What Is Sales Comparison Approach?
The sales comparison approach uses comparable sales—what similar properties sold for—to value the subject. Find 3–6 comps, adjust for differences (size, condition, garage, date of sale), and derive a value. For a 1,400 sq ft three-bedroom in Nashville, comps might be $312,000, $298,000, $305,000 adjusted—average $305,000. It's the primary method for owner-occupied residential and supports income approach for rental property. Lenders require it for most appraisals.
The sales comparison approach estimates market value by comparing the subject property to recently sold comparable sales, adjusting for differences in features, condition, and timing.
At a Glance
- What it is: Valuation method using comparable sales with adjustments
- Why it matters: Industry standard for residential; lenders require comp-based appraisals
- Process: Select comps → adjust for differences → reconcile to value
- Best for: SFR, owner-occupied, properties with strong comp data
- Limitation: Doesn't capture income approach value for rentals
How It Works
Comp selection. Same property type, within 0.5–1 mile, similar size (±15%), sold within 6–12 months. Toss outliers. The MLS and county records provide sold data. More similar comps mean tighter value range.
Adjustments. No two properties match. Add or subtract value for: square footage, bed/bath count, garage, pool, condition, lot size, date of sale (time adjustment in moving markets). Appraisers use a grid; investors often use a simpler +/- approach. Document the logic.
Reconciliation. After adjustments, you have adjusted sale prices. Weight the closest comps. The result is your market value estimate. For CMA and appraisals, this is the core methodology.
Real-World Example
Jacob's sales comparison in Birmingham. Subject: 1,620 sq ft, 4 bed, 2.5 bath, 2-car garage, 2004 build. Five comps from MLS:
- Comp 1: 1,580 sq ft, $278,000, 3 months ago → +$3,000 size, -$2,000 time = $277,000 adj
- Comp 2: 1,650 sq ft, $285,000, 5 months ago → -$2,500 size = $287,500 adj
- Comp 3: 1,590 sq ft, $272,000, 4 months ago → +$2,000 size, +$1,000 garage = $275,000 adj
- Comp 4: 1,640 sq ft, $282,000, 2 months ago → -$1,500 size = $283,500 adj
- Comp 5: 1,600 sq ft, $276,000, 6 months ago → +$1,000 size, +$3,000 time = $280,000 adj
Reconciled value: $281,000. Jacob used that for his property valuation and offered $268,000.
Pros & Cons
- Industry standard; lenders and appraisers use it
- Comparable sales reflect actual transaction prices
- Transparent—you can show comps and adjustments
- MLS and county data make it accessible
- Works well for residential with strong comp supply
- Lagging indicator; 6-month-old comps can be stale in fast markets
- Selection bias can justify any price
- Unique properties lack good comps
- For rental property, income approach often matters more
Watch Out
- Cherry-picking: Use all reasonable comps; don't select only those supporting your desired value
- Time adjustments: In rising markets, add to older comps; in falling markets, subtract
- Rental blind spot: Sales comparison values like a house; NOI and cap rate drive rental property value
Ask an Investor
The Takeaway
The sales comparison approach is the backbone of residential property valuation. Use comparable sales, adjust for differences, and reconcile. For rental property, pair with income approach.