Section 4. The housing board may make, and from time to time amend, reasonable rules and regulations in regard to the procedure for securing the approval of projects under this chapter and for the financing, construction, management and maintenance of such projects. The housing board may, for the guidance of the proponents of a project, fix general standards to which the plans of such a project shall conform. Variations from such standards may be allowed for the accomplishment of the purposes of this chapter. Such standards may contain provisions more restrictive than those imposed by applicable planning, zoning, health and building laws, ordinances, by-laws and regulations.