Updated Sunday, December 30, 2012 at 11:31 PM
The three-story house, with dormers, wood siding and expansive windows, looks like it belongs in a new subdivision on the Eastside.
But it was designed by a naval architect, built on a floating steel hull and framed by a former boat builder who says it's a legal vessel.
Located on a Lake Union dock beneath the Aurora Bridge, the floating house is Example A of the city's difficulty in drafting new regulations for residences over water as it completes its state-required update of the Shoreline Management Act.
The city's attempts to define a vessel so it clearly excludes big new floating houses have stirred up angry opposition among some dock owners and residents of existing houseboats and house barges, which could become illegal under the new rules.
The city banned new floating homes in 1990. An estimated 490 that are connected to the city sewer system and permanently moored at city-approved docks would remain legal.
Thirty-four house barges not connected to the sewer system were grandfathered into city code in 1992 and would remain legal, but the city would enforce requirements that owners capture their gray water, the runoff from sinks and showers.
The city has done little enforcement, with the result that floating residences have multiplied at marinas and docks. Officials estimate that there are now about 150 floating residences that the proposed changes could leave in legal limbo.
"We'd like to find a path forward that doesn't effectively take away people's homes," said Councilmember Mike O'Brien.
But he also thinks the rules need to make clear that new giant floating houses claiming to be vessels aren't legal.
"We weren't going to put any more houses on the water. If you ask people whether some of these are a house or a boat, most people would say it's a house," O'Brien said.
Councilmember Richard Conlin, who chairs the Planning, Land Use and Sustainability Committee, said the council may approve the shoreline regulations, but set aside the thorny issues about floating residences. Instead, the council would seek an administrative solution such as a city certification or licensing program.
Some council members have said they want to protect the quintessentially Seattle lifestyle of houseboats. This fall they proposed an amnesty program for all current liveaboard structures and vessels.
But the state Department of Ecology, which approves and enforces city shoreline-management plans, ruled out blanket amnesty earlier this month.
Under state law, priority is given to water-dependent businesses and industries, shoreline restoration and public access. Residences over water aren't a priority use.
"When we look at state guidelines, we don't see how an amnesty provision could be allowed," said Joe Burcar, senior shoreline planner for Ecology.
Some of the questionable Seattle houseboats and barges are tiny, with less than 600 square feet of living space and a relatively small ecological footprint.
But some owners, like Mike Sherlock, have built grand residences to Coast Guard standards and argue that the city can't regulate them because under city law, it's legal to live on a vessel.
"I know it looks like a house," said Sherlock, who operated a boatyard for 25 years. "I could have retrofitted a ferry, I could have built on a barge. I could have bought a big yacht. Those are all legal."
Sherlock wouldn't give the total square footage of his floating residence, saying only, "It's comfortable."
But earlier this month the city slapped Sherlock with a notice of violation for his house and two others on the same dock. The City Attorney's Office now is prosecuting another owner who strapped running lights and a big outboard motor onto a large floating residence in an effort to argue that it also was a legal vessel.
"They don't meet what we think of as the requirements of a vessel," said Faith Lumsden, code compliance director in the Department of Planning and Development.
She said that houses require building permits and must comply with shoreline regulations.
"These structures appear to be residences," she said.
But some dock and houseboat owners are angry at the city's attempts to regulate them.
"The city has no ... reason to have rules," said Suzie Burke, a Fremont businesswoman who owns the dock where Sherlock has his floating house moored.
"People have been living on vessels on the (Lake Washington) Ship Canal and Lake Union since before Seattle was a city. If the city does this, they're going to have a major lawsuit."
Burke said the owners of floating residences pump their sewage and use biodegradable soap for dishes and bathing. She said the effluent is a fraction of what washes off city streets into lakes and Puget Sound each year.
But Conlin said a majority of the public wants the city's shorelines preserved for recreational and water-dependent uses.
"A huge contingent of people don't want to see private people taking over public space," he said.
In its attempts to update the rules regulating shoreline uses and development, the city has struggled with trying to define a vessel to exclude what it thinks is a house.
The Department of Planning and Development hired a naval engineer for $10,000 to try to better define a vessel. He came up with a formula that included hull-length-to-beam ratio, sail-area-to-hull-plan ratio and requirements for self-propulsion and design.
But the proposed standards were so complicated the City Council scrapped them earlier this month and instead has proposed describing what's legal as a "conventional recreational and commercial vessel." That definition includes cabin cruisers, sailboats, tugboats and sports boats but excludes more boxy houseboats.
One resident of a boxy houseboat supports an administrative solution to the problem. Mauri Shuler, a member of the Lake Union Liveaboard Association, said an over-water residence could be certified by an accredited marine surveyor as having propulsion, safety equipment, steering and navigation lights and get city approval as a vessel.
Another option would be for the city to create a legal houseboat category, she said. Owners would have to agree to pump their sewage, use biodegradable soaps and other "best management practices" to protect water quality.
Sherlock supports granting amnesty to all the floating structures in the city, then enforcing the new regulations so that no more would be built.
"I don't feel I'm in the wrong. I care about the lake. I care about the people around me. I care about Seattle. I want to live here forever, and I built my house so I could."
Lynn Thompson: 206-464-8305 or email@example.com. On Twitter @lthompsontimes.
This house, built by Mike Sherlock, sits beneath the Aurora Bridge on the north side of Lake Union in the Fremont neighborhood.
GREG GILBERT / THE SEATTLE TIMES
The three-story house on a Lake Union dock has dormers, wood siding and expansive windows. It was designed by a naval architect, built on a floating steel hull and framed by a former boat builder who says it's a legal vessel.