Citizen Transparency Record · New Castle County, Delaware

The 2024 Reassessment: what the record actually shows

New Castle County's first property reassessment since 1983 revalued 214,788 parcels, shifted tens of millions of dollars of tax burden onto homeowners, triggered a special session of the General Assembly, two court rulings, five legislative hearings, and a still-running quality-control review. This page assembles the primary record — court opinions, the vendor's own appraisal report, ordinances, tax warrants, FOIA releases, hearing video, official statements and public reaction — and visualizes it five ways. Every number below links to its source.

Compiled 15 August 2026· 151 distinct linked sources · 333 citations· Sources: Delaware Courts · General Assembly · newcastlede.gov · Tyler Technologies · Spotlight Delaware · WHYY · WDEL · Delaware Public Media · Delaware Online
Court-ordered remedy (2020) Vendor: Tyler Technologies Effective value date: 1 July 2024 HB 242 split rates upheld SB 228 quality-control review Bills now due 31 Dec 2026

Scale of the event

Six numbers that define the rollout

Each figure is drawn from a primary document, not from summary reporting, except where a news outlet is the only public record of a hearing statement.

214,788
active parcels revalued, aggregate market value $120.06B as of 1 Jul 2024
41 yrs
since the previous countywide reassessment (1983) — the gap the Chancery Court found unconstitutional
+$39M
extra taxes on New Castle County homeowners in the first post-reassessment bills, per the State's counsel at trial
+316%
median increase in non-residential assessed value ($123K → $512K), the baseline for the SB 228 audit threshold
5,200+
formal appeals to the Board of Assessment Review, after ~11,500 informal hearings with Tyler
55%
of those 11,500 informal reviews turned up inconsistencies, per testimony recounted after the first legislative hearing
"This is why you can't wait 40-plus years to do a reassessment." — County Executive Marcus Henry, to Spotlight Delaware, 19 Feb 2026

Visualization 1 · Interactive record timeline

Every document in the chain, on one axis

Each dot is a primary artifact — a court opinion, statute, ordinance, mailed notice, FOIA release, hearing, press statement or piece of public reaction. Filter by type, hover for detail, click a dot to open the source. The record runs from the 2018 school-funding lawsuit to the tax bills due 31 December 2026.

Selected artifact

Click any dot

Selecting an item shows what it is, who produced it, why it matters, and a direct link to the underlying document or recording.

Dots are jittered vertically within their category band to avoid overlap; horizontal position is the true date. Where an artifact is only publicly documented through news coverage (for example, statements made during a hearing), the outlet is cited as the record.

Visualization 2 · Burden shift

How rates moved when HB 242 split them

In July 2025 every New Castle County school district billed one rate for all property. Three weeks later, under House Bill 242, six districts reset rates: down for homes, up for apartments, commercial, industrial and utility parcels. The revenue pie could not grow — only be re-sliced. Toggle the view, hover a line for the exact warrant figures.

Rates in dollars per $100 of assessed value, applied to post-reassessment (1 July 2024) values. Sources: County "Non-Residential" explainer (PDF), Revised 2025-26 rate schedule, 21 Nov 2025 (PDF), County Ordinance 25-048 (PDF), Spotlight Delaware rate table.
52.6% → 62.9%
residential share of Colonial School District's tax base before vs after reassessment — a 10.3-point shift the split rate was designed to undo
73.97 / 26.03
the residential / non-residential burden split Red Clay chose to "preserve" from before reassessment
1.85×
non-residential multiplier cap in the 2026 successor law, HB 462, down from 2× in HB 242
$1.00B
assessed value reclassified residential → non-residential (vs $116M the other way), per the County CFO's declaration at trial

Visualization 3 · Who got hit

The increase landed hardest on the poorest neighborhoods

Spotlight Delaware obtained parcel-level 2024 and 2025 assessment rolls from all three counties by FOIA and mapped median change by neighborhood with Tech Impact's Data Lab. In New Castle County the pattern inverted expectations: Wilmington's lowest-income blocks saw the largest percentage increases; château-country and the Middletown-Odessa-Townsend corridor saw the smallest. Hover for the reported range and the tax-bill consequence.

Bars show the reported range of median assessed-value increase for each area group, as published 19-20 Feb 2026 — not point estimates. Sources: Spotlight Delaware analysis, methodology note, Tech Impact Data Lab. Percentages are large because they measure 2024 market value against a 1983 base-year value, not a year-over-year change.
"I don't think that [Tyler Technologies] didn't make mistakes in Sussex or Kent. I think that the mistakes didn't get through there because the county was in charge, but New Castle County chose to wash their hands of any kind of oversight." — Wilmington City Councilwoman Christian Willauer, Spotlight Delaware, 19 Feb 2026

Visualization 4 · Appraisal quality, by the vendor's own numbers

Tyler's report flags Wilmington itself as out of standard

The Mass Appraisal Report (24 Apr 2025) publishes ratio-study statistics for its eight residential models. The International Association of Assessing Officers considers a Coefficient of Dispersion above 15 a failure of uniformity for this property type. Model 3 — the City of Wilmington — scores 22.68. Each bubble is a model; the shaded band is the IAAO acceptable range.

Model detail

Hover a bubble

Bubble area is the number of verified sales used to calibrate that model. Vertical axis is COD (uniformity — lower is better). Horizontal axis is the median assessment-to-sale ratio, where 1.00 means assessments match sale prices.

Tyler's own explanation for Model 3: sold properties in Wilmington were "typically superior compared to the universe of unsold parcels" and "the interior condition of the housing stock is a major driver of value and was not reasonably ascertained during an exterior inspection" (report p.36). Countywide combined COD was 11.88 across 8,890 sales.

Visualization 5 · The scrutiny funnel

From 11,919 commercial parcels to 50 actually re-examined

After Senate Bill 228 became law without the Governor's signature on 11 Feb 2026, the County published exactly how it narrowed the universe of non-residential parcels down to a review sample. This Sankey traces that documented cascade, filter by filter.

Every figure from the County's Explanation of Quality-Control Review Criteria and Selection of Sample (PDF), based on a 28 Jan 2026 query of the assessment system. Separately, one lawmaker said roughly 1,000 commercial properties tripped a quality check; the County has not confirmed that figure (Delaware Online, 30 Jul 2026).
11,500
informal value hearings held by Tyler before certification
~25,000
parcels whose value was revised after tentative notices went out
52% / 65%
share of informal / formal appeals that produced a value change, per Sen. Mantzavinos at the 7 Oct 2025 hearing
$500K
budgeted by Wilmington for its own third-party interior sampling review of over-assessed blocks

Interactive · Bill comparator

What the split rate did to your school tax

Both rate sets below are official and apply to the same post-reassessment value, so the comparison is apples-to-apples: the July 2025 warrant (one rate for everyone) versus the revised August 2025 warrant (split rates) that the courts upheld. Enter an assessed value to see the difference.





County FY2026 rates: residential $0.1575, non-residential $0.2380 per $100, both down from a single $0.8054 rate applied to 1983-basis values (County release). Excludes vo-tech, crossing-guard, light and municipal levies, and any exemption or credit. Not a tax bill — for orientation only. Actual bills: County parcel search.

Accountability · Who is on your 2026 ballot

Everyone in this record who is asking for your vote

Delaware's primary is 15 September 2026; the general election is 3 November 2026. Candidate filing closed 14 July 2026, so the field is locked. Below is every person named in the reassessment record above who appears on a New Castle County ballot — with a profile page setting out exactly what they did, how they voted, and what they said. Filter by race type, then open a profile.

Document library

The underlying record, searchable

Court opinions, the vendor's appraisal report, procurement files released under FOIA, ordinances, tax warrants, hearing notices and video, official FAQs, statements and public-reaction artifacts. Search by keyword or filter by type; every entry links to the original.

Method, caveats and gaps

What this page is — and what it cannot tell you

Assembled 15 August 2026 from public records only. Priority order: court filings and opinions, statutes and bill records, county documents and ordinances, the vendor's own report, then journalism. Where a fact exists publicly only through reporting of a hearing or a social-media post, the outlet is cited as the record rather than the underlying statement.

Percentage changes are not year-over-year. Every "+300%" or "+800%" figure compares a 2024 market value against a 1983 base-year value. A large percentage increase in assessed value does not by itself mean a large tax increase, because rates fell sharply at the same time. Tax burden moved; total county revenue did not (the County committed that FY2026 collections would not exceed FY2025, excluding new construction).

Known gaps in the public record, as of this compilation:

  • No published final report from the joint House/Senate Special Property Reassessment committees; their recommendations surfaced instead as the June 2026 bill package and two working-group resolutions.
  • The County Auditor's review of Tyler's work proceeded without a Council mandate after Resolution 25-150 failed 7-6; no completed public audit report has been posted.
  • The July 2025 Tackett/Toole audit press release survives only in press reproductions and in the County Executive's reference to it.
  • Roll call on Ordinance 25-099 is recorded publicly only as 12-1; the single dissenting vote is not identified in available records.
  • Outcome of Resolution 25-157 (reassessment task force), pulled from the 9 September 2025 agenda, is not established.
  • Parcel-level assessment rolls are public but not published as bulk downloads by the County; the only comprehensive comparison in circulation is Spotlight Delaware's FOIA dataset.
Use it yourself

Citizen action routes

Look up any parcelCounty parcel search

Appeal a valuation — Board of Assessment Review, annual deadline 14 March. BOAR · Formal appeal FAQ (PDF)

File a FOIA requestCounty FOIA portal · request form (PDF) · FOIA@newcastlede.gov

Read what is already releasedReassessment FOIA & RFP page

Watch the hearingsHouse special committee · County Council agendas & video

Check your registration and districtDelaware Dept. of Elections · 2026 primary candidate list