Conn. Gen. Stat. § 8-1c

(b) A municipality may, by regulation, require any person applying to a municipal zoning commission, planning commission, combined planning and zoning commission, zoning board of appeals or inland wetlands commission for approval of an application to pay the cost of reasonable fees associated with any necessary review by consultants with expertise in land use of any particular technical aspect of such application, such as regarding traffic or stormwater, for the benefit of such commission or board. Any such fees shall be accounted for separately from other funds of such commission or board and shall be used only for expenses associated with the technical review by consultants who are not salaried employees of the municipality or such commission or board. Any amount of the fee remaining after payment of all expenses for such technical review, including any interest accrued, shall be returned to the applicant not later than forty-five days after the completion of the technical review.

(c) No municipality may adopt a schedule of fees under subsection (a) of this section that results in higher fees for (1) development projects built using the provisions of section 8-30g , or (2) residential buildings containing four or more dwelling units, than for other residential dwellings, including, but not limited to, higher fees per dwelling unit, per square footage or per unit of construction cost.

Town has broad authority under section to define subdivision application processing fees by ordinance subject only to the standard of reasonableness. 232 C. 44.