WHEN her teenage nephew moved in, Shirley Miller shuttled her home office from a spare bedroom to the dining room of her Sherman Oaks house.
It wasn't ideal, not with her own teenage son still living at home. But adding onto the 1,500-square-foot house would have cost $110,000 to $130,000, so she did what a growing number of squeezed homeowners are doing: She bought a kit for a pint-sized cottage and erected it in the backyard.
Now she strolls across the grass and opens the French doors into her 12-foot-by-16-foot office, where she writes training programs for businesses. The gray exterior, trimmed in white, blends with her home. Inside, white furniture offsets the sky blue walls.
Miller and others are redefining the common backyard shed. Once shabby, now showy, the shed has become a haven for the home office, art studio, sewing niche or guy getaway.
It's cheaper than adding on, goes up faster and looks nothing like a place to stash the lawn mower. The sheds come in a variety of styles -- rustic, urban modern, dollhouse -- and some owners add comfy features such as air conditioning, sky lights, custom windows and doors, everything but plumbing.
Miller is happy with her backyard retreat, though the $12,000 kit she bought from Summerwood Products last fall ballooned into a $25,000 project by the time she was done.
And she hit some bumps along the way -- pitfalls that others might heed.
Her kit arrived in a big box with sections pre-assembled by Summerwood, a Toronto company that uses Canadian cedar. She hired a contractor to lay a concrete foundation and put it all together for $10,000.
"It was reasonably easy to build," Miller said.
All was well, until a Los Angeles building inspector knocked on her door one day. "I had it built without permits," said Miller, still in the dark about who reported her. Though it was built to code, accessory buildings larger than 64 square feet need a building permit in the city.
"I had to retroactively get permits," she said. "It was not a fun experience."
The additional engineering drawings and permit process added $3,700 and four months to the project. The permit process caused her to go over budget and she had to finish off the interior herself.
"After all the gnashing of teeth, now I'm happy," she said. "It's nice looking. It doesn't look cheesy."
Homeowners don't have to spend as much as Miller did, though they may sacrifice on the quality of the wood, the look and other amenities such as glass doors.
Costco sells kits in the $2,000 to $3,000 range. Home Depot sells Tuff Shed structures for about that, including a one-day installation.
A $3,000 barn-style shed from Home Depot, for example, can be turned into a home office for an additional $2,000, if the owner does the insulating, drywalling, tiling and painting. Even handier types can buy a set of building plans and do it all themselves or hire a contractor.
Dan Gray built a shed about 10 years ago and has been dispensing tips ever since, morphing his passion into www .geekbooks.com eight years ago. Based in New Jersey, where he writes computer how-to books, Gray has seen a rising interest in the backyard retreat.
"It's folks running out of space," he said. "They need a place to work that's quiet, away from the house." California's mild climate makes the shed a good solution.
First, check with the city
He recommends a trip to the city's building department first to see what permits are required. Many places in the state allow backyard structures of up to 120 square feet without a building permit, but some cities are more restrictive and have differing setbacks and height limits. Also, a permit for electrical wiring is probably necessary.
Gray's other suggestions:
* Go with real wood, not plastic, steel or chipboard. "Cedar is an excellent choice."
* Build it big enough. "You'll never want a smaller shed. . . . Go as high as you can; the extra space overhead is valuable for storage."
* If you leave the interior unfinished, you'll gain some shelving space.
* Make sure there is proper ventilation and that the windows can open and shut. Some prefab sheds and kits are insulated and finished on the inside; others aren't.
* Siting is important. "You want to take advantage of the natural light without roasting." And take drainage into consideration. It will be easier to keep dry and stave off rot if the structure isn't located where water collects after a rain.
As for foundations, many companies say they aren't needed. The buildings can rest on level gravel, patio stones, cinder blocks or concrete footings. Tuff Shed uses a steel floor joist system that the shed sits on.
Foundations help distribute the weight of the shed evenly to prevent warping and windows and doors that don't work. "But they can cost the owner a chunk of change," Gray said.
Steven McKee of S.P. McKee Design & Construction in Newbury Park pegs the cost of a slab for a 120-square-foot shed from $800 to $3,000, depending on the slope of the land, geographic area and contractor.