If the washer is adjacent to an exterior wall you'll have less chances of vibration than you would if the washer is against an interior wall. That's because exterior walls are usually more rigid than interior walls because they have to support the weight of the roof and floors. Locating the washer in a corner with two exterior walls is even better.

If your house is still in the framing stage, ask the contractor to provide extra bracing in the floor to ensure that it's as rigid as possible. If it's too late for that, and you later find you're having a vibration problem, the floor can be strengthened by laying a 3/4" thick piece of plywood, large enough to support the washer on the floor, and screw it into the floor joists with long screws at 6"-9" intervals. That will provide you with a very rigid floor under the washer.

If you're even moderately handy, I recommend installing the washer yourself, in exact accordance with the manufacturer's installation instructions. It's not difficult, just a bit tedious employing the "trial and error" method of ensuring that you've got the leveling feet adjusted properly. You're likely to spend as much time as necessary to get it right, a professional installer may not want to spend the time it takes to get the machine optimally level and flat on the floor. It is vital that the machine be properly leveled and the weight of the machine is evenly distributed to all four feet.

If you're unwilling or unable to do the installation yourself, be sure to get a guarantee of satisfaction from whomever you engage to do the installation. If possible, don't pay for the installation until after the machine is installed and you've ascertained that vibration isn't a problem.

One other thing, be sure to specify that the shipping struts (or bolts, as the case may be) are not removed from the washer until after the machine is moved up your stairs. Bouncing up a stair on a dolly with the struts (or bolts) removed, will cause damage to the suspension. Delivery people always want to remove the struts while the washer is still on the truck. Don't let them, and insist that they leave the struts with you, so they can be reinstalled if you ever need to move the machine.

Buy from a place which gives their installers enough time to deal with any complications. Unlike, say, Sears when my machine was delivered last year. When it was well past the delivery window and they hadn't shown up yet, I called the contact number. Was told they'd arrive soon, and, by the way, I was their 20th and last stop of the day. When the crew showed up around 6 PM, the driver confirmed that, yes, I was their 20th stop, and they'd been on the road since, IIRC, 6 AM. Well, my installation went fine, because they knew their jobs well, and there were no complications. But they sure didn't have time to deal with any irregularities, or to do anything but the most minimal testing. The paperwork didn't say Sears, rather the name of a third-party delivery company.

I ended up returning the machine a few days later, for reasons unrelated to the installation. Having gotten the shipping bolts from the crew upon delivery, I was careful to leave them on top of the machine for the pickup crew. But they didn't reinsert the bolts, rather they tossed them into the drum and took the machine.

I don't see how you can expect the installers to guarantee that your house is constructed to eliminate vibration! I would look for a vendor who will let you return it in a reasonable time frame if there's a vibration problem. Be upfront with them. Tell them what you have and your concern about it and make them put it in writing if they will let you return it if vibration is an issue. Otherwise you might be limited on the machine you get.

Having the floor reinforced ahead of time is a good way to go. Sometimes the vibration absorbing mats can be helpful too.

BTW, most any bigbox store will utilize 3rd party installers and you never know if they know what they're doing or not. You can also check the FAQs for some tips on installation.

Thanks everyone. We close in a few weeks and so we can't ask for the floor to be reinforced and unfortunately the laundry room wall is an interior wall so that's not anything I can control. So construction things aside I just wanted to maximize our chances the washer is properly installed. DH is handy so we could possibly have him do it, but maybe we'll just adjust if needed. I will also follow the recommendations to a) no have the shipping bolts removed until it's upstairs b) keeping the bolts (a good tip I've seen around this forum) and c) asking for a guarantee of satisfaction for the installation. I also think we'll buy from a smaller local store where we are also getting our fridge so I hope that will eliminate the issue of 3rd party installers with tons of jobs on one day.

One last question - once it's installed what is the best way to test balance? Run and empty load or do I need to have laundry in the machine to be sure? Thanks!

The empty drum is perfectly balanced, hopefully, so spinning it won't prove anything. For a real wash, the severity of vibration depends on what's in the load, how it gets distributed during the cycle, and how the machine's balancing algorithms react to it. So, if there's no problem with a couple of real loads after installation, you can start to relax...but you can't be sure until you've used it for a while, and done all kinds of loads.

Thanks suburbanmd. Obviously I'm exposing my ignorance here, so I sure do appreciate all the help!