From the Seaport to the Fenway to the North End, a bevy of super-ambitious developers want to redraw Boston’s skyline with dazzling new skyscrapers.

Too bad then that most of these glimmering new towers will never get built.

It’s not clear where the starry-eyed real estate moguls pushing these new towers think the demand for millions of square feet of new office space will come from, but maybe some of these would-be city builders should spend some time exploring the Financial District, which still has more than a few empty blocks of office space to fill.

And while the outlook for new deluxe residences may be a bit brighter, do we really need several thousand more of these cookie-cutter crash pads for the rich? After all, not everyone is a multimillionaire these days.

No, Boston’s building boom – if you call all these glossy proposals that – is based more on illusion and wishful thinking than cold, hard facts.

Pipe Dream Projects?

The sheer volume of new office and residential construction being proposed right now would be a challenge for the Big Apple to absorb, let alone little old Boston.

Another 2 to 3 million square feet of office space is being planned for the Seaport/Innovation District, with twin megaprojects, Fan Pier and Seaport Square leading the way. Not far away, HYM Investment Group, headed locally by former Boston Redevelopment Authority chieftain Thomas O’Brien, would tear down the equally hideous Government Center Garage and put up a massive mixed-use complex that would include another 1.3 million square feet of office space.

And roughly another million square feet of office space is in twin towers planned for the Garden; and in Downtown Crossing, under Millennium’s plan to refurbish the old Filene’s building and put up a new tower next door.

That’s not counting a new 200,000-square-foot office building hotelier Ron Druker is pushing for Boylston Street and the now decades-old South Station tower proposal, which, if it ever moves forward, would easily add several hundred thousand more square feet of office space to the market.

So developers are either anticipating the economy’s tepid half recovery will shift overnight into a roaring, ’80s-style boom, or they are completely out of their heads. I’m inclined to think the latter.

Currently, the vacancy rate for the Boston office market is still well within the double digits, at 13.7 percent, while the rate for Class A, top-shelf space in the almighty Financial District is closer to 15 percent, according a recent market report by Colliers International. In fact, there are enough empty office corporate suites right now in Boston to easily satiate 1.5 million square feet a year of new expansion by financial service giants and law firms, the core of the Boston office market, right through 2015, Colliers finds.

That’s without building one single additional square foot of office space.

And even at that torrid rate, the vacancy rate would still be in the double digits in 2015, though a bit lower, at 11 percent, the firm finds.

So the big question is, where will all the additional demand come from to fill this flood of new office space being sketched out?

Don’t Get Fooled Again

Many of Boston’s corporate stalwarts have already cut separate deals to build their own headquarters, including Liberty Mutual and State Street.

Meanwhile, there are only so many high-tech or life sciences giants interested in making the jump across the Charles from red-hot Cambridge to Boston, leaving the usual suspects – law firms and financial services – to pick up the slack. Respectable sectors of the local economy, to be sure, but not exactly huge growth areas.

And if all this new office space being contemplated is simply silly, the flood of ultra-pricey new condos and apartments currently in the planning is absolutely foolish.

Glossy renderings of glitzy new hotel and condo/apartment towers are popping up everywhere, with high-rises for the rich being eyed for Government Center, Downtown Crossing, the Christian Science Plaza and down along the Seaport.

Sorry, but this is an idea that has come and gone, with the likes of Trinity Place and the Mandarin Oriental.

Sure, maybe there’s room for a couple more of these cookie-cutter towers, but five or six?

These projects are about as exciting and creative right now as suburban McMansions and “lifestyle” centers. Big yawn.

It took literally years for the current batch of luxury towers – recall the W Boston’s breather in bankruptcy – to sell out their units.

And no, you can’t blame it all on the economy, with the downtown market holding up pretty well over the past few years.

If you want to know how many of these new Boston megaprojects will actually get built, just look at what’s happened in recent decades.

Both the 1990s and the 2000s saw one or two new towers added to the skyline each decade. Lots of other stuff was proposed, but only a few projects made it.

Don’t get fooled by the headlines and the hype. When it comes to building towers in Boston, lots of developers are called, but few are chosen. Or can hack the nuttiness of the city’s vetting process, but that’s a story for another day. 

Scott Van Voorhis can be reached at sbvanvoorhis@hotmail.com.