Thanks to telecommuting, layoffs, and an increasing number of free-spirited freelancers, 11/2 million couples now work together full time from home, according to IDC, a Massachusetts-based research firm. Some spouses in Washington work from home after long days at the office.

Architect Robert Gurney says he's turning lots of dens and bedrooms into offices, sometimes two to a home. "Five, ten years ago, the office wasn't even part of my projects," Gurney says. "Now it's for him and her, or him and him."

Space constraints force many couples to make do with one office. Problem is they don't always share nicely.

Here are tips for keeping home-office peace:

• Plan for how much workspace can be shared. Can you both use the same side table, or do you need two? Gurney advises overestimating: "When you have two people, you really need some spillover space."

• Separate storage space to avoid mix-ups with files. Some couples have separate office supplies to avoid petty squabbles over Post-its.

• Most people, Gurney says, prefer working "as far apart as they can, and back to back." Maximize elbow room to keep from bumping into each other and remember that sights and sounds can also disrupt.

• Panels or decorative screens can minimize distractions and keep coworkers from checking out what the other is doing. Or not doing.

• Partitions also reduce noise from phone conversations--or an officemate's annoying habit of singing along to his iPod. Soundproofing material on walls helps, but be sure to turn off the beeps on computers and gadgets. One noise-sensitive worker bought his wife new mechanical pencils because her old ones "rattled too much."

• Separate phone lines are a must. Cell phones are one solution, but interference makes them less practical for professional calls. The same is true for cordless phones that run on 900 megahertz--so do many household appliances, which can cause interference. One couple had a "no zapping lunch without asking first" policy after the microwave cut off a big sales call.

• While you'll likely have separate computers, it's easy to share Internet access among two or more computers with DSL, broadband, or wi-fi. Dial-up connections will require extra phone lines and costs.

• Unless they are heavily used, the printer, fax machine, and copier can be shared. Some come as space-saving all-in-one machines.