The 20-year line
Title 17 sorts the work by design life. A treatment designed to last 20 years or more is abatement: certified Supervisors and Workers, plus a written plan. A shorter-lived one is an interim control that needs no CDPH certification, though containment, no visible dust and the other Title 17 rules still apply. Settle which side your job falls on before the quote, since it depends on product and design.
Notice and clearance
Permanent abatement means Form 8551, posted and delivered five days ahead, then a clearance inspection. Keep the paperwork: a later buyer or tenant may ask what was sealed, where and when.
What affects the cost
Area treated, paint condition, the product chosen, whether a surface must be boxed in, access, and the inspection and clearance steps define the scope. Sealing a few trim pieces and sealing a floor’s worth of walls are different jobs.
Sealing is a decision about paint that stays in the house, so confirm the lead first with the testing described on lead paint inspection and testing. If the trouble is outside and the paint is already failing, that points to exterior lead paint removal. The Novato Lead Paint Removal start page leads to everything else, including the remodel and window services.