The plan to create a nearly 1.3 million-square-foot, mixed-use project on the former Polaroid campus in Waltham is ambitious and risky, to say the least. But the greater risk may be to Waltham’s long-term viability as an office destination if it isn’t built.

When all is said and done, the project is likely to include upwards of 500,000 square feet of new office space and more than 160,000 square feet of retail properties. It could also be the location of a new hotel or residential space. But according to many commercial real estate executives, the most promising highlights of the project also serve to fill Waltham’s most pressing need – new retail amenities, namely the ones that developer Sam Park’s project is expected to deliver. Those include things like a Market Basket grocer, restaurants and other stores that the areas surrounding the town’s office parks desperately lack.

These days, tenants are increasingly choosing to locate their offices in properties within walking distance to places to get lunch, run errands, have dinner or catch a movie after work. Waltham has few or none of those, according to real estate professionals.

Still, Waltham is not exactly hurting for tenants. It’s the place to be for many software and other technology companies. But it is hurting for the kinds of retail and entertainment benefits enjoyed by office tenants in nearby Burlington, which has attracted many of the types of companies that industry executives say flocked to Waltham for years. Work/Life Balance

In the past year, Burlington’s office availability rate has fallen to 15.9 percent, according to information provided by Cassidy Turley FHO. Waltham’s availability rate has also declined in the past year, but only to 21.4 percent.

“Tenants are really focused on amenities, quality of life, having a work/life balance, so that an office building in the woods with a little café in the building and nothing else is kind of a dinosaur,” said Duncan Gratton, senior managing director at Cassidy Turley FHO in Boston.

And so Burlington, with its mall and entertainment, is for the first time outperforming Waltham and starting to close the rental rate gap. Over the past 25 years, Gratton said there’s been a solid $10 spread per foot between the higher-priced Waltham and cheaper Burlington. Today, the top rents in Waltham are at $35 a foot, while Burlington is up to $31 a foot in some cases.

And while the widening of Route 3 a few years back certainly helped Burlington catch up, many industry professionals cites the town’s restaurants, shops and other amenities – many within walking distance to major Burlington office parks.

“Waltham is still a very desirable location, but until now, Waltham hasn’t started to adapt to this changing environment where tenants and employers are demanding more amenities where they’re locating their offices,” Gratton added.

Even so, Waltham is and will continue to be a strong market for office tenants, despite it being weak for retail offerings, said Ted Tye, managing partner with National Development.

And it won’t lack retail for long.

There are plenty of high-tech firms interested in the first office building that Park is preparing, a renovation of a former Polaroid property that will total about 120,000 square feet of office space, according to Gratton, whose firm is marketing the property. Some of those companies expressing interest are already located on Route 128, Gratton said, though he declined to name names. He claimed there’s even one firm from downtown Boston considering the space, scheduled to be finished by the end of 2013. Start of construction on the first retail phase is set for the end of 2013.

Better Late Than Never?

And Park isn’t the only Waltham developer planning new retail space. Boston Properties is considering building “a Liberty Wharf kind of restaurant building,” with three or four eateries on Prospect Hill, as part of its CityPoint project.

“I think Waltham is late to the party, but it’s going to fight back,” Gratton opined. “Restaurants and entertainment are coming and it’ll be interesting to see how successful it is. Waltham won’t just fade away, but it has to compe ste.”

And it will soon have plenty of ammo to bring to the competition. Boston Properties’ 450,000-square-foot, mixed-use CityPoint project is permitted for about 400,000 square feet of office space across two, six-story buildings, and 50,000 square feet of retail shops and restaurants.

Davis Marcus Partners’ Reservoir Woods East and West campuses in Waltham are permitted for 440,000 square feet and 370,000 square feet of additional development, respectively. Expect a good proportion of that to be retail, as well.

But while Park’s project is expected to be a boon for area amenities, he has yet to solve the puzzle of increased traffic that will inevitably accompany such an in crease of office and retail space, industry professionals say.

“Park’s is a great site and highly visible,” said Mark Roth, an executive director for Cushman & Wakefield. “You’ll always have competition, but the bigger question is who has the infrastructure required to make a tenant feel comfortable. That’s where he needs to get some work done. Highways, ramps, access. When you’re talking about several hundred thousand additional square feet, the timing of those improvements has to be clear to the corporate user. Typically they want to know that before they commit. Those are hurdles he has to overcome. If he can do a million square feet on one piece of land, that makes him unique. There aren’t a lot of tenants that need that much space, but if they come along, he’ll have it.”