The plans for Tom and Leigh Glenn's $350,000 Catalina Foothills home are clear. The proposed metal building was approved by Pima County in Arizona.

The blueprints show two small bedrooms, a kitchen, a bathroom and a 6,000-square-foot "hobby room." No one questioned the size of the hobby room when the Glenns submitted their building plans. But eight months and $100,000 into building the house, the s chief zoning inspector decided that was too much hobby for one house.

Indeed, she questioned whether it really was a house at all.

"It is my determination that the primary use of the property is clearly for 'hobby' and not for 'single-family residence' " Chief Zoning Inspector Pat Thomas wrote in a letter revoking the Glenns' building permit in November 2006 and ordering them to stop.

The Glenns lost an appeal to the Board of Adjustment and now are suing the county, seeking the restoration of their building permit and attorney's fees. The Arizona Daily Star had the report.

"We believe the law says that if you follow all the rules and spend all the money associated with following the process of getting a building permit, your right to that building permit becomes vested," said Patrick Lopez, the Glenns' attorney. "They can't take it away."

County Development Services Director Carmine DeBonis said the county took a second look at the plans when neighbors started asking questions and decided the structure wasn't appropriate after all.

Three years ago, the Glenns bought a former Tucson Electric Power substation that borders their existing home. They said they planned to use the 8-foot-high brick walls surrounding the substation as the base for a steel building that would be a home for their two teenage sons when they entered college, and provide storage for all manner of vehicles, from dune buggies to quads to motor homes.

Tom Glenn says he likes to tinker "as much as any man" and wants a place to store his vehicles away from the elements and the pack rats. His sons could have their independence without being too far away, and perhaps when he and his wife are older and no longer want to maintain a large home, they could move into the 1,200-square-foot living quarters.

He decided to construct a steel building because he works in the general steel building industry. It may not be to everyone's taste, but it is an allowed building material in Pima County.

Glenn submitted his plans in March 2005. He completed engineering studies and native-plant studies and erosion setback analysis and received a building permit — which cost an additional $12,000 in fees — in March 2006.

"We haven't hidden anything," Glenn said. "We're building exactly what we show on the plans."

When the Glenns started construction — pouring a 2-foot-thick slab, bringing in electrical lines and plumbing — neighbors became increasingly concerned by what looked to them like an industrial, commercial metal building. They pulled the plans and became more concerned.

Thomas, who responds to complaints but generally doesn't review plans before permits are issued, took a look at the plans, and what she saw didn't look like a single-family residence to her. In a memo defending her decision, Thomas wrote that when the nonresidential use of the building is so out of proportion with the residential use it raises questions about which actually is the primary use.

The zoning code doesn't say anything about how large one room in a house can be compared with other rooms, much less what zone hobbies are allowed in.

"If you have a 3,000-square-foot living area and you have another 10,000 square feet of basketball court or indoor swimming pool, that doesn't convert the home into an athletic club," Lopez told the Board of Adjustment. "It's still a single-family residence with an area designated for a purpose you enjoy."

In letters to the county, neighbors said they believe the Glenns really plan to run a commercial recreational-vehicle repair shop out of the building, but they also raise concerns about the appearance of the supposed metal storage building, essentially a large steel rectangle.

For now, those letters have been enough ammunition to halt the steel building project.