Ever hear those stories about families who rent a vacation house together? Rarely does it turn out well, especially the first time. Count on disagreements over children’s bedtimes, room allocations, paying for food and clean-up. Now multiply those decisions by thousands and you have what meeting planners and executives face when they try to co-locate a meeting together.

“The potential for disaster is definitely there,” says Steve Warner, president of the Industrial Fabrics Association International (IFAI) in Roseville, Minn. “We clashed a few times when we started co-locating. But it can work and there can be a lot of benefits.”

With the tough economy, associations and companies are looking to cut costs and boost attendance. Sharing the price of exhibit space, vendors, marketing, and other expenses along with the discounts that come with booking large blocks of hotel rooms can be appealing. In many cases, attendees on a tight budget may not have to choose which meeting to attend and which one to skip.

“I wouldn’t say co-locating is a trend, maybe it’s becoming a trend,” says Joan L. Eisenstodt, president of Washington, D.C.-based Eisenstodt & Associations. “I hear a lot of people talking about it. I recommend proceeding very cautiously. You lose some of the brand and identity unless you do it very carefully. It’s problematic. But, if it is a good fit, it might make sense.”

So besides cost — and let’s face it, that’s a pretty good reason — why else does co-locating make sense?

For one thing, it may energize the meeting.

When the Society for Values in Higher Education (SVHE) co-located with the Reacting to the Past, a group that recreates and explores historical events, SVHE saw their members uplifted by the mingling. “Our members were fascinated with the other group. They loved watching them perform and they were much younger than we were,” says Pam Montgomery, who coordinated the event for SVHE. “And, the other group was impressed by us. For us, it was like ‘Wow! We are cool.’ It was like a shot in the arm and we looked at our own organization and realized that we really do have value. Each group validated the other.”

In fact, SVHE picked up new members from the Reacting to the Past group.

The IFAI co-locates its meetings with the American Textile Machinery Association (ATMA) and as a result they were able to show attendees everything from processes and products to fiber and retail. Essentially, it gave attendees a bigger bang for their buck.

“We were not competitors and our exhibitors were their (ATMA) exhibitors’ customers. They wandered a lot over to our exhibits and did business. Maybe five percent of our exhibitors were interested in their exhibitors, but they did wander over,” Warner says.

An unexpected — but welcomed — benefit of co-locating was that the U.S. Department of Commerce awarded them its highly sought-after International Buyer Program (IBP), which is designed to boost international attendance at U.S.-based trade shows and create international business opportunities for show exhibitors.

“We had a lot of benefits from co-locating such as better hall rental costs and saving costs all around, but the IBP designation really nailed it for us. Neither organization would have gotten it on its own,” Warner says.

Selecting an association to co-locate with requires a lot of due diligence even before approaching the other organization.

“There are some common sense things like making sure the other group is solvent,” says Kent Richards, executive director of the Society of Biblical Literature, which co-located with the American Academy of Religion. “Are your cultures similar? Are you about the same size because if one group is significantly larger than the other, it won’t work.”

Oracle Software suggested that three of its user groups, including Oracle Applications Users Group, co-locate to save money and share ideas. Thus, Collaborate: Technology and Applications Forum for the Oracle Community was born. At is recent meeting, the three groups attracted 5,500 attendees and held more than 800 education sessions.

Christine Hilgert, CMP, vice president of Atlanta-based Meetings Expectations, works on the co-located meetings for Oracle Applications Users Group.

When Oracle first suggested co-locating, Hilgert says the members were hesitant — if not downright hostile — to the idea. After much debate, she said the decision ultimately came down to whether or not it was a good idea. “Do the members want this to happen? Go out and get a clear message from them in the beginning before you go too far. Get the membership buy-in and then go forward.”

So, you’ve done your due diligence and it makes sense to co-locate, what’s the next step?

Just as you might with the families back in the vacation rental, some rules are in order. After a rocky first-year experience, Hilgert and the other two Oracle groups worked up a 30-page Memo of Understanding. “It documents, well, everything,” she explains. “It spells out how we will market, split the revenues, all the way up to how we will resolve a conflict among the organizations. Each year we tweak it a bit. But [we] don’t go into co-locating loosely and think we’ll figure it out.”

Eisenstodt also is a firm believer in putting agreements in writing. “You need to really get into every detail. Who gets the comp rooms and how many? Who handles registration? How are you dividing the money and the expenses? You must cover all contingencies such as what happens if a group backs out or doesn’t meet its attendance projections. Liability issues are huge. [The agreement] also needs to be approved by the executives, including the CFO.”

Basically, it seems that problems come under two basic categories: retaining identity and money.

“Initially, our members didn’t like us co-locating, there was resistance,” Hilgert admitted. “It was a board of directors decision. The problem was: How do we ensure that our membership gets the benefits from our organization and have them know it’s coming from us not them. I’ll admit there was a lot of shows of strength and posturing on our side — and theirs as well.”

Some of the problems that Hilgert’s Oracle group faced involved maintaining their separate identify within the exhibit. For instance, her group always had electric signs but the other two preferred lower-cost paper signage. “We went with electric and the other two went with paper and then next year cost became more of an issue for us. We began to let our guard down and trust each other,” she says. “And, frankly it turned out that having different signage confused our attendees.”

Those same attendees might also have been confused by the carpet the first year as well. One group insisted the color of the floor match its logo. The other two user groups didn’t care if the carpeting matched the third’s logo. They opted for different carpeting.

Naming the show and logos also were topics of contention. “We didn’t want to give up our organization’s identity,” Richards says. “When you’re planning to co-locate, things like the name are more than symbolic.”

For instance, Richards’ event is “hosted” by the co-locating organizations, and after much hassling, it was decided not to name or brand the event. “That was a big problem. Our organization had the stronger name, and we felt it should be our name,” Richards says. “In the end, we just let it be the date and city. Next year it’s called 2011: San Francisco. It’s not great, but at least it’s a solution.”

Other issues involved where the organizations’ ads were placed in the program (it changed daily).

The second area of problems comes under the big tent called money. “It’s going to be complicated,” Warner admitted. “It’s never 50-50.”

Hilgert said that all three groups sign all contracts together and negotiate things such as rates together. They came up with a solution on how to split revenue generators such as exhibitors, that’s based on what percentage each group has in the exhibit hall. “All three of us do a lot of business with IBM,” she says. “So who manages that account and money? We decided that if my group has 40 percent of the floor, then we get 40 percent of the revenue and pay 40 percent of the costs.”

Reaching that decision saved a lot of staff work trying to document and figure out who gets and pays what. But she is quick to add that sponsorships do not fall into that ratio solution and are handled differently.

Warner’s partners came up with a similar solution but it is more based on percentage of attendance, so if his group has 15 percent more attendees then costs and revenue reflect that 15 percent.

“It really becomes much harder making decisions because you are dealing with a committee and everyone has an opinion on something, especially when it involves money,” Warner says. “I remember spending hours discussing what to charge for the luncheon. We said $20 and the other group insisted on $25. I remember being furious thinking that I was wasting an hour arguing over $5.”

Still, those who have co-located said that it can be done successfully as long as the staff works together and tries to work out every contingency together.

“There are just so many details but I think the staff worked together better than anyone imagined,” Richards says. “But the thing to remember is that while the staff works well, political matters outside of the staff do matter and it can erupt into divisiveness.”

In fact, Hilgert says that after the first year of defending turf, the staff realized that their constituents were not that interested in what they were battling over. “After fighting over signage, logos, you name it, we realized that things got better when we thought about what our members wanted as opposed to what we wanted.”

Eisenstodt believes co-locations offer many benefits both to the organizations and attendees. “Just make sure you know what is shared and what is separate and who’s in charge of what,” she explains. “The more details that you determine ahead of time — every little thing, such as where the logos will be placed on the badges — will help it all fall into place, and everyone will benefit.”

With planning and follow-through your co-location experience won’t become one of those horror stories from vacations past.