Zoning & Size Limits
| Requirement | Cambridge, MA | Worcester, MA |
|---|
| Allowed Zones | All residential districts - Cambridge eliminated single-fami | All zoning districts - by-right on any lot with a lawfully e |
| Max Size (Detached) | 900 sq ft or 50% of primary dwelling, whichever is less (MA state by-right cap) | 900 sq ft by-right (larger is possible via Planning Board special permit) |
| Max Size (Attached) | 900 sq ft or 50% of primary dwelling, whichever is less (MA state by-right cap) | 900 sq ft by-right (larger via special permit) |
| Max Height | No ADU-specific cap - an ADU may match the princip | No ADU-specific cap - the most permissive of the d |
| Parking Required | None - Cambridge abolished all parking minimums citywide in | No additional parking required for an ADU (existing required |
| Owner Occupancy | Not required (prohibited under MA Affordable Homes Act / 760 | Not required (owner need not live on the property; prohibite |
Setback Requirements
| Setback | Cambridge, MA | Worcester, MA |
|---|
| Rear Setback | 5 ft base (ADU setbacks may not be stricter than principal/accessory standards under 760 CMR 71.03) | 5 ft via the accessory-structure standard (R districts) |
| Side Setback | 5 ft base | 5 feet |
| Front Setback | 10 ft base | ADUs may not be placed in the front yard |
Permits & Timeline
| Detail | Cambridge, MA | Worcester, MA |
|---|
| Permit Timeline | 60-90 days | 60-80 days |
| Permit Fees | $3,500-$5,500 | $2,800-$4,500 |
| Impact Fees | $1,500-$2,500 | $1,000-$1,800 |
| Pre-Approved Plans | Not available | Not available |
Construction Costs
| Cost | Cambridge, MA | Worcester, MA |
|---|
| Avg Build Cost | $210,000-$420,000 | $140,000-$280,000 |
| Cost Per Sq Ft | $220-$440 | $165-$330 |
| Garage Conversion | $105,000-$230,000 | $70,000-$160,000 |
| Prefab ADU | $160,000-$340,000 | $110,000-$250,000 |
Rental Income Potential
| Rental | Cambridge, MA | Worcester, MA |
|---|
| 1BR Avg Rent | $1,900-$2,500/mo | $1,250-$1,650/mo |
| 2BR Avg Rent | $2,300-$3,400/mo | $1,550-$2,150/mo |
| Short-Term Rentals | Not permitted | Not permitted |
| Est. ROI | 5-7% annual return | 7-10% annual return |
Which City Is Better for ADUs?
Cambridge scores 8/10 while Worcester scores 6/10 on our ADU-friendliness index.
Cambridge edges ahead overall. Both cities offer viable ADU development opportunities — the best choice depends on your specific property, budget, and goals.
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