Collin Value

321 St Mark Ln, Prosper, TX 75078

2,847 sqft, built 2015, in Tanner's Mill Phase 1C. Appraised at $730,463 for 2026.

Collin County account 2707087

Small or uncertain difference

about $2,000

8 similar homes nearby point to a value about $2,000 lower than yours, a small or uncertain difference.

Appraised value$730,463
Similar homes$728,945
$1,518 gap · bars start at $0

How sure: High · 8 similar homes (5 shown below) · public records only

Appraised value
$730,463
Tax year 2026
Living area
2,847 sqft
$257 per sqft
Year built
2015
Homestead
Yes
Owner-occupied exemption on file

Why we think so

Unequal assessment

Weak

5 of 8 similar homes are assessed lower per square foot. Their similarity-weighted median is $256.04/sqft, which supports a value of $728,945.

Compare this assessment

Start with the county value and property facts, then review appraisal comps, recent sales, and prior-year changes to decide whether the assessment is worth challenging. The comps on this page are free to review; email sign-in is only used to save a printable report.

For nearby context, browse ZIP 75078, Tanner's Mill Phase 1C, Celina, and Prosper assessment pages.

Protest deadline

The 2026 protest deadline was . The 2027 protest deadline is . 2027 notices usually arrive in April.

Deadline rule: May 15, or 30 days after your notice of appraised value is mailed, whichever is later. A deadline on a weekend or holiday moves to the next business day. Evidence is reviewed by the Appraisal Review Board (ARB). Dates checked against the official source.

Assessment snapshot

These public CCAD records highlight what may be worth checking before you file.

  • Assessment changeThe appraised value decreased 1.3% from $740,189 in 2025 to $730,463 in 2026.
  • Appraised value per square footThe current public record shows about $257 per square foot before any comparable-property adjustments.
  • Nearby comparison areaThis page starts the equity review with public records for the Tanner's Mill Phase 1C neighborhood and ZIP 75078.
  • Neighborhood value signalAmong 304 residential records in the same neighborhood, the average appraised value is about $224 per square foot.
  • Area year-over-year signalNearby residential records with prior-year values moved about -1.5% on average.

Comparable assessments

Showing 5 of the 8 similar homes in this property's equity comparison, from public appraisal records.

  • 1520 Bainbridge Ln, Prosper, TX 75078
    2,819 sqft | $256/sqft | built 2018 | Similar size (2,819 vs 2,847 sqft); Similar age (2018 vs 2015); Similar lot size (10,800 vs 10,890 sqft)
    $721,770
  • 281 Andover Ln, Prosper, TX 75078
    2,804 sqft | $257/sqft | built 2018 | Similar size (2,804 vs 2,847 sqft); Similar age (2018 vs 2015); Similar lot size (10,878 vs 10,890 sqft)
    $720,857
  • 240 Andover Ln, Prosper, TX 75078
    2,766 sqft | $269/sqft | built 2019 | Similar size (2,766 vs 2,847 sqft); Similar age (2019 vs 2015); Similar lot size (10,878 vs 10,890 sqft)
    $745,200
  • 1461 Middleton Ln, Prosper, TX 75078
    2,917 sqft | $261/sqft | built 2019 | Similar size (2,917 vs 2,847 sqft); Similar age (2019 vs 2015); Similar lot size (11,060 vs 10,890 sqft)
    $761,005
  • 221 St Mark Ln, Prosper, TX 75078
    2,896 sqft | $241/sqft | built 2015 | Similar size (2,896 vs 2,847 sqft); Built same year (2015); Similar lot size (10,890 vs 10,890 sqft)
    $699,004

Recent comparable sales

Sales selected by similarity to the subject property. Texas is a non-disclosure state, so these MLS-listed sales are supplemental evidence.

  • 1521 Brush Creek Rd, Prosper, TX 75078
    September-28-2026 | 2,770 sqft | $195/sqft | built 2012 | Similar size (2,770 sqft); Similar age (2012); Sold after the valuation date
    $539,000
  • 720 Hampshire Dr, Prosper, TX 75078
    September-1-2026 | 2,662 sqft | $253/sqft | built 2015 | 6% size difference (2,662 sqft); Similar age (2015); Sold after the valuation date
    $673,000
  • 1618 Gardenia St, Prosper, TX 75078
    August-13-2026 | 2,976 sqft | $215/sqft | built 2018 | Similar size (2,976 sqft); Similar age (2018); Sold after the valuation date
    $639,900
  • 1221 Amistad Dr, Prosper, TX 75078
    July-23-2026 | 2,818 sqft | $195/sqft | built 2006 | Similar size (2,818 sqft); Moderate age difference (9 years older); Sold after the valuation date
    $549,000
  • 1951 Harvard Ave, Prosper, TX 75078
    August-18-2026 | 3,066 sqft | $294/sqft | built 2019 | 8% size difference (3,066 sqft); Moderate age difference (4 years newer); Sold after the valuation date
    $899,900

Public appraisal comparison for 2026. Prepared . Appraisal source: Collin Central Appraisal District. Sales data checked in this snapshot: . Matches consider available size, age, location and property characteristics. How comparisons work.

Value history

Down 1.3% in 2026 from 2025.

Appraised value by tax year, with the change from the previous year listed
Tax yearAppraised valueChangeChange %
2026$730,463−$9,726−1.3%
2025$740,189−$23,764−3.1%
2024$763,953+$19,706+2.6%
2023$744,247+$101,848+15.9%
2022$642,399+$194,733+43.5%
2021$447,666+$30,791+7.4%
2020$416,875——
6-year total+$313,588+75.2%