Cambridge, MA Building Setbacks & Zoning: Setback Rules (2026)
Key Facts
- Res. C-1 min. front yard
- 10 feet
- Res. C-1 min. side/rear yard
- 5 feet
- Shared-wall buildings
- 0 ft. setback allowed
- Opposite side-yard offset rule
- sum of 10 ft. minimum
- Pre-2010 insulation encroachment
- up to 8 inches
- Governing table
- Zoning Ordinance Table 5-1, § 5.30
Summary
Residence C-1 lots in Cambridge must keep a 10-foot front yard and a 5-foot side or rear yard under the Zoning Ordinance's dimensional table. A dwelling need not set back further than the average of its immediate neighbors' setbacks, and shared-wall buildings can drop the side or rear setback to zero.
(3) A dwelling need not be set back from the street line, or building line where such may have been established on the lot, more than the average of the setbacks of the buildings, other than accessory buildings, on the lots adjacent thereto on either side. (4) The required side or rear yard setback may be reduced in either of the ways described below: (a) No side or rear yard setback shall be required for a building or portion thereof that directly abuts a building or portion thereof on an adjacent lot, as in the case of semi-detached dwellings or other adjoining buildings that share a party wall.
Full Breakdown
30, Table 5-1 of the Cambridge Zoning Ordinance sets the Residence C-1 district's minimum front yard setback at 10 feet and its minimum side or rear yard setback at 5 feet for residential and religious-purpose uses. Footnote (3) softens the front-yard number: a dwelling need not be set back from the street line, or an established building line, more than the average of the setbacks of the non-accessory buildings on the adjacent lots on either side. Footnote (4) allows the side or rear setback to shrink two ways: no side or rear setback is required where a building directly abuts a building on the adjacent lot sharing a party wall (as with semi-detached dwellings), and the setback on one side of a lot may be reduced if the two opposite side setbacks together total at least 10 feet and no part of the building comes within 10 feet of an existing building on the abutting lot.
For alterations or additions to a building that existed on or before January 1, 2025, the required side and rear setbacks are those of the existing building, though any horizontal extension beyond the existing walls must meet the Table 5-1 standards as modified by those same reductions. 5 feet on buildings up to 35 feet tall. 3 applies front-yard rules from every abutting street on corner lots, with remaining sides governed by the side-yard standard.
Violations & Fines
Inspectional Services checks proposed setbacks against Table 5-1 and its footnotes before issuing a building permit; encroachment into a required 10-foot front or 5-foot side/rear yard without qualifying under Footnote (3) or (4) requires a variance from the Board of Zoning Appeal under Section 10.30. Section 5.24.2 separately allows existing pre-2010 buildings to encroach up to 8 inches into a required yard solely to add exterior insulation, or more with a BZA special permit meeting the Section 10.43 criteria.
Frequently Asked Questions
What is the minimum front yard setback in Cambridge's Residence C-1 district?
Can a Cambridge rowhouse have a zero side setback?
Do fences and bike racks have to meet the yard setback?
Sources & Official References
Other rules in Cambridge
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Setback Rules in Nearby Cities
How other cities in this county handle setback rules.