As an additional and alternative method of financing part or all of the costs of any project undertaken under this act, any municipality may use general tax revenues levied for the purpose or not otherwise earmarked, or the legislative body in its discretion may provide that the cost and expense or any portion thereof shall be assessed to a special district. The special assessment district shall be coterminous with the neighborhood area, and the special assessment district together with the tentative plan of assessment shall be set up as part of the neighborhood betterment plan before acquisition of the property involved in such plan. The written consent of a majority of the owners of property in the special district to the betterment plan shall be submitted to the legislative body. The rate of assessment shall be spread equally, on a front foot or land area basis, throughout the special district.