Number of inclusionary units. Any proposed residential development containing five or more dwelling units is required to include at least 20% of the total number of dwelling units within the proposed development as affordable units. The inclusionary units must be affordable for a minimum of 99 years through a deed restriction or through being held in a community land trust. The Town of Lincoln prefers that inclusionary units be built on site. However, developers who satisfactorily demonstrate to the Planning Board that building the inclusionary units on site is infeasible may request to make a payment in-lieu-of fee or to build the inclusionary units off site. The Town, at the applicant's expense, may have an independent real estate consultant determine feasibility of building the inclusionary units on site. Developers must round up to the next highest number for fractional units. As an alternative, an in-lieu-of fee may be paid for the fractional unit. The amount of the in-lieu-of fee will be in direct proportion to the percentage (out to two decimal places) of a single unit that is represented by the fractional remainder of the above inclusionary unit calculation.