This chapter does not apply to any of the following works of improvement:
(a) A single-family residence, including a single-family residence located within a subdivision, and any associated fixed work that requires the services of a general engineering contractor as defined in Section 7056 of the Business and Professions Code. As used in this subdivision, “single-family residence” means a real property improvement used or intended to be used as a dwelling unit for one family.
(b) A housing development eligible for a density bonus under Section 65915 of the Government Code.