NEW YORK ( TheStreet) -- Small businesses looking for office space may find themselves drawn to charming vintage loft spaces or older buildings with atmosphere -- there's nothing quite like vaulted ceilings and exposed brick to add creative flare.

Although hardwood flooring and winding metal staircases may be more likely to wow clients and make employees feel at home, serious renovations and costly improvements are often necessary to bring older buildings up to standard. To prevent your loft space dreams from turning into a nightmare, experts advise finding out exactly how much it's going to cost and what you'll need to do to bring your office space up to modern standards.

Most small business owners planning a renovation can expect to spend between $20 and $60 per square foot, says Mark Hemmeter, CEO of Office Evolution, a Colorado-based small-business office space provider. Since around 90% of small businesses lease space rather than buy, Hemmeter says, gut renovations are not always worth the money invested.

"That's a lot of capital out of pocket, especially if it's a space you're just leasing," Hemmeter says. "Keep in mind that any renovations you put into the place, when you leave the building, you leave them with the landlord."

Also, Hemmeter points out that most leases on commercial space are for between three and seven years, "a huge commitment in today's world."

"To get your money out of the renovation, you'll need to lease a space for at least five or seven years, and are you really sure that making that big of a commitment is right for your company?" asks Hemmeter, adding that most small businesses have to remain fluid to remain successful. If your company grows or shrinks dramatically or relocation is necessary before the lease is up, you're stuck.

"Really, every tenant in the world right now is trying to be less committed to their space, looking for ways to have people work remotely or work out of shared common rooms," he says. "The most important thing that any small-business owner can do is seriously evaluate a space before they sign on the dotted line. Where will you be in five, 10 years?"

Even with these concerns, many small businesses are taking the plunge -- loft spaces are in high demand, Hemmeter says. Unfortunately, many businesses are trying to do too much by themselves.

"One of the main mistakes we see people making is that they try to design the space themselves. We all think we can draw walls and say, 'This is how the room should flow,' but getting a space planner or an architect makes a huge difference," he says. "Ending up in a space that's not usable an ineffective is one of the worst things that can happen to a business."

One thing that takes many businesses by surprise is trouble with Internet connectivity, Hemmeter adds. Nowadays, people have a tendency to think that the Internet is "everywhere," but older spaces often struggle to keep pace with more modern office buildings.

"Especially in some of the loft buildings, sometimes there just isn't good Internet," he says. "It might sound silly, but we often see thick walls that Wi-Fi can't penetrate, and older DSL cables that break or get flooded easily."

Before you lease or buy a space, Hemmeter advises asking about Internet connectivity; there may be no easy or cheap fix available if a problem goes throughout an entire building.

"Old technology in old buildings can really negatively impact any business," he says.

Some problems may actually occur outside your space, says Richard Lehman, executive vice president of principal interior design at Environetics, an interior and architectural design firm. Lehman says parking for employees and restrictions on the size and positioning of signs can also be a huge problem with older spaces.

"One of the most important things to look out for is the number of parking spaces available, which determines what a building or space can be used for," Lehman says. "You also want to know any restrictions on signage, because many municipalities have strict guidelines."

A lawyer and/or a contractor can help you work out the particulars with city codes that may affect signs and parking, but Hemmeter cautions against spending too much on legal fees.

"You have to manage your interactions with lawyers because they can run up a big bill quickly," he says. "Your contractor should absolutely know what code requirements are, and you should rely on them for that, because code stuff can drive people crazy."

Although keeping costs low is a priority for any restoration, Hemmeter says saving a few dollars by cutting corners isn't an option. If a building isn't renovated to code, inspectors will catch it, he says.

"If you don't do things to code, only bad things happen," he says. "People think they can do it and it's 'good enough,' but it's going to be horrible when you have inspectors on your tail two days after your business opens and you realize you wasted a bunch of money," he says.

Any small-business owner seriously considering a renovation should be aware that you don't have complete control over how much it will cost. Even if you budget carefully, it's probably going to cost more than you think it is, says Rob Carpenter, owner of Mr. Handyman, who is undergoing his own renovations for his Frederick, Md., office space.

"My budget has doubled," Carpenter says of his renovations, which were budgeted at $60,000 to $70,000 but will end up costing closer to $125,000. "I own a handyman company, and even I've been surprised at some of the things we've had to do."

Many small businesses have "grandiose ideas" of what they want to do until they put pen to paper for cost, Carpenter says, adding that the biggest expenses for his renovation have been the electrical system, the heating system and a roof.

"Keep in mind that if you want to add rooms and move walls, you may have to completely rewire your office," Carpenter says. "Also, once we put up new walls, blocked some areas off and opened others up, we realized that the furnace wasn't going to do what we wanted. That was a $25,000 hit once we repaired the duct work that wasn't up to code," he says.

But even though his costs have been much higher than expected, Carpenter says he has no regrets, and encourages other small businesses to take the plunge if it feels like the time is right -- and the money is in the bank.

"It's going to be awesome," he says. "If you're prepared and you and your team can see what's coming, then go for it."

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