Section 6-620. Sidewalks, payment for construction

Whenever the owner or
  occupant of lands adjoining a street  constructs  along  such  street  a
  sidewalk  of  stone,  cement,  brick  or  other  similar materials to be
  approved by the board of trustees, and the  board  consents  to  bear  a
  portion  of  the  expense of construction thereof, the board of trustees
  may pay to such owner or occupant a sum to be  fixed  by  the  board  of
  trustees  not  exceeding one-half of the actual and necessary expense of
  constructing such sidewalk.  Before  the  board  of  trustees  shall  so
  consent  to  bear  a  portion of the expense of construction of any such
  sidewalk, it shall fix the proportionate amount that shall  be  paid  by
  the  village  for  all walks of the same kind which may thereafter, with
  such consent, be constructed therein; and such proportionate amount  may
  be changed from time to time thereafter by the board of trustees, but at
  no  time  within  one  year from the date of the last fixing or changing
  thereof.