By LEAH WEATHERSBY

Some might think sidewalks are mostly about pedestrian safety, but many who live in a world without these concrete trails, and the curbs that go with them, face a more daunting issue: where the heck to put the car.

This mainly pertains to those of us who live in North Seattle, north of 85th.

What's more, there's an additional, related problem even for those who eschew personal, motorized transport in favor of buses and bikes: guests of neighbors who decide it's OK to park on your parking strip, which you might consider to be part of your front lawn.

Even if the neighbor's house guests aren't literally driving over your precious grass blades, it doesn't exactly class up the joint.

Following in the footsteps of several of our neighbors, my husband and I decided to add a driveway and fence to the front of our house - hopefully creating attractive physical barriers between the people and car spaces.

But I was confused. I'd been told by Officer John Dittoe, a member of Seattle's community police team, that parking in the front yard is illegal. But what's the difference between a front yard and a driveway in the front of the house? Is it just some concrete and a state of mind?

Not quite, said Alan Oiye, a senior land use planner with the Department of Design, Construction and Land Use. According to the City, the required front yard is the first 20 feet of your property next to the public right-of-way. There are exceptions given if the two houses next door to yours also have short front lawns. In those cases, your front yard must be the average length of those of your two neighbors, Oiye said.

After the required front-yard ends, homeowners are allowed to build up to three uncovered parking spaces on their lot.

In order to access parking, a driveway is needed. That driveway can be in the front of the house provided there isn't paved alley around back.

Here's the kicker: as long as the new front driveway ends in a legal parking spot, you can park cars anywhere in that driveway, including the part within your "front yard," according to Oiye.

Driveways must be at least 10 feet in width, but there are few DCLU restrictions on what they can be made of. They can't, however, be made of grass, Oiye said.

Of course, before you start measuring the distance back to that legal parking spot, you have to figure out where the City right-of-way ends. That, it turns out, is the big and costly question. Those with curbs and sidewalks have it relatively easy - Oiye said Seattle Transportation has a "plan vault" where information on those streets can usually be obtained.

For those with no sidewalks, a professional survey of the property may be unavoidable (though you should check Seattle Transportation records first to avoid unnecessary expense). Where the property lines fall isn't obvious because City right-of-way doesn't end with asphalt - it often extends out to what appears to be lawn.

Of course, the exact cost of a survey depends on the specific characteristics of the property, but it is certainly not cheap. Mark Mauger, a senior project surveyor with Goldsmith and Associates in Bellevue, said a lot survey (where there are no previous surveys to build on) usually runs between $1,500-$1,800, but can go as high as $5,000.

Once you have that right-of-way information, you'll have to go to DCLU and obtain a permit. Cost for that will vary.

But at the price of a survey alone, even the most law-abiding citizen may be tempted to build a cheap, unpermitted driveway and hope for the best.

Fortunately, the second part of the plan - the front fence separating guest cars from fragile grass - is a lot easier. As it turns out, no permit is required. The fence simply has to be six feet or less in height. (The City allows fences to be built up to eight feet tall as long as the last two feet are comprised of lattice, which can be easily seen through.)

Oiye did say that fences that trespass into a City right-of-way may run afoul of Seattle Transportation. The good news is that the City usually only finds out about these from neighbors' complaints. The bad news: fences are one of the things people most often call DCLU to complain about. The best way to avoid the problem, he added, is to line your fence up with what neighbors have already done.

For more information, call 684-8850 or visit DCLU's Web site at www.cityofseattle/dclu/.