Cal. Rev. & Tax. Code § 214.13
Where property under development pursuant to the Community Redevelopment Law (Pt. 1 (commencing with Sec. 33000), Div. 24, H.&S.C.) is dedicated to religious, charitable, scientific, or hospital purposes in the redevelopment plan and is required by the plan to be conveyed to the state, a county, a city, or a nonprofit entity entitled to a welfare exemption, that property shall be deemed to be within the exemption provided for in Section 5 of Article XIII of the Constitution of the State of California and this section, and shall be exempt from property tax during construction, provided the title to the property is to be conveyed to the state, a county, a city, or nonprofit agency within three years of the completion of the construction. If that title is not passed to the state, a county, a city, or nonprofit organization entitled to a welfare exemption within three years of the completion of construction, the owner of the property shall be liable for the taxes that would have been imposed, plus a penalty of 25 percent of the amount due.
Ca. Rev. and Tax. Code § 214.13