Comparable Sales Analysis: What Buyers Are Actually Paying in Your Market

Comparable sales reveal what buyers are actually paying—not what sellers are asking. Learn how to find, evaluate, and apply comp data to determine fair market value and strengthen your negotiating position.

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📚 Part of The OfferGuide Principle Series

This guide explores Pillar 3 of the Four Pillars of Value framework. The Four Pillars provide independent reference points for evaluating any property's fair market value.

The Four Pillars of Value:

  1. County Assessment — The fundamental baseline
  2. Appreciation Baseline — What growth trends suggest
  3. Comparable Sales — What buyers are actually paying (this post)
  4. List Price Psychology — Understanding seller pricing
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County assessments tell you what the government thinks a property is worth. Appreciation baselines tell you what historical growth patterns suggest. But comparable sales tell you something more immediate and actionable:

What are buyers actually paying for similar properties right now?

This is the pillar that most directly reflects current market sentiment. When three similar homes on the same street sold for $440,000, $445,000, and $450,000 in the past three months, that data carries significant weight—regardless of what assessments show or what appreciation models predict.

What Makes a Sale "Comparable"

Not every recent sale qualifies as a useful comp. The goal is to find properties similar enough that their sale prices meaningfully inform your target property's value.

The Core Criteria

Proximity: How close is the comp to your target property?

  • Ideal: Same street or immediate neighborhood (within 0.25 miles)
  • Acceptable: Same subdivision or comparable area (within 0.5 miles)
  • Usable with caution: Similar neighborhood type (within 1 mile)
  • Generally avoid: Different neighborhoods, school districts, or market areas

Recency: How recently did the comp sell?

  • Ideal: Within 3 months
  • Acceptable: Within 6 months
  • Usable with adjustments: Within 12 months
  • Generally avoid: Sales older than 12 months in active markets

Similarity: How similar is the comp to your target property?

  • Square footage: Within 15-20% of target
  • Bedrooms: Within 1 bedroom
  • Bathrooms: Within 1 bathroom
  • Property type: Same type (single-family to single-family, condo to condo)
  • Age: Within 10-15 years
  • Condition: Similar overall condition and updates

The Hierarchy of Comp Quality

When evaluating which comps to weight most heavily:

Tier 1 (Highest confidence):

  • Same street, same floor plan or model
  • Sold within 60 days
  • Nearly identical specifications

Tier 2 (High confidence):

  • Same subdivision, similar size
  • Sold within 90 days
  • Minor differences requiring small adjustments

Tier 3 (Moderate confidence):

  • Same neighborhood, comparable property
  • Sold within 6 months
  • Requires multiple adjustments

Tier 4 (Use with caution):

  • Different neighborhood but similar market
  • Sold 6-12 months ago
  • Significant differences requiring substantial adjustments

Finding Comparable Sales

Source 1: Online Listing Platforms

Zillow, Redfin, and Realtor.com all offer "Recently Sold" filters:

  1. Search your target property's address
  2. Look for "Nearby Sales," "Recently Sold," or "Sold Homes"
  3. Filter by date range (last 3-6 months)
  4. Filter by property type and size range
  5. Review individual sales for details

Limitation: These platforms show what's in public records, which may lag 30-60 days behind actual closings.

Source 2: Your Real Estate Agent

Agents have access to MLS data that includes:

  • More recent sales (often within days of closing)
  • More detailed property information
  • Private remarks that explain unusual sales
  • Pending sales that haven't closed yet

Ask your agent for a Comparative Market Analysis (CMA)—this is standard practice and should include 5-10 relevant comps with detailed breakdowns.

Source 3: County Records

County recorder or assessor websites often show recent transfers:

  • Search "[County Name] recent sales" or "[County Name] property transfers"
  • Filter by date range and area
  • Cross-reference with listing platforms for property details

Source 4: offer.guide Reports

Our reports include user-provided comparable sales analyzed against your target property, with price-per-square-foot calculations and distance measurements.

Analyzing Comparable Sales

Finding comps is step one. Analyzing them properly is where the real value emerges.

Price Per Square Foot

The most useful standardization metric for comparing properties of different sizes.

Calculation:

Price Per Square Foot = Sale Price ÷ Living Area

Example comps for a target property (1,886 sq ft):

AddressSale PriceSq Ft$/Sq Ft
7164 Sweetgrass Blvd$530,0002,120$250
7160 Sweetgrass Blvd$495,0002,134$232
1302 Basketweaver Way$410,0001,768$232

Analysis:

  • Price per square foot ranges from $232 to $250
  • Average: $238/sq ft
  • Applied to target (1,886 sq ft): $238 × 1,886 = $448,668

This provides a market-derived estimate independent of what the seller is asking.

Adjustments for Differences

No two properties are identical. Professional appraisers make adjustments to account for differences between comps and the target property.

Common adjustments:

FeatureTypical Adjustment
Bedroom (per room)+/- $5,000 to $15,000
Bathroom (per full bath)+/- $5,000 to $10,000
Garage (per bay)+/- $5,000 to $15,000
Square footage+/- $50 to $150 per sq ft
Lot size (per acre)Varies significantly by market
Pool+/- $10,000 to $30,000
Age (per decade)+/- $5,000 to $20,000
Condition+/- 5% to 15% of value

Example adjustment:

Target property: 3 bed, 2.5 bath, 1,886 sq ft, no pool

Comp: 4 bed, 2.5 bath, 2,120 sq ft, pool, sold for $530,000

Adjustments:

  • Extra bedroom: -$10,000
  • Extra 234 sq ft: -$23,400 (at $100/sq ft)
  • Pool: -$15,000

Adjusted comp value: $530,000 - $48,400 = $481,600

This adjusted value is more useful than the raw $530,000 for estimating your target property's value.

Identifying Outliers

Not every sale reflects true market value. Watch for outliers that should be excluded or weighted less:

Sales to exclude:

  • Foreclosures and short sales: Often sell 10-20% below market
  • Estate sales: May be priced for quick liquidation
  • Family transfers: May not reflect arm's-length negotiation
  • Investor flips (purchase side): Often below market due to condition

Sales to investigate:

  • Significantly above neighborhood average: Premium features? Bidding war? Buyer overpaid?
  • Significantly below neighborhood average: Condition issues? Motivated seller? Below-market terms?
  • Cash sales: May reflect investor pricing, not retail buyer pricing

When you see a comp that doesn't fit the pattern, dig deeper before including it in your analysis.

Reading Market Patterns

Individual comps tell you about specific transactions. Patterns across multiple comps tell you about market conditions.

Price Trends

Arrange comps chronologically to identify trends:

Example:

DateAddressSale Price
Feb 20251302 Basketweaver Way$410,000
Mar 20257160 Sweetgrass Blvd$495,000
Jul 20257164 Sweetgrass Blvd$530,000

Analysis: Prices appear to be rising over this period. A property worth $450,000 in February might be worth $480,000+ by July. Weight more recent sales more heavily.

Days on Market

How long are similar properties taking to sell?

  • Under 14 days: Hot market, expect competition, limited negotiation room
  • 14-30 days: Active market, some negotiation possible
  • 30-60 days: Balanced market, reasonable negotiation expected
  • 60+ days: Cooling market, stronger buyer negotiating position

If your target property has been listed for 45 days while similar homes sell in 20, that's leverage for negotiation.

List-to-Sale Ratio

What percentage of list price are buyers actually paying?

Calculation:

List-to-Sale Ratio = Sale Price ÷ Original List Price

Example comps:

PropertyList PriceSale PriceRatio
Comp 1$519,000$530,000102%
Comp 2$499,000$495,00099%
Comp 3$425,000$410,00096%

Analysis: Average ratio is 99%. In this market, buyers are paying roughly list price—sometimes slightly above, sometimes slightly below. A list price of $465,000 suggests expecting to pay around $460,000-$470,000 based on market patterns.

Applying Comp Analysis to Your Offer

Step 1: Calculate the Comp-Derived Value

Using your analyzed comps, determine what the data suggests your target is worth:

Methods:

  • Average of adjusted comps: Most straightforward
  • Median of adjusted comps: Reduces outlier impact
  • Price-per-square-foot method: Normalizes for size differences
  • Weighted average: Give more weight to most similar/recent comps

Example:

CompAdjusted ValueWeightWeighted Value
7164 Sweetgrass (most recent)$481,60040%$192,640
7160 Sweetgrass (similar size)$470,00035%$164,500
1302 Basketweaver (same sq ft)$435,00025%$108,750

Weighted average: $465,890

This suggests a fair market value around $465,000-$470,000 based on comparable sales.

Step 2: Compare to List Price

Target list price: $465,000 Comp-derived value: $465,890

Analysis: The list price aligns almost exactly with what comparable sales suggest. This property appears fairly priced based on market data.

Step 3: Factor in Other Pillars

Remember that comparable sales are one of four pillars in The OfferGuide Principle:

  • County assessment may suggest a lower baseline
  • Appreciation baseline may show historical context
  • List price is what you're negotiating against

When comps strongly support the list price (as in this example), aggressive below-list offers become harder to justify with data. When comps suggest values significantly below list price, you have strong negotiating ammunition.

Common Comp Analysis Mistakes

Mistake 1: Using Active Listings as Comps

Active listings show what sellers want—not what buyers are paying. A home listed at $475,000 that hasn't sold is not evidence the market supports $475,000.

Correct approach: Use only closed sales. Pending sales can provide directional information but not confirmed prices.

Mistake 2: Ignoring Condition Differences

Two homes with identical specifications can vary by $50,000+ based on condition. A renovated home with modern finishes is not comparable to a dated home needing updates.

Correct approach: Account for condition in your adjustments, or find comps with similar update levels.

Mistake 3: Insufficient Sample Size

One or two comps don't establish market value—they establish what one or two buyers paid.

Correct approach: Aim for 4-6 quality comps minimum. If you can't find enough similar recent sales, expand your search criteria cautiously and weight those comps less heavily.

Mistake 4: Geographic Mismatch

A comp 2 miles away in a different school district or neighborhood type may not reflect your target's market.

Correct approach: Prioritize proximity. Cross a major road, change school districts, or enter a different HOA, and values can shift dramatically.

Mistake 5: Ignoring Market Direction

Six-month-old comps in a rapidly appreciating market understate current value. Six-month-old comps in a declining market overstate it.

Correct approach: Weight recent sales more heavily and consider market trajectory when interpreting older comps.

How offer.guide Applies This Pillar

When you generate an offer analysis through offer.guide, our system:

  1. Incorporates user-provided comps from your research
  2. Calculates price per square foot for standardized comparison
  3. Measures proximity to verify geographic relevance
  4. Computes comp averages to establish market-derived value
  5. Compares to list price to quantify alignment or divergence
  6. Presents this as Pillar 3 alongside county assessment, appreciation baseline, and list price analysis

The more quality comps you provide, the stronger your analysis becomes.

Key Takeaways

1. Comps show what buyers actually pay—the most direct measure of current market value.

2. Quality matters more than quantity. Three excellent comps beat ten mediocre ones.

3. Adjust for differences. Raw sale prices of dissimilar properties mislead; adjusted values inform.

4. Watch for patterns. Trends in price, days on market, and list-to-sale ratios reveal market conditions.

5. Exclude outliers. Foreclosures, estate sales, and family transfers don't reflect typical market transactions.

6. Combine with other pillars. Comps provide market sentiment; The OfferGuide Principle combines this with three other perspectives for complete analysis.


Continue the Series

This post covered Pillar 3 of the Four Pillars of Value. Continue learning about the framework:


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