Scenarios — not predictions — for what Colchester's October 1, 2026 revaluation could do to home tax bills
Norwich's October 2023 revaluation raised 98.9% of home tax bills, the median by +27% (+$1,064/yr) — because homes were 51% of its tax base, and when homes rose +62% while commercial (+11%), cars and business equipment did not keep pace, a tenth of the whole levy shifted onto homeowners.
New here? How a Revaluation Moves Your Bill walks the mechanism lever by lever, and East Hampton’s page shows the same reset landing next door right now, measured.
Colchester's base is built differently: homes are already 70.9% of the grand list, and commercial, industrial and utility real estate is 8.5%. There is far less base to shift from, so the same market pattern produces a real but much smaller shift. Colchester's own 2021 revaluation also behaved differently — commercial rose +15.8% against residential's +22.5% (a 0.70 ratio, versus Norwich's 0.18) — and the business side of Colchester's list has been growing between revaluations: business personal property nearly doubled from $57.5M (GL 2020) to $113.4M (GL 2024), even as commercial real estate stayed flat within the cycle. The scenarios below carry all three patterns.
How is Colchester’s tax base built, against Norwich’s?
Colchester’s homes already carry 71% of the tax base; Norwich had roughly half of its base in non-home classes.
Each scenario grows Colchester's GL 2024 classes and resets the mill rate so the town collects the same dollars ("flat levy") or 6.1% more (the levy growth Norwich adopted in its revaluation year). Within homes, each of Colchester's 5,357 homes carries the home-to-home variation measured in Norwich, matched by value rank — cheaper homes rise more — rescaled to the scenario's residential total. Baseline FY 2025-26 rate: 29.92 mills on a median home assessed $198.4k (a $5,936/yr bill).
| Scenario | Mill rate | Median bill | $ / yr, median home | p10–p90 | Paying more | Car bill |
|---|---|---|---|---|---|---|
| With a flat levy (no budget growth) | ||||||
| Colchester's 2021 pattern (homes +45%) | 22.19 | +8.4% | +$465 | −2% to +24% | 86% | −31% |
| Norwich pattern, state path (homes +45%) | 22.56 | +10.2% | +$565 | −0% to +26% | 89% | −30% |
| Full Norwich magnitude (homes +62%) | 20.66 | +12.6% | +$710 | +2% to +28% | 93% | −36% |
| With Norwich-like +6.1% levy growth | ||||||
| Colchester's 2021 pattern (homes +45%) | 23.53 | +15.0% | +$845 | +4% to +31% | 96% | −27% |
| Norwich pattern, state path (homes +45%) | 23.92 | +16.8% | +$959 | +6% to +33% | 97% | −26% |
| Full Norwich magnitude (homes +62%) | 21.91 | +19.4% | +$1,110 | +8% to +36% | 98% | −32% |
Scenario definitions — Colchester's 2021 pattern: homes +45% (the FHFA Connecticut house-price path since Colchester's 2021 revaluation), commercial at 70% of the homes rate (+31.7%, Colchester's own 2021 ratio), apartments tracking homes. Norwich pattern, state path: homes +45%, commercial +11.2%, apartments at 55% of homes (Norwich's measured ratios). Full Norwich magnitude: homes +62%, Norwich's other class moves. All scenarios: motor vehicles −6.9% and personal property −6.0% (Norwich's path), exemptions held constant. Medians are soft by roughly half a point under alternative orderings of equal-valued homes. Unlike Norwich — whose car taxes were pinned at the statutory 32.46-mill cap — Colchester taxes vehicles at the real-estate rate, so the reval mill cut reaches car bills (the last column; rate effect × the citywide vehicle-value path).
Under each scenario, which homes would see an increase?
Where would the shift land across home values?
| Home type (flat levy, median) | Colchester's 2021 pattern | Norwich pattern, state path | Full Norwich magnitude |
|---|---|---|---|
| Mobile home (n=194) | +26.0% (+$375) | +28.0% (+$413) | +30.9% (+$458) |
| Condo / PUD (n=458) | +13.3% (+$562) | +15.1% (+$645) | +17.7% (+$744) |
| Two-family (n=147) | +9.0% (+$504) | +10.8% (+$589) | +13.3% (+$731) |
| Single-family (n=4,558) | +7.7% (+$460) | +9.4% (+$568) | +11.9% (+$722) |
Set the market and budget levers and see what they would mean for one Colchester home. Your current assessment is on your tax bill, or look it up by address on the tax calculator page. Estimates cover the real-estate levy plus a car-tax line, before exemptions and credits.
70% of appraised market value. Median Colchester home: $198,400.
Original MSRP, before depreciation. Set 0 to skip. Uses Colchester's local-option schedule, held unchanged through GL 2026.
The vehicle calculation covers ages below 20 at GL 2026 and the $500 assessment floor. Special assessments and exemptions are excluded.
The state house-price index is +45% since Colchester's 2021 revaluation; Norwich homes reset +62% over their five-year gap.
Norwich's 2023 revaluation: +11%. Colchester's 2021 revaluation: +15.8% (70% of its homes rate, which at +45% would be +32%).
0% = the town collects the same total dollars. Norwich adopted +6.1% in its reval year.
On: your home's rise is adjusted by where its value sits among Colchester homes, using Norwich's measured curve. Off: your home rises exactly with the homes average.
Model: presets use the full class assumptions in the scenario table. After a manual market change, apartments track homes, industrial tracks commercial and vacant land grows at 27% of the homes rate. Motor vehicle totals change −6.9% and business personal property −6.0%, following Norwich's path; exemptions stay constant. The levy-neutral mill rate is 29.92 × old base ÷ new base, and your bill change is your assessment's rise times the mill-rate ratio. The car line applies the local-option MSRP depreciation schedule separately to GL 2024 and GL 2026, with the $500 floor and vehicle rate cap. It does not apply the citywide value path to your vehicle. OPM vehicle schedule. The historical spread uses the 10th–90th percentiles within each Norwich value-rank bucket, divided by that bucket's median. It describes Norwich's variation, not a calibrated probability for a Colchester home. This is arithmetic on stated assumptions — not a forecast, and not a bill.
A fair question — the business side of Colchester's grand list has been growing. Here is what the data shows, and how much it can move the answer.
| Colchester class (CT OPM) | GL 2020 | GL 2021 (reval) | GL 2024 | Within-cycle change (2021→2024) |
|---|---|---|---|---|
| Commercial real estate | $100,427,890 | $116,330,880 | $116,690,585 | +0.3% |
| Business personal property (net) | $57,495,712 | $66,714,207 | $113,362,776 | +69.9% |
| Residential | $901,763,050 | $1,105,024,670 | $1,138,523,430 | +3.0% |
Two different measures of the same revaluation, and they are not interchangeable. Everything above is built parcel by parcel: 5,357 individual Colchester homes, each carrying Norwich’s measured home-to-home distribution, which is what produces a distribution rather than a single number. The two charts below are the statewide standard measure — one class average per property class, from CT OPM’s own sales ratios, computed identically for all 169 Connecticut towns. The parcel model says more about the spread between Colchester homes; the standard measure says more about where Colchester sits among its neighbors. Neither is a forecast, and the two are never combined into one figure.
Read together, they agree on the middle of the range: the standard measure puts a Colchester home that moves exactly with the residential class at the low end of the flat-levy range the scenarios above open with.
Bill scenarios need the town's dated grand list, rates and adopted budget. Loading data...
Starting assumptions are illustrative: spending +3% each year, state revenue unchanged, no further reserve use and no additional housing appreciation. Change them to reflect your expectations.
Sources: OPM adopted budgets, mill rates, grand lists, sales ratios, revaluation schedules and statutory aid estimates. Budget changes are applied proportionally to the baseline rate-derived levy. Vehicle rates are solved separately. All amounts are nominal dollars.
How far have assessments drifted from what property sells for?
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Source: CT OPM Equalized Net Grand List by Town (8rr8-a322), fields residential_ratio and cip_ratio, packaged as /data/ct_revaluation.json by Data/fetch_ct_revaluation.py. cip_ratio covers commercial, industrial and public-utility property together. The statewide line is the median of every town’s own residential ratio in that grand list year; this town is excluded from it. Ratios are keyed to the October 1 grand list year on the axis, not to a fiscal year. A ratio is measured from the sales that happened, so in a small town, or a class with few sales, it rests on very few transactions and OPM publishes no count of them here. Ratios outside 10–200 are treated as too thin to stand for a whole class and are not plotted.
What would the drift already measured do to a bill, with the levy held flat?
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Source: CT OPM Equalized Net Grand List by Town (8rr8-a322) for the class assessed values (residential_net, apartments_net, cip_net, vacant_net, land_use_net, ten_mill_net, total_personal_property_mvpp) and the sales ratio each carries; CT OPM Revaluation Years by Town, 2023–2037 (2se9-jnuq) for the scheduled year — both packaged as /data/ct_revaluation.json by Data/fetch_ct_revaluation.py. Each real-property class is stepped by 70 ÷ its own sales ratio; motor vehicle and personal property are carried unchanged. The bill change is the class assessment factor times the property-rate factor. The new property rate preserves the levy with vehicle revenue calculated separately using matching-year OPM mill rates (emyx-j53e) and net vehicle assessments (webp-fgt3). Vehicle rates cannot exceed 32.46 mills or an already lower published vehicle ceiling; special-district rates are excluded. Peer and statewide bars are the median of each town’s own figure computed the same way; this town is excluded from every median it is compared against. The schedule is the schedule as published, and revaluations do move — the legislature deferred several in 2020.
What is a homestead exemption, and what would it be worth here?
About 92% of claiming homes would pay less and about 8% — the most valuable ones — would pay slightly more.
An exemption takes assessed value off the taxable grand list. It does not by itself change the budget the town adopts, so raising the same dollars from a smaller list means a higher mill rate. Homeowners who claim the exemption pay less; bills that are not exempt pay more. Every figure below holds the levy fixed — the town collects the same dollars in each comparison — which isolates the exemption's own effect from whatever budget the town later adopts.
On Colchester's current list, 5,016 parcels are single-family homes or condominiums — the property types the exemption reaches. If every one of them claimed the full $50,000 — a ceiling rather than an expected outcome: the ACS counts 4,887 owner-occupied units in town across all housing types, so the number of eligible primary residences is smaller, and the take-up table below shows lower filing rates — the town would take $250.7 million, or 15.6%, off a net grand list of $1.606 billion. Holding the levy fixed, the mill rate would rise from 29.92 to 35.46, and every bill that is not a claiming home — commercial property, business equipment, apartments, motor vehicles, and any home that does not file — would rise 18.5%.
Median change in the annual real-estate bill for a claiming home, by tenth of GL 2024 assessed value, if every eligible home claims. The dashed line is what every other bill in town does at the same time. Because the exemption is a flat dollar amount, it is worth more as a share of a less valuable home: the bottom tenth (median assessment $121,400) would pay about 30% less, while the top tenth (median $346,650) would pay slightly more, the higher mill rate outweighing the fixed $50,000.
What would the exemption do on top of a revaluation?
Under Colchester’s own 2021 pattern with a flat levy, the exemption offsets much of the revaluation increase: a median claiming home is +8.0% against today’s bill after the revaluation alone and +1.2% with the exemption, a saving of about $393/yr.
| Scenario | Mill rate, reval only | Mill rate, with exemption | Median claiming home vs. today — reval only | — with exemption | Every other bill | Car bill vs. today |
|---|
Median over the 5,016 single-family and condominium parcels, so the two "vs. today" columns cover one population. "Every other bill" is the mill-rate rise the exemption adds on top of the revaluation's own rate change, and it applies to commercial property, business equipment, apartments, motor vehicles and any home that does not claim. The car column shows a second-order effect: the revaluation on its own cuts car bills by roughly a quarter to a third, because Colchester taxes vehicles at the real-estate rate and that rate falls; adopting the exemption raises the rate again and returns part of that cut.
The exemption requires an annual application, so the number of claims — not the number of eligible homes — sets the size of the shift. Shown on today's grand list, with a fixed levy.
| Homes claiming | Value off the list | Mill rate | Every other bill | Median claiming home | Claiming homes paying less |
|---|
For scale: the ACS counted 4,887 owner-occupied housing units in Colchester in 2024 (of 6,388 households, table B25003), across all structure types — so the number of primary residences is close to, but below, the 5,016 type-eligible parcels, before any allowance for owners who do not file. Note the direction of the trade-off: when fewer homes claim, the grand list shrinks less, the mill rate rises less, and the homes that do claim keep more of the benefit — the median claiming home is 10.8% better off at full take-up and 14.0% better off at 80%.
NorwichReval/ in the repository).Colchester2026WhatIf/ in the repository.Colchester2026WhatIf/homestead_model.py → homestead.json and homestead_page.json.