40% of Cobb County homes may be overvalued, O'Connor says

A new O'Connor review says as many as 40% of Cobb County homes may be overvalued in 2026, creating fresh grounds for property tax appeals. The analysis also points to rising commercial assessments in a county where home and business values have climbed even as broader Atlanta-area and national trends diverge.

Why it matters: - Overassessed property can push tax bills higher than the market supports. - The finding gives Cobb County homeowners and businesses a reason to review assessments and consider appeals. - The issue matters more as property values and millage rates keep rising across metro Atlanta.

What happened: - O'Connor said a 2026 study of Cobb County home sales showed as many as 40% of homes may be overvalued. - That is up from 33% of homes believed to be overvalued in 2025. - Cobb County residential values were assessed as rising 4.2% in 2026, after a 3.1% increase in 2025. - Cobb County commercial real estate rose 6.3% in 2026.

The details: - The Cobb County Board of Tax Assessors estimates market value using sales records from the past three years. - O'Connor said those records can lag current market conditions and lead to unequal assessments. - Total Cobb County residential market value reached $109.01 billion. - Homes worth $250,000 to $500,000 made up the largest share, at $46.22 billion after 2.4% growth. - Homes worth $500,000 to $750,000 rose 4% to $32.72 billion. - Homes worth $750,000 to $1 million increased 5.3% to $14.92 billion. - Homes under $250,000 rose just 0.7% to $1.98 billion. - Homes under 2,000 square feet totaled $35.30 billion, after a 3.8% increase. - Homes from 2,000 to 3,999 square feet totaled $59.64 billion, also up 3.8%. - Homes from 4,000 to 5,999 square feet rose 6.3% to $11.77 billion. - Homes from 6,000 to 7,999 square feet increased 7.9% to $1.71 billion. - Homes larger than 8,000 square feet reached $590.10 million, up 7.3%. - About 43% of Cobb County home value, or roughly $46.91 billion, was built from 1981 to 2000. - About 29% was built from 2001 to 2020. - Homes built from 1961 to 1980 accounted for $20.31 billion. - New construction represented just 4%, or $0.55 billion. - Undeveloped land value jumped 354.9% to $215.72 million. - Georgia realtors found Atlanta-area home values declined 0.30% between 2025 and 2026. - Cobb County assessors, by contrast, estimated a 4.20% increase. - Cobb County commercial property totaled $27.45 billion after the 6.3% increase. - Properties valued above $5 million totaled $22.66 billion. - Properties valued from $1 million to $5 million totaled $3.78 billion after 11% growth. - Properties under $500,000 rose 13% to $346.14 million. - Properties worth $500,000 to $1 million rose 12.5% to $662.70 million. - Apartments remained the largest commercial property category, totaling $12.49 billion after a 1.9% increase. - Offices rose 10.8% to $5.43 billion. - Retail and warehouses each totaled about $3.77 billion after increases of 8.3% and 8.8%. - Raw land for commercial use jumped 36.5%. - Hotels declined 0.4%. - The largest share of commercial value was also built from 1981 to 2000, at about 45% or $12.32 billion. - Construction from 2001 to 2020 contributed $6.70 billion after 2.9% growth. - Construction from 1961 to 1980 totaled $5.21 billion after a 6.8% increase. - Raw land rose 16.6% to $2.95 billion. - National commercial property values have fallen 15% since March 2024, according to Green Street Real Estate. - O'Connor said that gap between Cobb County and the national trend could justify appeals. - Apartments totaled $12.85 billion after growing 2.9%. - Garden apartments accounted for $11.87 billion. - Generic apartments rose 36.7% to $533.76 million. - High-rise apartments rose 9.6% to $449.15 million. - Office value was led by properties built from 1981 to 2000, which made up 61% of the total. - Offices built from 1960 to 1981 totaled $539.41 million, or roughly 10%. - Land set aside for office construction rose 25.6% to $403.08 million. - Low-rise offices reached $1.75 billion, high-rise offices reached $2.82 billion, and medical offices reached $864.61 million. - Retail value reached $3.77 billion. - Single-occupancy stores grew 10.9% to $557.07 million. - Community shopping centers reached $901.60 million. - Neighborhood shopping centers reached $878.69 million. - Malls were the only retail category to decline, falling 3.7%. - Warehouses rose to $3.77 billion. - Generic warehouses reached $1.55 billion. - Metallic warehouses reached $1.34 billion. - Mini warehouses reached $880.43 million.

Between the lines: - Cobb County sits in a fast-growing metro area, but the assessment data suggests some properties may not be tracking current market conditions evenly. - The mismatch between local assessments and broader Atlanta-area or national trends strengthens the case for property owners to review tax bills closely. - The strongest gains in commercial value came from offices, land, and smaller-value business properties, while hotels lagged.

What's next: - Homeowners and businesses facing higher assessments are expected to keep filing property tax appeals. - O'Connor is offering its Property Tax Protection Program with no upfront fee and no fee unless it reduces taxes. - The firm says online enrollment takes 2 to 3 minutes. - Property owners can find more information through the company's social media pages.