As of: October 2026
The party responsible for data processing is: Digital Solution Partners GmbH Im Hasenbart 1 8125 Zollikerberg Switzerland kontakt@grundheim.ch
When using our Platform, the following data may be collected:
We use your data for the following purposes:
We only share personal data with third parties when this is necessary for service provision (e.g. payment processors, cloud hosting), or when we are legally obliged to do so. Data is not shared for advertising purposes.
On grundheim.ch, we maintain a public directory of trade businesses so that property owners can find the appropriate trades for a renovation.
Origin of the data: company name, address, registered office municipality and purpose originate from the Confederation's public commercial register (Zefix), accessed via the Confederation's LINDAS platform. Contact details such as telephone, email and website originate, where available, from the Répertoire des entreprises of the Canton of Geneva and from publicly accessible membership directories of trade associations. We derive the assignment to a trade from the purpose entered in the commercial register.
Purpose: We display this information so that people searching can find and contact a business. We do not sell placements, do not sort according to payment and do not sell the data or hand it to third parties for their own use.
Access through AI assistants: the same information shown on the website (company name, address, distance, phone and website) can also be retrieved through our MCP server (see section 12). When someone asks their AI assistant for a business nearby, the assistant receives at most ten entries, each with a link to the business's page. E-mail addresses are never returned there, and a removed entry does not appear there either.
In the case of sole proprietorships, this information may be personal data. We therefore inform affected businesses about their entry as soon as a contact address is available to us.
Your rights: Every business may have its entry rectified, supplemented or permanently removed at any time. Removal takes place without reasons being required, without a user account and permanently; even a subsequent update of our data sources will not restore the entry. To do so, use the link in our message or write to kontakt@grundheim.ch.
Retention: If an entry is removed, we store exclusively the information that this business should not be listed. Without this note, it would appear again during the next update.
We implement appropriate technical and organisational measures to protect your data against unauthorised access, loss or misuse. Data transmission is encrypted (TLS/SSL).
The Platform uses technically necessary cookies for authentication and session management. In addition, we use Google Analytics 4, a web analytics service provided by Google Ireland Limited, Gordon House, Barrow Street, Dublin 4, Ireland.
Google Analytics collects the following data:
Google Analytics is only activated when you explicitly consent via the cookie banner on the Platform. Your choice is stored locally in your browser. Without consent, no analytics cookies are set and no data is transmitted to Google.
Google Analytics uses IP anonymisation (the IP address is truncated before storage). Data is processed on servers in the EU/Switzerland. For more information on data processing by Google, see https://policies.google.com/privacy.
You may revoke your consent at any time by clearing your browser's website data or removing the 'buyer_consent_analytics' entry from local storage (localStorage).
We also operate Plausible Analytics on a self-hosted server (analytics.grundheim.ch, Azure region Switzerland North). Plausible sets no cookies and no persistent identifiers. IP address and user agent are processed only transiently for session attribution and geolocation and are not stored. Because no personal data is persistently stored, Plausible does not require consent.
You have the following rights regarding your personal data:
To exercise your rights, contact us at kontakt@grundheim.ch.
We only store your data for as long as is necessary for the stated purposes or statutory retention periods apply. After deletion of your account, your personal data will be deleted within 30 days, unless statutory retention obligations exist.
We reserve the right to amend this Privacy Policy at any time. The current version is available on the Platform.
This Privacy Policy is governed by Swiss law, in particular the Federal Act on Data Protection (FADP). The place of jurisdiction is Zurich, Switzerland.
Grundheim operates a Model Context Protocol (MCP) server at agent.grundheim.ch through which AI assistants such as Claude or ChatGPT can call our calculators (taxes, affordability, mortgage rates, municipality data, tradespeople directory). Use is anonymous: no account is required and we do not learn the identity of the person using it.
The values you give your assistant (for example purchase price, income, municipality) are sent to our server for the calculation and processed there in memory. We do not receive conversation content. Short links are the exception: when the assistant creates a link to a prefilled calculator on grundheim.ch at your request, we store that link's target address, including the values it contains (such as purchase price, canton or municipality), in our short-link service so that the link keeps working. These entries contain no personal data and are not linked to any person.
For operational and statistical purposes we log technical metadata per call: the tool name, the language, the response time, the time of the call, the identifier transmitted by the client (User-Agent, for example Claude, ChatGPT or the version of our iOS app) and the outcome (success or error). Inputs and results are not part of these logs. Our hosting with Microsoft Azure additionally records technical request data (time, path called, status code, response time and a coarse region of origin derived from the IP address). We additionally send a cookieless usage event to our self-hosted Plausible Analytics instance (tool name, client type, language, outcome) without IP address and without a user identifier. The logs are deleted after 90 days.
Clicks on the "Connect to Claude" and "Connect to ChatGPT" buttons on grundheim.ch are recorded as an event in our web analytics (see section 7, Cookies and tracking) so that we understand how the integrations are used.
The conversation with the assistant itself takes place on the provider's platform (Anthropic PBC for Claude, OpenAI for ChatGPT, Google for Gemini). Which data these providers process, and where, is governed solely by their privacy terms; Grundheim has no influence on this and receives no data from these platforms other than the tool calls described.
You can remove the connection at any time in your assistant's settings. After that, no further calls reach us.
The iOS app «Hypothekarzinsen Schweiz» is operated by Digital Solution Partners GmbH. It does not require an account or registration. On first launch, the app generates a random device identifier that cannot be used to infer your identity.
Interest rate alerts: If you enable notifications, the app transmits this device identifier and the push token issued by Apple to our server so that we can notify you of interest rate changes. Together with your alert settings (provider, term, threshold), these data are stored on our server in the Azure region Switzerland North. If alerts are not enabled, no push data are transmitted.
Usage and diagnostic data: To improve the app, we anonymously collect which screens are accessed, how long a session lasts, as well as crash and performance data (launch time, hangs, memory; provided by Apple’s MetricKit). These data are sent exclusively to our self-hosted Plausible instance (analytics.grundheim.ch) and to our own server, both in the Azure region Schweiz Nord. No third party receives any data, except Apple, which as the operator of the push service receives the push token; there is no cross-app tracking and no advertising identifiers. The data are not linked to your identity.
Calculators: The calculators in the app run mostly on the device. The tax calculator, lump-sum withdrawal tax calculator, pension fund purchase calculator and Renting vs. Buying require the official tax rates and, for this purpose, send the entered values (for example income, assets, municipality, marital status) to our calculation service agent.grundheim.ch. Transmission takes place without a device identifier; the entries are used solely for the calculation, are not stored and do not appear in the logs of the calculation service. The tranche planner additionally retrieves the daily updated swap bands from our server, likewise without personal data.
Tradespeople search: The search runs on your device; for this, the app loads the public directory files from grundheim.ch. If you tap «In meiner Nähe» (near me), the app asks for your approximate location and determines the nearest municipality on the device. The coordinates are neither transmitted nor stored; the municipality remains only on your device, as the last search location. If the collection of usage data is switched on, we transmit anonymously, for the directory's statistics, the trade searched for and the number of results, and additionally the canton and municipality if you typed in a location, but never your search text and never a location from «In meiner Nähe». Your shortlist stays on the device. If you request an editing link for a company, we transmit its business identification number (UID) to our server, which sends the link to the company's address on file with us.
Your control: The collection of usage and diagnostic data can be switched off at any time in the app under «Settings → Analytics». With «Delete my alerts & this device» under «Settings», you permanently remove the device identifier, push token and all alerts from our servers. The interest rate data themselves are retrieved without transmitting any personal data.
Retention: Device identifier, push token and alerts remain stored until you delete them in the app or Apple reports the push token as invalid; they are then automatically deactivated. We retain crash and performance data only for as long as they are needed for error analysis of the relevant app version. Usage statistics are held in Plausible without persistent identifiers.