ISAT methodology

Data source

Bookings, nightly rates and calendars of the units in the Seazone portfolio, from Seazone’s property management system (Sapron): read through the company’s data warehouse for the 12-month series and straight from the system for the live panel. Figures are aggregated before leaving Seazone: no published row carries a code, address or anything that identifies a unit, owner or guest.

Which units are included

• Residential short-term rentals of the portfolio. Hotels, inns, whole buildings and test records are out.
• A night only counts inside the period in which the unit was active at Seazone (from activation to deactivation), so units that left the portfolio do not weigh as empty stock. An inactive record whose deactivation date is earlier than its activation date is left out (a dead record); on a unit active today it is a reactivation.
• When the same unit has more than one record (it left and came back), each night belongs to the record in force on that date: neighborhood, unit type, building and the stabilized/new class come from that record, and the old record's nights are not added to the new one.
• Stabilized unit: active for at least 12 months (activated by the start of the window and not deactivated within it). The main series uses stabilized units only.
• New unit (ramping up): active for less than 12 months. Shown in a separate table, with the same minimum of 10 units, so new entries do not pull the median.

Metrics

• Gross revenue: nightly revenue of non-cancelled bookings, net of coupon discounts, before channel commission (Airbnb, Booking etc.), cleaning fee and owner payout. It is not what the owner receives nor a net return.
• Available night: a night the unit was active and not blocked (by the owner or for maintenance). Occupied night: an available night with a booking.
• Last-minute block: a 1-night block made by the operation on the day itself or the day before closes a night that was for sale until then and did not sell. It still counts as an available (unoccupied) night. Without this rule, a building that closes every vacant night on the day would show occupancy near 100%. Owner, maintenance and longer blocks still take the night out of the available ones.
• Average daily rate (ADR) = gross revenue ÷ occupied nights. Occupancy = occupied nights ÷ available nights. RevPAR = gross revenue ÷ available nights.
• Gross monthly revenue = gross revenue ÷ active months (a month with at least 1 available night).
• Daily rate index: median daily rate of the month ÷ median daily rate of October 2024 × 100 (Oct 2024 = 100), for Brazil and by city.

Statistics

• Each cut publishes the median (P50) and the interquartile range (P25 to P75), not the mean: one luxury unit does not move the median.
• Outliers: within each city, a unit whose daily rate or occupancy falls outside 1.5 times the interquartile range (below P25 − 1.5×IQR or above P75 + 1.5×IQR) is removed before aggregating.
• Minimum of 10 units per published cut. Below that the cut is neither stored nor published: the site shows no figure of it. Every figure is shown with its n (how many units it summarizes).
• Nominal values in current Brazilian reais (R$), not adjusted for inflation (IPCA).

Cuts

Brazil, city, city × unit type, neighborhood and neighborhood × unit type. Unit types: studio (studio or 0 bedrooms), 1 bedroom, 2 bedrooms and 3+ bedrooms. Cities are normalized (no accents, with the state); neighborhood spellings are unified by a lookup table (e.g. Jurerê and Jurerê Internacional stay separate).

Gross annual yield

Gross yield = median 12-month gross revenue of the cut ÷ median asking price of apartments for sale in the same neighborhood and size band (studio or 1 bedroom, 2 bedrooms, 3+ bedrooms) when there are at least 30 comparable sale listings; otherwise the same city and band with at least 30 listings; otherwise the cut has no yield and the reason is stated. Listings come from sale portals (VivaReal and, in Florianópolis, also Seamóvel). Value estimated from sale listings (asking price), not a property appraisal: closing prices are usually lower than asking prices. No costs, taxes or vacancy are deducted.

Coverage

Each run publishes how many units entered the series and how many were active in the portfolio ("N of M units"). The difference is units with less than 12 months of operation (shown as new units), outliers and units in cuts with fewer than 10 units.

Frequency and editions

• Live panel (last 30 days and current month, nights stayed and booked): recalculated every hour.
• 12-month and monthly series: recalculated once a day at 2 pm Brasília time, on a rolling window closed at the last full month.
• Quarterly editions: a frozen copy of the series at the end of the quarter that never changes after publication (the first is the Q3 2026 edition, in Portuguese, with data through September 2026), with analysis and CSV.

Every page shows the date and time of its last update.

Open data and license

Every ISAT page has a CSV with the same figures. Free to use with attribution, under the data terms of use (in Portuguese).

How to cite

"ISAT — Seazone Short-Term Rental Index (ISAT, Seazone portfolio data). Rentu, https://rentu.com.br/en/short-term-rental-index", with the page’s update date. In tables and charts: "ISAT, Seazone portfolio data".

See the ISAT · Metodologia em português