No one should have to bow down to a bad landlord.
RottenApartments is the consumer advocacy platform for San Francisco renters. We combine real tenant reviews with public city data to create the most honest picture of what it's actually like to live in a building — so you can know before you sign, and fight back when things go wrong.
Rate your building. Expose the greed. Hold them accountable.
How RottenScore Works
A single number from 1.0 to 10.0 that reflects real tenant experiences and public city data. Lower is worse. Here's exactly how we calculate it — no black box, no secrets.
Tenants rate on six dimensions (1-5 stars each)
Maintenance, noise, safety, pest control, landlord responsiveness, and value for money. We average these six ratings into a single 1-5 “raw” score per review.
Bayesian average prevents gaming
Instead of a simple average, we use a Bayesian average. This means buildings with only one or two reviews are pulled toward the city-wide average, preventing a single rave (or rage) review from wildly skewing the score. As a building gets more reviews, the score reflects those reviews more directly.
Bayesian Avg = (C x M + Sum of ratings) / (C + N)
Where C = confidence weight (currently 3), M = city-wide mean, N = number of reviews
Map from 1-5 to the 1-10 scale
The Bayesian average (1-5) is linearly mapped to a 1.0-10.0 scale. A raw 1.0 becomes 1.0, a raw 3.0 becomes 5.5, and a raw 5.0 becomes 10.0. This gives us more granularity to distinguish between buildings.
Open Violation Penalty: -0.15 each (max -1.5)
Every unresolved code violation on file with SF DBI subtracts 0.15 points from the score, up to a maximum penalty of -1.5 points (10 violations). These are objective government records — not our opinion. If a landlord fixes the violation and DBI closes it, the penalty goes away automatically.
Score Tiers & Badges
1.0 - 3.0
Serious issues. Multiple violations, poor reviews, or both. Proceed with extreme caution.
3.1 - 5.9
Below average. Some problems reported, mixed reviews from tenants.
6.0 - 7.9
Decent building. Generally positive but with room for improvement.
8.0 - 10.0
Well-maintained, responsive landlord, happy tenants. A good place to live.
Our Data Sources
Every piece of building data on RottenApartments comes from public government records. No proprietary databases, no paid data brokers — just transparent public information that anyone can verify.
DataSF Open Data Portal
San Francisco's official open data platform. We pull building permits, housing inspection records, and complaint histories directly from public city datasets updated regularly.
SF Department of Building Inspection (DBI)
Active code violations, complaint records, and inspection results. Every violation that appears on RottenApartments is a matter of public record filed with DBI.
SF Assessor-Recorder
Property ownership records and ownership transfer histories. This is how we link buildings to their operators and track ownership changes.
Who We Are
RottenApartments was built by renters, for renters. We're a small team of San Francisco tenants who got tired of signing leases blind — moving into buildings with hidden mold, absent landlords, and years of unresolved code violations that nobody warned us about.
We believe housing information should be free, transparent, and community-owned. Landlords have property managers, lawyers, and tenant screening services. Renters deserve tools too.
Renter-first
Every decision is made with tenants in mind
Independent
We don't take money from landlords or brokers
Community-built
Powered by real reviews from real tenants
We are not affiliated with any property management company, real estate brokerage, or landlord association. We do not take any money from landlords or property managers, and we do not charge renters to use this platform.