Two Simsbury property owners tried to add a secondary living space to their homes within about two years of each other. Both filed with the town. Only one got a yes.
At 8 Ann-March Lane, John and Kirsten Carew worked with Pennwood Builders on a 600-square-foot attached accessory dwelling unit in an R-40 zone. The Zoning Commission approved it as submitted. Across town at 444 Bushy Hill Road, owner Niles Kelly got the green light for a 624-square-foot detached unit the same year. Then in November 2025, an application at 6 Banks Road asked for something more: two setback variances and permission to build a unit topping out at 1,021 square feet, about 421 square feet over the standard cap. The Zoning Board of Appeals said no.
If you're comparing Simsbury to other Farmington Valley towns and you've read that Connecticut legalized accessory dwelling units statewide in 2021, you might assume the question is settled everywhere. It isn't. Simsbury's own permit records show a town that was never simply defaulting to the state's streamlined standard, and in 2025 the town rewrote its local rules again. What changed, and where in town you're standing when you ask, matters far more than the headline law most buyers cite.
The Law Everyone Quotes Isn't the One In Force
Public Act 21-29 set a statewide baseline in 2021: at least one accessory dwelling unit per single-family lot, attached or detached, capped at 1,000 square feet or 30 percent of the primary home's floor area, whichever is smaller, with no more than one required parking space and no restriction on who could live there. The state also built the standard around administrative, staff-level review, no special public hearing required. Towns had until January 1, 2023 to opt out of that baseline through a two-thirds vote of both their zoning commission and their legislative body, and reporting from CT Mirror on the Desegregate Connecticut implementation study found that roughly 115 towns statewide took that route.
Whatever Simsbury's exact opt-out paperwork says, its actual permit files tell a clear story. The approved applications at Ann-March Lane and Bushy Hill Road didn't move through simple staff review. One required full Zoning Commission Site Plan approval, the other a Special Exception hearing, both more involved than the streamlined process the state standard was built to guarantee. That gap between what the state law promised and what the town was actually enforcing is exactly why Simsbury's zoning commission went back to the table in 2025.
What Simsbury Did With Local Control
That table visit produced a package of three changes, approved in early 2025 and reported by the Stamford Advocate. The commission removed procedural barriers that had made attached and detached ADUs harder to permit. It created an entirely new small-lot zoning district, R-8, with an 8,000-square-foot minimum lot size that also permits two-family homes, something the town's older single-family zones don't allow. And it revised the town's most flexible housing tool, the housing strategies floating zone.
Town Planner George McGregor framed the changes as a way to build "a broad range of housing opportunities for people of all ages, at all price points." Not every resident agreed. Joan Coe, a Simsbury homeowner, described the package at the time as social engineering that infringed on property rights. Local builder Chris Nelson, whose past projects in town include Mill Commons and Mill Pond Crossing, testified in support, calling for the ADU process to be simplified further.
The point for a buyer isn't which side of that debate is right. It's that the rules changed in 2025, well after most ADU explainer content on the internet was written, and they changed in a specific, geographically uneven way.
Why Lot Size Doesn't Predict the Answer
Here's the assumption worth checking before you fall in love with a listing: bigger lot, easier secondary unit. The Banks Road case argues against it. That property sits in an R-40OS zone, meaning it likely carries close to an acre or more, yet the size and setback math still tripped up the application. The commission's standard caps and yard requirements apply regardless of how much land surrounds the house.
Meanwhile, the town's newest tool, the R-8 zone, was built for the opposite end of the lot-size spectrum. An 8,000-square-foot minimum is a fraction of what you'll find on Talcott Mountain-facing parcels in West Simsbury, where SmartMLS data for the first quarter of 2026 put the median sale price near $545,000 on the strength of 2 to 5 acre lots and mountain views, well above the roughly $340,000 median in Tariffville over that same period. R-8 is aimed at smaller, often older parcels closer to the village grid, not the estate-scale properties that read as most ADU-friendly on paper.
So the mechanism runs backward from intuition. The large-lot zones still enforce hard caps that can sink an oversized proposal, as Banks Road shows. The small-lot zone is the one the town just built specifically to unlock secondary units and two-family use. If you're touring homes with income potential or multigenerational living in mind, the acreage on the listing sheet tells you less than the zoning letter on the town's map.
| Track | What it allows | Where it tends to apply |
|---|---|---|
| Pre-2025 ADU process (now with fewer procedural barriers) | One attached or detached unit, standard size cap, subject to setbacks | Existing single-family zones like R-40, town-wide |
| New R-8 small-lot zone (2025) | Two-family homes by right on lots as small as 8,000 sq ft | Smaller, often in-town parcels, not the larger West Simsbury estate lots |
| Housing strategies floating zone (revised 2025) | More flexible design standards, case-by-case | Applied selectively, not a blanket rule |
The Market Context That Makes This Worth Checking Now
Simsbury isn't a market where a buyer has months to research zoning after the fact. As of June 30, 2026, Zillow's home value index for Simsbury showed homes going to pending in about four days town-wide. That's not universal: in Simsbury Center specifically, Redfin data through December 2025 showed homes taking an average of 41 days to sell, up from 27 the year before, with the median sale price down 12.8 percent year over year to $430,000. The village center and the outer town are not moving at the same speed or in the same direction.
That unevenness is exactly why the zoning question matters before you write an offer, not after. A property that can legally add rental income or an in-law suite is a different financial proposition than one that can't, and in a market where well-priced homes in some pockets still move in days, you don't get a second look to figure that out.
What This Means If You're Comparing Simsbury to Another Town
Don't ask "does Connecticut allow ADUs." Ask which of Simsbury's three local tracks applies to the specific parcel you're considering, and get the zoning district letter, R-40, R-40OS, or R-8, before you assume anything about what the lot can support. The state law is the floor other towns default to. Simsbury wrote its own answer, and that answer depends on where you're standing.
A Few Questions Worth Asking Directly
Can I rent out a Simsbury ADU short-term, like on a nightly basis? Yes, under the town's rental property ordinance, but it requires a permit, a certificate of zoning compliance, and is capped at 100 days per year under a two-year renewable permit.
Is the new R-8 zone available on any lot I like? No. It's a specific district the town created in 2025, not an overlay applied everywhere. You need to confirm the parcel actually sits within it before counting on two-family use.
What happens if my planned addition exceeds the size cap? You'd need a variance from the Zoning Board of Appeals, and outcomes vary. The standard-size applications at Ann-March Lane and Bushy Hill Road were approved. The oversized request at Banks Road was denied.
Zoning history like this doesn't show up on a listing sheet, and it changes faster than most online guides get updated. If you're weighing Simsbury against another Farmington Valley town and want to know what a specific property can actually support, Meghan Girard can walk the parcel-level detail with you before you write an offer, not after.
