Proposal Details

This document has been updated to include the changes made in the resubmission of the AHO for the 2020/02/24 City Council meeting.

Most folks likely never need to think about the specifics of zoning: Unless you're trying to add an addition to your house, or make your living as a property developer, it's likely that you can get away for much of your life with never dealing with the details of a zoning ordinance. If the idea of thinking about specifics of zoning is not your cup of tea, then you really don't need to, and this is not the page for you.

You will likely get a better sense of what the changes under the overlay would be likely to be by taking a look at the sample site models that CDD prepared with an architect.

However, if getting involved in highly technical details of specifics of a change to how some buildings in Cambridge could be built appeals to you, here's the details on the proposed zoning change.

committee which may change some sections of this ordinance.

All comments in italics below are intended to help clarify the ordinance, and are intended to be the opinions of the author.

Section 1: Purpose and Intent

The introduction establishes the intent of the zoning section: to allow increases in density, limited increases in height, and relaxation of certain other zoning limitations for residential developments in which all units are made permanently affordable to households earning up to 100% of area median income. The intent of this zoning is that results of the design review process described in Section 8 of this language should inform the Cambridge Affordable Housing Trust's funding decisions, and that the design guidelines of the ordinance must be followed.

Section 2: Applicability

Establishes that the rules in the Affordable Housing Overlay apply citywide (except for open space districts, which are used for the City's current park space), and that properties must meet all requirements of the overlay, or they are not able to take advantage of this section of zoning. (This rules out using special permits or variances to get allowances around this set of zoning requiements: you either meet all requirements, or you meet none of them, and you proceed as you would with any other project.)

Section 3: Standards for Eligibility

The Affordable Housing Overlay has a somewhat complex set of guidelines around who is eligible for these developments, and what prices the units must be rented or sold at.

All Units

  • Must be rented or sold only to eligible households, with a preference for Cambridge residents or residents who have been forced to leave Cambridge in the last 12 months, where allowed by funding constraints.
  • Must have a permanent deed restriction attached to the property to ensure that all future sales have the same condition.

Rental Units

  • All units must be only made available to households making less than 100% of AMI; 80% must be for households making less than 80% of AMI. (This means up to 20% of units in a given development can be 'middle income' units.)
  • Rent, utilities and fees can not exceed 30% of gross income, but can be lower. (For example: a household with a gross income of $60k/year would have a maximum monthly housing cost of $1500/month.)
  • Income is verified annually, and can not exceed 120% of AMI for more than one year for households in AHO units.

Ownership Units

  • All units must be only made available to households making less than 100% of AMI; 50% must be for households making less than 80% of AMI. (This means up to 50% of units in a given development can be 'middle income' units.)
  • Sale price will be approved by the Community Development Department, which will ensure that mortgage and holding costs (utilities, mortgage insurance, monthly payments, etc.) are no more 21% or 27% of the median income for 80% AMI and 100% AMI units respectively.

Section 4: Use

The overlay provides for all types of housing in every district: single-family, two-family, townhouse, or multifamily dwellings are allowed. (This is a change primarily for the existing single family and two family zones that make up most of West Cambridge and northern Cambridge, the "A-1", "A-2", and "B" zones, which do not currently allow apartments.)

The overlay allows for retail or commercial services open to the public on the ground floor, where those uses are allowed in the base zoning district. (This means the buildings don't have to be 100% housing: in existing commercial districts, they can have ground floor retail, or other allowed uses in the district.)

Section 5: Development Standards

This is where the most significant changes under the overlay are established.

General Provisions

Developments under the overlay are "by-right", meaning they do not require a special permit or variance. Since there is no discretionary approval by the Planning Board or Board of Zoning Appeals, these decisions can not be appealed by abutters.

For developments that meet the requirements of the overlay, the overlay dimensional standards are the only ones that apply. If the base district is less restrictive, the base district standards apply.

Dimensional Standards: Height and Stories

In zones that allow heights of 40' or less today, AHO developments must be no more than 4 stories tall. They must also be less than 45' tall, unless they contain a non-residential first floor, in which case they must be less than 50' tall.

In zones that allow heights between 40' and 50' today, AHO developments must be no more than 6 stories tall. They must also be less than 65' tall. Where a building is within 35' of housing in a lower-height district, that portion of the building has a height which must match the lower-height district conditions above.

In zones that allow heights higher than 50' today, AHO developments must be no more than 7 stories tall. They must also be less than 80' tall. Where a building is within 35' of housing in a lower-height district, the maximum height is reduced to 60', and the maximum number of stories is 5.

No dwelling units are allowed below grade.

Where the existing district establishes a maximum floor area ratio (FAR) of less than 1.00, an AHO development shall not exceed an FAR of 2.00. Otherwise, there is no maximum FAR for an AHO development; there is no lot size per unit minimum for AHO developments.

Dimensional Standards: Setbacks

Front yard setbacks are 15 feet, or the average of four nearby two-story tall buildings, whichever is less. Side yard setbacks are 7.5 feet. Rear setbacks are 20 feet. Corner lots may have setbacks reduced to 10'. For all setbacks, if the the district has a lower standard, it follows the district standard.

Bay windows, small balconies, and uncovered porches can be in setbacks. Bicycle parking can be in setbacks, but not within 7.5' of an abutting building.

Dimensional Standards: Open Space

Developments are required to have 30% open space; this can be lowered to as low as 15% if the development includes preservation of a building on the state register of historical places.

The space is considered "private open space". It does not include parking or driveways for cars (subject to the constraint above).

All of the required open space at grade level must be permeable open space (ie, not asphalt/pavement). Open space must be at or below the level of the first floor except shared roof decks / balconies, which can offer up to 25% of the total open space.

Bicycle parking space is open space.

Dimensional Standards: Existing Buildings

Modifying the inside of existing buildings is allowed, even if they exceed the limits of the ordinance.

You can add insulation to the exterior of an existing building, extending up to an additional 8" into the setbacks.

You can move the building on the lot, so long as you don't make the setbacks or height more out of conformance than they currently are.

So long as you maintain the current amount of open space, you can make changes; building bike parking or accessibility improvements doesn't count as a reduction of open space.

Section 6: Parking and Bicycle Parking

Off-street parking is not required except to comply with requirements of the ADA and necessary loading, unloading, and short-term parking zones. (This eliminates parking requirements, allowing developers to cater parking to the building being built.)

Parking can be provided in an existing parking facility within 1000', so long as the development can provide evidence of a long-term lease. Parking can be provided in tandem parking spots (two cars in a space). Parking can be within 10' (but not closer than 7.5') of a building. Parking can be near lot lines, so long as there is screening or planting blocking the parking from neighbors.

Bicycle parking can be included anywhere on the lot (rather than needing to be within 200' of an entrance). Up to 20 additional long-term spaces can fulfill the requirements for short-term spaces. Required bicycle parking will be reduced by half (up to 28 spaces) if the developer of the AHO property installs a bike sharing dock on the property or within 500'. Units in an existing building do not require bicycle parking.

If a property's parking requirement is waived, the owner must offer a free annual bike share membership or three months of 50% discounted MBTA passes for two individuals on initial occupancy, and provide information on nearby transit routes on occupancy or a real-time transit route display on the property.

Section 7: Building and Site Design Standards for New Development

The AHO Design Standards are the only requirement for AHO projects, but they are encouraged to follow existing design standards. Existing buildings are not required to follow the design standards.

Site Design and Arrangement

The area between the front lot line and the front of the house must contain only landscaped areas, patios or uncovered porches, or areas for pedestrians and bicyclists. Motor vehicle use is limited to 30' of driveway per 100' of frontage.

Pedestrian entrances must be visible from the street; access to pedestrian entrances must be accessible by routes separate from car access.

A building footprint more than 150' in length must have portions set back at least 15' in depth and 15' in width from the front lot line. (This is designed to prevent very long frontages, but realistically will be very rare, since very few properties have 150' of frontage along a road.)

Building Facades

At least 20% of building facades along a public street must be glass. In Business Districts, this is increased to 30% for non-residential portions.

Every 40' along a street, and every 80' elsewhere on the facade, facades must incorporate architectural elements that project or recess by at least two feet from the adjacent section. This requirement does not apply to the first floor or to the top two floors or 6 or 7 story buildings. This is intended to cause incorporation of elements that promote visual interest and residential character. (This is designed to minimize large blocky frontages, requiring bay windows and similar treatments to break up facades.)

Developers are encouraged to include elements that promote visual interest around windows that face streets and public open spaces.

Ground Floors

The ground floor of the buildings must be no higher than 4' above ground level; in cases of active ground floor use, this must be at ground level. This requirement does not apply if a change is necessary for flood protection.

If the ground floor of the building includes parking, at least 50% of the street-facing area must be housing units or other populated areas of the building to screen the parking from the street.

The ground floor of buildings must have transparent windows or pedestrian entrances at least every 25'.

For active first floor uses, the height of the first floor space must be at least 15', the depth of the space must be 35', and it the facade shall be at least 50% transparent windows.

Buildings in business districts may include commercial or social service spaces on the ground floor. (This allows projects to include retail or social service spaces like daycares where they are appropriate, but does not require them.)

Mechanical Equipment, Refuse Storage, Loading Areas

Mechanicals, refuse storage, and loading areas must meet the following standards:

  • Can not be in any setback (unless required by a utility company)
  • Must be screened from the street and adjacent properties at the property line
  • If on the roof, screened from the ground level of the streets, and any adjacent residential lots
  • Must meet city noise regulations.
  • Trash facilities must be contained in the building or screened until disposed of.

Environmental Design Standards

AHO Projects are subject to green building requirements, flood plain requirements, and state and local laws regarding environmental standards.

All newly installed outdoor lights must be shielded to not egress light onto adjacent residential lots.

Section 8: Design Consultation Process

  1. Prior to getting a building permit, AHO projects must have a community meeting, and inform all abutters of the meeting.
  2. The developer of an AHO project must prepare a detailed plan of the project to be presented to the Planning Board. This includes drawings, landscape plans, elevations, site photos, material palettes, and so on, as well as a brief narrative of the plans for the project.
  3. The Planning Board will schedule a public meeting for a design consultation. At the meeting, they can ask the developer and City staff questions, and take public comment.
  4. The Planning Board will evaluate the project for City guidelines -- both AHO specific and general -- as well as make suggestions regarding other development in the area, and suggest specific project changes to better comply with the ordinance. This report will be communicated within 20 days.
  5. The developer then works with CDD staff to respond to the recommendations of the Planning Board, and submits revised documents.
  6. Once the documents are received, the Planning Board schedules a second design consultation meeting, where they can offer any additional suggestions regarding specific project changes.
  7. This report goes on to the Superintendent of Buildings, who will use it to confirm the development meets the requirements of the Affordable Housing Overlay.

Section 9: Implementation

The City Manager will create rules for implementation of this plan.

The Community Development Department will develop standards and procedures for their work under this ordinance.

Section 10: Enforcement

The Community Development Department has to confirm in writing that all the requirements of this zoning ordinance have been met before a building permit is granted, and before any permit for occupancy is granted.