When Bryan Norrington has new renters sign a roommate agreement promising ­—among other things — to keep the place neat and clean, it’s nothing personal. It’s about avoiding drama in the long run.

“In my experience with roommates, I’ve realized that there’s a certain level of cleanliness that I like to have in the common space,” says Norrington, 30, an economist who owns a four-bedroom house in Fort Totten and rents out two of the rooms.

When living with roommates, apartment cleaning can become a battlefield. For some, tidying up is second nature, while others take to heart

Phyllis Diller’s famous quote: “Housework can’t kill you, but why take a chance?”

While it can be a challenge for a neat freak to room with a clutterbug, here are a few tips for keeping things neat to keep the peace.

Set ground rules

Renters might save themselves some conflict by screening for a good housekeeping fit on such websites as Roommates.com, Easyroommate.com and Roomiematch.com.

New or potential roommates should have a conversation upfront to figure out which areas they expect will be clean. In Norrington’s case, his roommate agreement covers common areas, but bedrooms are off-limits.

“What you do with your space is fine as long as smells don’t start seeping out or we don’t have rodents,” he says. “What you do in your room is your business.”

Get outside perspectives from people you don’t live with on what they consider deal-breakers — be it hair in the sink or piles of unopened mail — and see if you would, too. There might be things you never realized.

“Then you can have a discussion,” he says. “People can be honest and say, ‘Yes, I’m capable of doing X and not Y,’ and you can either compromise or decide it’s not the best idea to live together.”

Call in the experts

Before dietitian Maggie Sommers, 30, moved into a one-bedroom rental in Foggy Bottom with her fiance, she turned to outside experts to solve any neatness issues before they started. Consultants from Neat Method (855-232-6328), a home organization company, helped with the move and set up an organization system in their new place from Day 1.

“I’m so crazy-organized,” Sommers says. “You never want to start off on the wrong foot.”

The company created logical plans for where to put things, bought gear from the Container Store, and walked the renters through the new system.

“It’s been all stuff we’ve been able to keep up with,” Sommers says. “You save yourself a bunch of silly fights.”

Marissa Hagmeyer, director of marketing for Neat Method, says most of their clients are couples in which one person is much more organized than the other.

“That’s a great time to call in a third party,” she says. “It’s someone else correcting and giving advice.”

In the end, the less organized person gets as much peace from the living situation as the super neat one, Hagmeyer says. A typical job in D.C. costs between $300 and $5,000, depending on the number of rooms, size of the home and amount of clutter.

Hiring cleaners — which can cost upward of $60 for two hours — can help, too, though Hagmeyer points out that a clean but disorganized house might still look like a mess.

Norrington and his roommates split the cost of a biweekly service to sweep and dust and clean the bathrooms.

This way, Norrington knows the cleaning isn’t just lip service. “Somebody may just take a paper towel and wipe something and say, ‘I cleaned the bathroom,’ ” he says.

Choose your battles

If it’s too late to screen your roommate, or if your roommate happens to be your significant other, be careful how you approach cleanliness conversations, says couples therapist Keith Clemson. A softer approach will always win out over a critical one, and make the other person more willing to compromise.

“There are ways to do it and ways not to do it,” says Clemson of Therapy Group of DC (202-601-3368). “Just say, ‘We differ on this, and your way isn’t wrong and my way isn’t wrong.’ ”

Norrington says it’s also important to choose your battles. “There are some things that aren’t that big a deal and there are others that are extremely important to you,” Norrington says. “Those are the ones you find a diplomatic way to communicate.”

Odd Couples 101

Whether you’re the neat roommate or the messy one, try these tips from Marissa Hagmeyer of home organization company Neat Method to keep the peace in your place.

Make sure everything has a home, and everyone knows where those spots are.

Keep everyday items close to the dishwasher and keep similar items close together.

Set a regular time to go through a space, say every other week or once a month, and get things in order.

Create organization systems that work for both of you. E.B.

Passive aggressives’ guide to handling messy roommates*

Post a rigorous weekly cleaning schedule on the fridge without discussion and hand your roommate a broom as soon as he or she comes home from work.

Complain to the landlord that your roommate never makes the bed.

Close your roommate’s door whenever he or she leaves it open, and hang a sign on it that reads “hazardous waste.”

Dust the TV while his or her favorite show is on.

*To actually change your roommate, do the exact opposite.

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