LOS GATOS, CA -- Local and federal fire investigators in this upscale hamlet are investigating the role construction built without permits may have played in a fire that took the life of a newly promoted captain -- the first firefighter to die in the line of duty in the 58-year history of the Santa Clara County Fire Department.

It's illegal to build or perform most home improvements without a building permit and while the exact cause of the fire and the firefighter's death is under investigation, county building officials declared the home unsafe and dangerous.

The senior county building inspector served notice on Valentine's Day ordering the home owner to obtain a permit and begin to repair or demolish what's left of the home within 20 days and complete the work in 180 days. If the work is not completed on schedule, the county's order threatens legal action including seizing the property for upgrades and placing a lien on the property for the cost of the work.

The fire started in the same general second story sun room area as a previous fire in 2003 and a previous owner was cited in 1986 for performing work without a permit.

Even if illegal construction didn't play a role in the firefighter's death or the fire itself, the fire is a stark reminder of what happens when, by whatever means, illegal construction is discovered.

You must obtain a permit for most home improvements -- do-it-yourself jobs or work that's hired out -- because the permit process triggers building code compliance requirements.

Building codes are a minimum set of standards for the design, materials, and building techniques created specifically to protect the health and safety of anyone occupying buildings. Depending upon the jurisdiction, permits are required for something as simple as installing a dimmer light switch or water heater installation, to constructing a 3,000 square-foot-home.

Home owners typically fall back on penny-wise-and-pound-foolish bottom-line reckoning when they want to justify circumventing the legal permit process.

The remodeling boom in every corner of the nation has created a backlog in some building and permit offices and time is money.

The demand allows professional home improvement companies, architects, and related professionals to charge more for their work.

Permits themselves can cost hundreds of dollars and the paperwork begins a record-keeping process that can result in a higher assessed property value that could mean increased property taxes.

Misguided penny pinching, however, overlooks the fact that any immediate savings realized by skirting the law could end up costing much more, and bring on some long term liabilities.

Generally, to obtain a permit, you must submit a building plan or, for smaller projects, a description of the work to be done.

Provided the plan complies with the codes, the building department issues a permit, for a fee. That triggers one or more inspections of the work in progress or upon completion or both. Building inspectors give the job the once over to make sure the job complies with building codes and that you are using the proper materials and building techniques.

Beyond the benefits of code-complying building practices, a compelling reason to obtain a permit is the cost of not obtaining one. And all it takes to trigger that cost is for the building department to discover illegal work.

Limited and sometimes poorly handled record keeping in some building departments could prevent anyone from ever discovering you've worked on your home without the proper permits. Also, building officials certainly don't foot-patrol neighborhoods looking for violators.

But along with fires, floods, earthquakes, and other disasters that prompt a building inspector to come calling, there are a host of other events that will keep your illegal construction from going unnoticed.

Let's say a savvy home buyer hires a home inspector to examine the condition of the house you are selling. The buyer's inspector uncovers home improvement work and, to protect the buyer's investment, he or she seeks the home's permit record. Each permit typically includes the address of the building, the contractor, the type of work being done, square footage, inspection dates, and status of the work. If the proper permits aren't in place, that could kill the deal.

Later in the transaction, an appraiser may also seek permit records to learn if significant renovations should affect the value of a home.

Appraisers say in some regions the lack of permits turns up in 20 to 25 percent of homes appraised. Illegal work can stop an escrow cold.

Also, you and your agent typically are legally required by law to disclose any known conditions that could affect the value or salability of a home listed for sale. If the buyer thinks he or she can prove you knew about the illegal work, but didn't disclose it, you could get sued.

If, after close of escrow, the buyer discovers work completed without a permit and the local building department decides not to approve the work, a chunk of the home's value could become a legal issue. Any difference in value based on illegal work can become a point of litigation.

In another scenario, during a building official's scheduled inspection of a perfectly legitimate home improvement, he or she could also turn up older illegal work. The building department could then "red tag" the job and issue a stop-work order.

If an inspector suspects illegal work, you could have to pay for the cost of any inspections required to make a further determination. You could have to remove dirt along the foundation so it can be checked or you may have to tear down sheet rock inside so the inspector can look at framing, insulation, wiring, and plumbing.

If the work is deemed illegal, you must legalize the work before you can sell the home and, again, that also could mean tearing out old work.

If the illegal handiwork is yours, costs can continue to mount. The building department could levy higher punitive permit fees as well as fines.

In any event, before you can obtain a legal permit on old work, you'll have to hire an architect, engineer or other professional to help draw up plans for permit approval.

Even if unpermitted work complies with current building codes, building departments often issue only a statement of compliance -- not a permit. Because the statement applies only to the visible work, a lender or buyer may not be satisfied and demand that you obtain a permit.

Again, that could mean tearing out the work and rebuilding with a permit -- which is what should have been done in the first place.