If you're looking to spruce up your office, there are endless experts who are more than willing to weigh in on what the space should look like. From professional designers to creativity researchers, tons of professionals have (often high-priced) opinions about the ideal office.

But according to a new study from two psychologists at Britain's University of Exeter, your best bet might be simpler and cheaper than that. While you'll always need to invest in the basics of space, furniture, and fittings, this research suggests the best arrangement for these is ... whatever your own people come up with.

The best decoration is self-determination

As explained on the TED Ideas blog by economist and author Tim Harford, the study compared volunteers' productivity on a routine task in a variety of spaces. First to be compared were a minimalist office and one with more amenities like potted plants and large prints. As you'd probably expect, people got more done when they weren't forced to stare at bare walls, and this finding that more humane spaces improve productivity is backed by other research as well.

But that's not the most interesting bit. The research team also tested two other types of offices--one in which the subjects were given a few minutes to arrange the furniture and decorations to their own liking (this was dubbed "the empowered office") and one slightly sadistic space where they were allowed to redecorate and then forced to watch while the researchers put everything back the way it originally was ("the disempowered office").

No bonus points for guessing that the final condition was an infuriating productivity suck--"I wanted to hit you," one participant apparently told the experimenter--but more surprising may be the size of the bump in output created by working in the personalized space:

"The empowered office was a great success--people got 30 percent more done there than in the lean office, and about 15 percent more than in the enriched office [the one decorated by the researchers with plants, etc.]," writes Harford. "These are large effects; three people in empowered offices achieved almost as much as four people in lean offices."

Control freak tendencies or design snobbishness will cost you

That's important news for bosses--you could pay three people working in a space where people exercise some control over their surroundings, or four and enjoy design-magazine-ready minimalist splendor. Which would you choose?

Not only will your people get more done in a humane space, but they'll also be happier, and that is likely to have significant, positive knock-on effects for your business. When quizzed later by the researchers, participants said they hated the minimalist and disempowered spaces, but their negative feelings extended way past the environment.

"Their feelings of despair became all embracing: If they disliked the office space, they also disliked the company that was hosting it, and they disliked the task they were doing in it," Harford explains.

The bottom line: "The best option was to let workers design their own space," writes Harford. "The very worst was to give them the promise of autonomy, and then whisk it away." That holds even if you're limiting their self-expression in the name of tidiness or good design.

Do you allow your people to put their own stamp on their workspaces?