Conn. Gen. Stat. § 25-88: Method of assessment.

Whenever any assessment is made as herein provided, the amount to be raised thereby shall be apportioned among the properties benefited according to such rule as the board may adopt, based upon area, street frontage, assessed valuation of the land in the last-completed grand list of the municipality, the present or permitted use of any real property in the section, or any combination of these or other relevant factors. The board may make reasonable allowances when for any reason the particular condition or situation of any property requires such allowance. No benefits shall be assessed against any property in excess of the special benefit to accrue to such property. Assessments under this part shall be made subject to the provisions of sections 7-139 to 7-145, inclusive.