Greenwich real estate, measured.
A stable view of Greenwich, Connecticut home prices, housing inventory, sales velocity, and market heat—built from public, source-linked records without letting one unusual month define the trend.
Greenwich Market Dashboard
The main view now runs from 2001 to the present. The solid green line is the quality-adjusted Address Index built from repeat sales of the same properties; the dashed gold ending is a transparent nowcast after complete transaction coverage. “Recent” keeps a full year of fitted history visible before the nowcast; use 5Y for a wider current-cycle view.
Synthetic Twin
Choose a completed sale to inspect its out-of-sample model expectation, a tighter likely zone, broader uncertainty, the public facts behind it, and where its earlier twins sit across Greenwich.
Synthetic Twin · 147 Old Church Road
147 Old Church Road sold for $2.80M, 33.0% below its $4.18M out-of-sample expectation. Its 50% likely zone is $3.62M–$4.83M; the 80% broader range is $2.89M–$6.05M. The model used 4,813 training, 1,054 calibration, and 1,055 untouched test sales; test median error was 16.5%. This is a market comparison, not an appraisal.
Get the judgment, not just the charts.
Explore the live Greenwich dashboard freely. Paid Address Index membership delivers the complete weekly analysis, adjusted comparable-sale work, model diagnostics, monthly State of Greenwich deep dives, and the paid archive—all through Substack, with no second login.
Price, leverage, liquidity, and the long view
The Same House Test · Greenwich
Among eligible repeat-sale intervals, 1,568 carry public evidence of rebuilding or substantial modernization and 3,824 have no recorded major change. Since the 2001 base, their modeled resale paths reached 402 and 221, respectively, versus 277 for all repeat sales. This is an evidence split, not a renovation-return estimate.
Greenwich Market Level · Monthly Reports
The Greenwich 12-month market level was $3.26M in July 2026, -2.3% from a year earlier. Monthly medians are shown as mix-sensitive context, not connected as a trend.
How Long Greenwich Homes Take to Sell
Greenwich single-family homes averaged 36 days on market in July 2026, versus 50 a year earlier. The trailing 12-month average was 60 days. A separate Realtor.com ZIP composite extends the directional history to July 2016; it measures median listing time, not GAR's average for sold homes. Its latest 12-month average was 50 days, versus 67 a year earlier.
Supply, Sales and Speed
Greenwich ended July 2026 with 113 active single-family homes, 74 closings, and an average 36 days on market.
Buyer–Seller Leverage
Greenwich's leverage score was 53/100 in July 2026 (balanced). The score ranks four public market signals against the displayed Greenwich history; it is a relative balance gauge, not a forecast.
Inventory Runway · Months of Supply
At the recent closing pace, Greenwich's 113 active single-family homes represented 2.6 months of supply in July 2026. This is a pace estimate, not a prediction that every listed home will sell.
The Luxury Mix · Where Greenwich Sales Are Clearing
In the trailing year through 2025 Q3, 32.7% of 505 deduplicated public sales cleared at $4M or more, including 7.1% at $8M+. This chart measures sales mix, not appreciation.
Model Surprise Map · Where Sales Beat or Missed Expectations
Across 48 untouched recent test sales, the median result was -3.2% versus the pre-sale public-record expectation; 48 have verified public coordinates. Select a point in the interactive dashboard to inspect the sale. This is model-error context, not an appraisal or a neighborhood ranking.
Market heat
Balanced
A relative score of price momentum, inventory tightness, market speed, and trailing sales liquidity.
Heat score components
Monthly tape
| Month | Reported median | 12-month signal | Market-level index | Closings | Inventory | Supply | Leverage | Days |
|---|---|---|---|---|---|---|---|---|
| Jul 2026 | $3.60M | $3.26M | 117.7 | 74 | 113 | 2.6 mo | 53 | 36 |
| Jun 2026 | $3.81M | $3.25M | 117.4 | 58 | 122 | 2.8 mo | 52 | 37 |
| May 2026 | $3.15M | $3.26M | 117.7 | 50 | 114 | 2.6 mo | 48 | 69 |
| Apr 2026 | $4.00M | $3.22M | 116.3 | 36 | 99 | 2.2 mo | 61 | 39 |
| Mar 2026 | $2.79M | $3.16M | 114.0 | 29 | 89 | 2.0 mo | 53 | 85 |
| Feb 2026 | $2.57M | $3.28M | 118.3 | 21 | 79 | 1.8 mo | 66 | 57 |
| Jan 2026 | $4.49M | $3.38M | 122.0 | 37 | 74 | 1.7 mo | 71 | 91 |
| Dec 2025 | $3.15M | $3.34M | 120.6 | 47 | 56 | 1.3 mo | 76 | 65 |
| Nov 2025 | $3.06M | $3.32M | 119.8 | 44 | 96 | 2.2 mo | 76 | 69 |
| Oct 2025 | $2.98M | $3.25M | 117.4 | 36 | 120 | 2.8 mo | 60 | 83 |
| Sep 2025 | $2.70M | $3.29M | 118.6 | 31 | 119 | 2.8 mo | 80 | 31 |
| Aug 2025 | $2.80M | $3.34M | 120.5 | 58 | 109 | 2.5 mo | 82 | 55 |
Latest Address Index quarters
| Quarter | Index | 95% interval | Evidence | Repeat-pair evidence |
|---|---|---|---|---|
| 2026 Q2 | 106.2 | 90.6–124.7 | nowcast | 0 |
| 2026 Q1 | 103.2 | 90.0–118.3 | nowcast | 0 |
| 2025 Q4 | 109.1 | 97.3–122.3 | nowcast | 0 |
| 2025 Q3 | 107.4 | 102.2–112.8 | observed | 94 |
| 2025 Q2 | 105.8 | 101.0–110.8 | observed | 84 |
| 2025 Q1 | 102.3 | 98.2–106.6 | observed | 65 |
| 2024 Q4 | 102.0 | 99.3–104.6 | observed | 72 |
| 2024 Q3 | 100.4 | 98.9–101.9 | observed | 117 |
| 2024 Q2 | 99.3 | 97.8–100.8 | observed | 99 |
| 2024 Q1 | 98.4 | 96.1–100.7 | observed | 61 |
| 2023 Q4 | 92.6 | 88.9–96.3 | observed | 67 |
| 2023 Q3 | 90.2 | 86.0–94.6 | observed | 115 |
Method and data quality
Address Index
A weighted repeat-sales model of the same Greenwich single-family properties over time. Quarterly estimates are smoothed over four quarters and scaled so the 2024 average equals 100.
Same House Test
Splits repeat-sale intervals into 1,568 with public evidence of rebuilding or substantial modernization and 3,824 with no recorded major change. It is an evidence comparison, not an estimate of renovation ROI.
Synthetic Twin
The data stays chronological: 4,813 earlier sales fit the model, 1,054 later sales set the ranges, and 1,055 newest sales remain untouched for the final test. Median test error is 16.5%. The 50% likely zone captured 51.3% of test sales; the 80% broader range captured 82.1%. Market comparison, not an appraisal.
Observed, reconstructed, nowcast
Observed quarters have direct state transaction coverage. Reconstructed quarters rely more heavily on public parcel sale histories or interpolation. After 2025 Q3, the dashed line is a transparent nowcast from official monthly reports.
Monthly dots
Each gold dot is the official median for one month. The dots are not connected because they describe different baskets of sold homes and should not be read as month-to-month appreciation.
Time on market
The long-run line is a listing-count-weighted composite of Realtor.com median listing time across Greenwich's five ZIP codes since 2016. The recent GAR line is the reported average for sold single-family homes. They are labeled separately because they are not the same statistic.
Buyer–Seller Leverage
Applies the published Market Heat weights to every complete month. Below 35 is buyer-leaning, 35–65 balanced, and above 65 seller-leaning. It is relative to the displayed Greenwich history, not a promise about a particular negotiation.
Inventory Runway
Active single-family inventory divided by the monthly closing pace implied by the trailing 12 months. It measures buyer choice at the recent pace—not how long a particular listing will take to sell.
The Luxury Mix
Groups 17,610 deduplicated public sales into four nominal price bands and shows each band’s trailing four-quarter share. The latest available transaction quarter is labeled separately because it can lag monthly reports. Mix is not appreciation.
Model Surprise Map
Plots verified coordinates for untouched Synthetic Twin test sales. Green cleared more than 10% above the chronological public-record expectation, gold more than 10% below, and gray within ±10%. It shows where the public model missed—not why.
Uncertainty
The shaded range is a 95% statistical interval. It widens when direct observations are sparse and widens further for the current nowcast. The center line is an estimate, not an appraisal.
Current coverage
20,159 state transaction rows, 4,842 Town archive rows, 19,364 parcel records, and 5,538 eligible repeat-sale pairs.
Sources and audit
State transactions · Town assessor archive · Town GIS map · listing-time history · latest market report · validation JSON.
Directional market intelligence only—not an appraisal, brokerage opinion, or investment recommendation.