Lot Coverage Limits: Ayer vs Cambridge
How do lot coverage limits rules compare between Ayer, MA and Cambridge, MA?
Ayer has fewer restrictions than Cambridge.
Ayer, MA
Middlesex County
Maximum lot coverage is set by municipal zoning under MGL c.40A. Residential districts commonly cap coverage at 25-40 percent; urban lots allow more.
View full Ayer rules →Cambridge, MA
Middlesex County
Cambridge regulates lot coverage and Floor Area Ratio (FAR) by zoning district, with Residence A limited to modest coverage and business districts allowing much higher intensity with inclusionary housing.
View full Cambridge rules →Key Facts Comparison
| Fact | Ayer | Cambridge |
|---|---|---|
| Suburban typical | 25-40 percent | - |
| Urban metric | FAR often used | - |
| Impervious cap | Tied to MS4 stormwater | - |
| Includes | Buildings, pools, decks | - |
| Relief | ZBA variance | - |
| Res A FAR | - | 0.5 to 0.75 |
| Res A coverage | - | About 35 percent |
| Business FAR | - | Up to 4.0 plus |
| Bonuses | - | Inclusionary, LEED |
| Open space | - | Required complement |
Highlighted rows indicate differences between cities.
Ayer FAQ
Does the driveway count?
Some bylaws include paved driveways in impervious surface limits even if not in building coverage.
What if I exceed the cap?
You must seek a variance or reduce the footprint before the building department will issue a permit.
Cambridge FAQ
What is FAR?
Floor Area Ratio is the ratio of total building floor area to lot area; a 0.75 FAR on a 5,000 sf lot allows 3,750 sf of floor area.
Can I get a coverage bonus?
Some bonuses exist for inclusionary housing and green building certifications via special permit.
Compare other topics
See how Ayer and Cambridge compare on other ordinance categories.
Want to add a third city?
Use our full comparison tool to compare up to three cities.
Open Comparison Tool