Boston-area developers face a new and seemingly unlikely threat as they struggle to hang onto downtown towers and suburban office projects amid the Great Recession – tax hikes.

The prices of urban towers and Route 128 office palaces alike have plunged dramatically from their boom-time high, forcing some commercial property owners to the edge of foreclosure. Yet as the value of these developments scrapes bottom, local tax bills for many commercial properties are headed up.

The increases will mean millions in added taxes for office owners, all at a time when the commercial real estate market is in the midst of an historic bust.

“This is going to impact some businesses that are really on the edge,” warned David Begelfer, chief executive of NAIOP Massachusetts, which represents local developers.

Putting further pressure on already financially stressed buildings is bad enough, but what’s worse is the prospect for dampening local economic growth, as landlords pass extra charges through to their corporate tenants.

But don’t expect area developers to take the higher taxes sitting down, with some predicting a flood of appeals and litigation.

Buildings Don’t Vote

All eyes right now are on Boston, where tower owners are expected to face a fairly steep tax hike.

City officials recently put the finishing touches on a roughly 8 percent commercial tax rate increase, one that pushes the current rate, of $27.11 per thousand of assessed value, to $29.38.

While the assessed value of the city’s commercial properties is also set to drop by 7 percent or so, the tax rate will grow even more than that.

But a number of suburban towns, which also have their share of office and commercial properties, have already beaten the Hub to the punch.

Waltham, Braintree and Burlington, three major suburban office centers, have all significantly hiked their commercial tax rates. The increase topped 10 percent in Waltham, home to an array of shiny suburban office projects that overlook Route 128.

In addition to hiking the commercial rates, these towns and others, such as Walpole, are also taking advantage of a state law allowing them to push a disproportionate share of the tax burden onto the commercial sector as well.

While the law shields homeowners, it can keep commercial tax bills artificially high – sometimes 10 percent or even 20 percent higher than what they would have been.

In a way it makes sense, as overall tax revenue falls amid the brutal downturn. State government is cutting back on local aid, home values have been falling for years, and health care and pension costs for public employees are soaring, leaving municipalities scrambling to make ends meet.

But cities and towns are putting this burden on commercial property owners for another, very basic reason.

“Buildings don’t vote and people do,” said Larry DiCara, former Boston City Council president and a top local real estate attorney. “If there was a way to pull it off, residents would pay no taxes and buildings would pay for everything.”

Flaws In The Calculus

But this calculus may be more than a little short-sighted.

For starters, there’s the looming foreclosure problem. Some estimates have half of Boston-area office towers and buildings facing the prospect of having to turn the keys over to their lenders.

If you think this is overblown, who would have ever predicted the Hancock Tower foreclosure? Or the New York developer with big plans for the old Polaroid campus in Waltham losing control to its German lenders?

Big tax hikes on top of all this will make space more expensive to lease in buildings that desperately need tenants, at the very least.

Of course, that gets to the second point – many Boston area commercial landlords will simply pass these added costs on to tenants, from start-ups to established law firms. And with companies across the board under tremendous bottom line pressure, any increase in costs could tip the balance toward additional layoffs.

“It’s a substantial amount of money, and again, it’s hitting businesses that are making decisions on whether to hold onto people or let them go,” contends Begelfer.

But the big tax push by local and town officials may just end up backfiring.

While local officials may be desperate for extra cash, the real estate firms that control the Boston area’s sprawling array of towers and office parks also have their backs against the wall.

And more than a few real estate executives, when they get back to work after the holidays and open their tax bills, are going to immediately question why their taxes are going up even though the market value of their office properties is in the tank, predicts John Lynch, a top Boston real estate tax attorney.

After watching commercial property values plunge roughly 40 percent from their peak, many commercial property owners are likely expecting a tax break, not a big increase.

That is likely to lead to a flood of appeals to the state’s Appellate Tax Board, which handles such matters, according to Lynch.

Then, city and town officials can wave goodbye to some of that extra revenue they had banked on.

Instead, it will go to pay the legal fees on complex tax litigation cases against savvy developers who know all too well when they are being used as piggy banks of last resort.