple of years. With expected retirements, younger workers coming on the payroll could become potential renters downtown, Freimuth said.

"If I get just 10 percent of them, that's 300 units," Freimuth said. "These are all things that aren't being measured."

Of the apartments now planned, 200 also are set aside as "affordable," meaning they will have restricted, lower rents for tenants meeting income guidelines.

"We'll rent those before I can breathe," Freimuth said.