(1) In making determinations of "reasonable size," EOHLC will take into consideration both the land area of the Multi-family zoning district, and the Multi-family zoning district's Multi-family unit capacity.

1. (a) Minimum Land Area. A zoning district is a specifically delineated land area with uniform regulations and requirements governing the use of land and the placement, spacing, and size of buildings. For purposes of compliance with M.G.L. c. 40A, § 3A, a Multi family zoning district should be a neighborhood scale district, not a single development site on which the municipality is willing to permit a particular Multi family project. EOHLC will certify compliance with M.G.L. c. 40A, § 3A only if an MBTA community's Multi family zoning district meets the minimum land area applicable to that MBTA community, if any, as set forth in Table 760 CMR 72.12. The minimum land area for each MBTA community has been determined as follows:

   1. 1. In Rapid transit communities, Commuter rail communities, and Adjacent communities, the minimum land area of the Multi family zoning district is 50 acres, or 1.5% of the Developable land in an MBTA community, whichever is less. In certain cases, as set forth in Table 760 CMR 72.12 a smaller minimum land area applies.
   2. 2. In Adjacent small towns, there is no minimum land area. In these communities, the Multi-family zoning district may comprise as many or as few acres as the community determines is appropriate, as long as the district meets the applicable minimum Multi-family unit capacity and the minimum Gross density requirements.
   3. 3. In all cases, at least half of the Multi-family zoning district land areas must comprise contiguous Lots of land. No portion of the district that is less than five contiguous acres land will count toward the minimum size requirement. If the Multi-family unit capacity and Gross density requirements can be achieved in a district of fewer than five acres, then the district must consist entirely of contiguous Lots.

2. (b) Minimum Multi-family Unit Capacity. A reasonably sized Multi-family zoning district must also be able to accommodate a reasonable number of Multi-family housing units As of right. For purposes of determinations of compliance with M.G.L. c. 40A, § 3A, EOHLC will consider a reasonable Multi-family unit capacity for each MBTA community to be a specified percentage of the total number of housing units within the community, with the applicable percentage based on the type of Transit service in the community, as shown on Table 1:

   Table 1.

   Category Percentage of Total Housing Units

   Rapid transit community 25%

   Commuter rail community 15%

   Adjacent community 10%

   Adjacent small town 5%

   1. 1. To be deemed in compliance with M.G.L. c. 40A, § 3A, each MBTA community must have a Multi-family zoning district with a Multi-family unit capacity equal to or greater than the minimum unit capacity as determined by EOHLC in accordance with the Table 760 CMR 72.12. The minimum Multi-family unit capacity for each MBTA community has been determined as follows:

      1. a. First, by multiplying the number of housing units in that community by 0.25, 0.15, 0.10, or .05 depending on the MBTA community category. For example, a Rapid transit community with 7,500 housing units is required to have a Multi-family zoning district with a Multi-family unit capacity of 7,500 x 0.25 = 1,875 Multi-family units. For purposes of 760 CMR 72.00, the number of total housing units in each MBTA community has been established by reference to the most recently published United States Decennial Census of Population and Housing.
      2. b. Second, when there is a minimum land area applicable to an MBTA community, by multiplying that minimum land area (up to 50 acres) by M.G.L. c. 40A, § 3A's minimum gross density requirement of 15 units per acre. The product of that multiplication creates a floor on Multi-family unit capacity. For example, an MBTA community with a minimum land area of 40 acres must have a district with a Multi-family unit capacity of at least 600 (40 x 15) units.
      3. c. The minimum unit capacity applicable to each MBTA community is the greater of the numbers resulting from steps a. and b. above, but subject to the following limitation: In no case does the minimum Multi-family unit capacity exceed 25% of the total housing units in that MBTA community. Example: The minimum multi-family unit capacity for an Adjacent community with 1,000 housing units and a minimum land area of 50 acres is determined as follows: (i) first, by multiplying 1,000 x .1 = 100 units; (ii) second, by multiplying 50 x 15 = 750 units; (iii) by taking the larger number, but adjusting that number down, if necessary, so that unit capacity is no more than 25% of 1,000 = 250 units. In this case, the adjustment in step (iii) results in a minimum unit capacity of 250 units.

3. (c) Unit Capacity in Mixed-use Development Districts.

   1. 1. In making determinations of whether an MBTA community has a Multi-family zoning district of "reasonable size" under 760 CMR 72.05, EOHLC shall also take into consideration the existence and impact of Mixed-use development zoning districts, subject to the requirements below.

   2. 2. EOHLC shall take these Mixed-use development districts into consideration as reducing the unit capacity needed for a Multi-family zoning district to be "reasonable" (in accordance with Table 760 CMR 72.12. ) where:

      1. a. the Mixed-use development zoning district is in an eligible location where existing village-style or downtown development is essential to preserve pedestrian access to amenities;
      2. b. there are no age restrictions or limits on unit size, number of bedrooms, bedroom size or number of occupants and the residential units permitted are suitable for families with children;
      3. c. Mixed-used development in the district is allowed As of right as that phrase has been interpreted by EOHLC (for example, in 760 CMR 72.04(1)(b) with respect to affordability requirements);
      4. d. the requirement for non-residential uses is limited to the ground floor of buildings, and in no case represents a requirement that more than 33% of the floor area of a building, Lot, or project must be for non-residential uses;
      5. e. the requirement for non-residential uses does not preclude a minimum of three residential dwelling units per Lot;
      6. f. the requirement for non-residential uses allows a broad mix of non-residential uses As-of-right in keeping with the nature of the area; and
      7. g. there are no minimum parking requirements associated with the non-residential uses allowed As of right.
   3. 3. An MBTA community asking to reduce the unit capacity requirement for its Multi-family zoning district(s) based on the unit capacity for one or more Mixed-use development districts shall submit to EOHLC, on a form to be provided by EOHLC, a request for a determination that the Mixed-use development district is in an eligible location meeting the requirements of 760 CMR 72.05(1)(c)2.a. This request must be submitted at least 90 days prior to the vote of the MBTA community's legislative body. An MBTA community also may submit a broader inquiry as to M.G.L. c. 40A, § 3A compliance in accordance with 760 CMR 72.09(5). EOHLC shall respond prior to the vote of the MBTA community's legislative body if the request is timely submitted.

   4. 4. In any community with both a Multi-family zoning district and a Mixed-use development district that meets these considerations, the unit capacity requirement for the Multi-family zoning district, as stated in Table 760 CMR 72.12, shall be reduced by the lesser of:

      1. a. the unit capacity of Residential dwelling units in the Mixed-use development district or subdistrict (as calculated by EOHLC using a methodology similar to that in 760 CMR 72.05(1)(d) which takes into account the impact of non-residential uses), or
      2. b. 25% of the unit capacity requirement as stated in Table 760 CMR 72.12. This consideration shall not affect the minimum land area acreage or contiguity requirements for a Multi-family zoning district otherwise required by 760 CMR 72.00.

4. (d) Methodology for Determining a Multi-family Zoning District's Multi-family Unit Capacity.

   1. 1. MBTA communities seeking a determination of compliance must use the EOHLC Compliance model to provide an estimate of the number of Multi-family housing units that can be developed As of right within the Multi-family zoning district. The Multi-family unit capacity of an existing or proposed district shall be calculated using the unit capacity worksheet described in the Compliance Methodology Model. This worksheet produces an estimate of a district's Multi-family unit capacity using inputs such as the amount of Developable land in the district, the dimensional requirements applicable to Lots and buildings (including, for example, height limitations, lot coverage limitations, and maximum floor area ratio), and the parking space requirements applicable to Multi-family uses.
   2. 2. Minimum unit capacity is a measure of whether a Multi-family zoning district is of a reasonable size, not a requirement to produce housing units. Nothing in M.G.L. c. 40A, § 3A or 760 CMR 72.00 should be interpreted as a mandate to construct a specified number of housing units, nor as a housing production target. Demonstrating compliance with the minimum multi-family unit capacity requires only that an MBTA community show that the zoning allows multi-family housing as of right and that a sufficient number of multi-family housing units could be added to or replace existing uses and structures over time-even though such additions or replacements may be unlikely to occur soon.
   3. 3. If an MBTA community has two or more zoning districts in which Multi-family housing is allowed As of right, then two or more districts may be considered cumulatively to meet the minimum land area and minimum Multi-family unit capacity requirements, as long as each district independently complies with M.G.L. c. 40A, § 3A's other requirements and 760 CMR 72.00.

5. (e) Water and Wastewater Infrastructure within the Multi-family Zoning District.

   1. 1. MBTA communities are encouraged to consider the availability of water and wastewater infrastructure when selecting the location of a new Multi-family zoning district. Compliance with M.G.L. c. 40A, § 3A does not require a municipality to install new water or wastewater infrastructure, or add to the capacity of existing infrastructure, to accommodate future Multi-family housing production within the Multi-family zoning district. In most cases, Multi-family housing can be created using private septic and wastewater treatment systems that meet state environmental standards. Where public systems currently exist, but capacity is limited, private developers may be able to support the cost of necessary water and sewer extensions. While the zoning must allow for gross average density of at least 15 units per acre, there may be other legal or practical limitations, including lack of infrastructure or infrastructure capacity, that result in actual housing production at lower density than the zoning allows.
   2. 2. The Multi-family unit capacity analysis does not need to take into consideration limitations on development resulting from existing water or wastewater infrastructure within the Multi-family zoning district, or, in areas not served by public sewer, any applicable limitations under 310 CMR 15.000: The State Environmental Code, Title 5: Standard Requirements for the Siting, Construction, Inspection, Upgrade and Expansion of On-site Sewage Treatment and Disposal Systems and for the TransPort and Disposal of Septage. For purposes of the unit capacity analysis, it is assumed that housing developers will design projects that work within existing water and wastewater constraints, and that developers, the municipality, or the Commonwealth will provide funding for infrastructure upgrades as needed for individual projects.