Privacy
Sous Zinc asks for an account only from residents who share their summer, and uses no audience measurement tool. This page says which data leaves your browser, what the server keeps, why and for how long.
Data controller
To be completed before launch: the identity and contact details of the data controller. This page must give them even if the legal notice names only the host.
On your device
Your choice of palette (day, night or shade) is saved in your browser’s local storage: it is only used to show the palette you chose and never leaves your device. The cookies described below serve the service you ask for, or are set only at your request: this is why there is no cookie banner.
While you answer the questionnaire, your answers stay in your browser, in a cookie that disappears when you send them or close your browser. The server only stores them when you send them.
During sign-in, whether it succeeds or not, a session cookie holds the state of the attempt on the server and, once you are signed in, keeps you signed in during your visit. It holds only a random identifier and disappears when you sign out or close your browser.
If you tick “Remember me”, a second cookie keeps you signed in for 90 days in this browser. It holds the random identifier of your account, never your email address, its expiry date and a signature that stops anyone from forging it. It is set only with your agreement, given by ticking the box, and disappears when you sign out.
Your account
For your account, Sous Zinc records your email address, the language of the site and the dates of creation, confirmation and last sign-in. It sends you the sign-in and confirmation links by email, through its sending provider. This processing is necessary for the service you ask for (article 6(1)(b) of the GDPR).
If you answer the questionnaire, Sous Zinc records the building where you live, your floor, the orientation of your windows, what protects your home from the heat, and your summer: how hot you felt at home and how often the bedroom was too hot at night. It asks no question about your health or your household. It only asks you to confirm that you are 15 or over, without recording it, because accounts are for people of that age. Until you confirm your address, your answers do not count; without confirmation, they are deleted with the account after 48 hours. The site’s administrators see your account, your home and your answers in the administration area, to check that the service works and to moderate the summaries. This processing is necessary for the service you ask for (article 6(1)(b) of the GDPR).
If you ask for the heat-wave alerts, by ticking the questionnaire box or from My home, Sous Zinc records your request and its date. When Météo-France puts Paris on orange or red heat-wave alert, it writes to you at the start of the alert, then every evening of the alert at 9:30 pm, through its sending provider, and keeps a record of each email sent, the day, the kind of email and the time it was queued, so as never to send it twice. Each email holds a link that lets you stop the alerts without signing in. This processing is necessary for the service you ask for (article 6(1)(b) of the GDPR); you can stop it at any time from My home or through that link.
If you log temperatures, Sous Zinc stores each reading, its time and the room. Only you and the site’s administrators can see them, the latter to check that the service works and to spot and handle an abuse: they are never published, even summed up by building. This processing is necessary for the service you ask for; grouped and without your email address, your readings also help calibrate the estimates after summer 2027, on the basis of Sous Zinc’s legitimate interest.
Sous Zinc publishes summaries of the answers every week, never live: for a building from 5 confirmed dwellings in the same summer, otherwise for its IRIS neighbourhood, otherwise for its arrondissement, under the same rule. A summary says what most respondents reported and gives the number of dwellings as a band (5 to 9, 10 to 19, 20 or more), never exactly. When 5 dwellings of one building are declared within 24 hours, their answers are published only after a check. If you delete your account or a home is excluded from the summaries, the summaries already published change only at the next weekly publication. This publication is based on Sous Zinc’s legitimate interest in informing about the heat of buildings.
Sous Zinc’s emails (sign-in and confirmation links, report confirmations and heat-wave alerts) are sent by Brevo (Sendinblue SAS, 106 boulevard Haussmann, 75008 Paris), a processor established in France.
Error reports
If you report an error, Sous Zinc stores the building, your email address, who you are (owner, resident or other) and your message, to review it and reply to you if needed. It writes to you, through its sending provider, so that you confirm the report: until it is confirmed, it cannot be handled. Only the site’s administrators see your report. An unconfirmed report is deleted after 48 hours, a resolved report one year after it is resolved, and a confirmed report that is still open twelve months after its confirmation. A public note repeats neither your name nor your message. This processing is based on Sous Zinc’s legitimate interest in correcting its pages and offering a right of reply.
Address search
When you type an address, your browser sends it to the IGN geocoding service (Géoplateforme, data.geopf.fr), which receives the text you typed, your IP address and the headers your browser sends, such as its name and version, and sees that the request comes from this site. To find out which of the suggested addresses lead to a building, your browser then sends the Sous Zinc server the identifiers of the suggestions in the national address base, not the text you typed. The server does not keep them. If you press Search without choosing a suggestion, or if JavaScript is off, the Sous Zinc server receives the text and sends it to the IGN itself, and the IGN does not receive your IP address.
The base map
Streets, water and place names come from OpenFreeMap, served through Cloudflare. To load the map tiles, your browser sends them your IP address and the coordinates of the tiles it asks for, that is, the part of Paris you are looking at. Its privacy policy says what it keeps.
On the Sous Zinc server
To prevent mass copying of the building pages, the server counts the building pages opened, together with the questionnaire screens that show a building, from each IP address over one minute, using only the first half of an IPv6 address. A second counter, built the same way, counts the address searches made from each IP address over one minute, to keep the IGN address service’s quota available to everyone. The lookups behind the address suggestions count with the searches. The server keeps each IP address and its count in memory for two minutes at most, and never writes them to the database or to a file.
So that no address receives links in bulk, the server counts the sign-in links requested for each email address, together with the confirmation links sent after a questionnaire, in one counter: three at most in fifteen minutes. It does not keep the address but a fingerprint computed with a secret key, in memory, for fifteen minutes at most after the last request, and never writes it to the database or to a file.
To prevent bulk submissions, the server also counts the questionnaires sent from each IP address: ten at most per hour. It keeps the IP address, reduced in the same way as for the other counters, and its count in memory for one hour at most after the last submission, and never writes them to the database or to a file.
The server counts in the same way the reports sent with each email address: three at most per day, as a fingerprint kept in memory for one day at most after the last submission. It also counts the reports sent from each IP address, reduced as for the other counters: ten at most per hour. It keeps this address and its count in memory for one hour at most after the last submission, and never writes them to the database or to a file.
On the administrators’ sign-in page, the server counts the attempts by IP address, and by the email address typed together with the IP address, to slow down password guessing: five at most in fifteen minutes for an email address typed from one IP address, twenty-five at most for an IP address. It keeps only a fingerprint computed with a key specific to the server, in memory, for fifteen minutes at most after the last attempt, and never writes it to the database or to a file.
Server errors are reported to GlitchTip, an error-tracking tool that Sous Zinc runs on its own server, so they can be fixed: no data leaves that server for this, and each report is deleted after 90 days. These technical reports contain neither your IP address nor whatever follows the question mark in a page address, such as the address you type in a search or the identifiers of the suggested addresses.
Every hour, the server asks Météo-France for the heat-wave warning level of Paris. It sends it no data about you or your visits, and keeps the level of each day, which is not personal data.
The web server logs requests (IP address, page, date, and the headers your browser sends, such as its name and version) for its security. It leaves out whatever follows the question mark in a page address and in the address of the page you came from, so neither the address you type in a search nor the identifiers of the suggested addresses are in its log.
To be completed before launch: how long the host keeps these logs.
To be completed before launch: the name and address of the site’s host.
How long we keep data
- An unconfirmed account, with its answers: 48 hours after it is created.
- Your account, your homes, including those you have left, your answers and your readings: until you delete your account.
- The record of the heat-wave alerts sent: 30 days after the day of the alert.
- The published summaries: when you delete your account, your home leaves them only at the next weekly publication, not at once.
- An error report: 48 hours if it is not confirmed, otherwise one year after it is resolved, or twelve months after its confirmation if it is not resolved.
- An email waiting to be sent, or whose sending failed: it holds your address until it is sent, and for seven days at most after it is queued; deleting your account does not remove it from the queue.
- The counters: in memory, from two minutes to one day after the last request depending on the counter, as described above.
- The questionnaire cookie and the session cookie: until you close your browser; the “Remember me” cookie: 90 days.
Legal basis
The account, the questionnaire, My home, your readings and the heat-wave alerts are necessary for the service you ask for (article 6(1)(b) of the GDPR). The “Remember me” cookie is based on your consent, which you can withdraw at any time (article 6(1)(a)). Sous Zinc relies on its legitimate interest, in the sense of article 6(1)(f) of the GDPR, for the counters, the server logs, the technical error reports, the base map, the address search, the publication of summaries, the calibration and the error reports sent by visitors: to keep the service available and secure, to inform about the heat of buildings and to correct its pages. You can object to the processing based on this interest, as the next section explains.
Your rights
You can at any time access your data, rectify it, erase it, restrict its processing, obtain a copy of it, object to the processing based on legitimate interest and withdraw your consent. From My home, you download all your data (as CSV and JSON), change your answers, delete a reading, stop the alerts and delete your account; for the rest, notably the IP addresses described above (the page, search, questionnaire and report counters and the server logs), write to the data controller. For an error report, write from the email address you used to send it: no account is linked to it, and deleting an account does not delete the reports sent with the same address. You can also lodge a complaint with the CNIL, the French data protection authority.