Cal. Civ. Proc. Code § 337.15
(a) No action may be brought to recover damages from any person, or the surety of a person, who develops real property or performs or furnishes the design, specifications, surveying, planning, supervision, testing, or observation of construction or construction of an improvement to real property more than 10 years after the substantial completion of the development or improvement for any of the following:
(g) The 10-year period specified in subdivision (a) shall commence upon substantial completion of the improvement, but not later than the date of one of the following, whichever first occurs:
(4) One year after termination or cessation of work on the improvement.
The date of substantial completion shall relate specifically to the performance or furnishing design, specifications, surveying, planning, supervision, testing, observation of construction or construction services by each profession or trade rendering services to the improvement.