Grundheim

Run the Swiss bank affordability stress test (Tragbarkeit) for a property purchase, on the market standard shared by the Swiss comparison calculators (verified against the calculators of major Swiss banks and comparison services, September 2026): imputed 5% interest on the whole mortgage, 1% of the price per year for maintenance and running costs, amortisation of the second mortgage (the part above two thirds of the value) over 15 years, affordable at or below 33% of gross income. Returns whether the purchase is affordable, the housing-cost ratio with its distance to the 33% limit, the full cost breakdown, the first/second mortgage split, and the maximum affordable purchase price for the given income and equity. Individual banks deviate (0.7 to 0.8% running costs, 35 to 40% of net income at some), so present a narrow miss or pass as such. Use for "can I afford a CHF X home" questions. Do not use for the monthly cost or the tranche structure of a mortgage (calculate_mortgage_costs), for rent-versus-buy (compare_rent_vs_buy), or for property outside Switzerland.

calculate_affordability

Compute what a Swiss mortgage actually costs and how to structure it. Returns the first/second mortgage split (the second runs above two thirds of the value and amortises over 15 years), the tranche mix for the chosen strategy with its rates, the real monthly cost (interest, amortisation, maintenance, running costs), the bank affordability check at the imputed 5% rate, a rate-shock stress test both today and once every fixed tranche has renewed, a comparison of all five tranche strategies over ten years, and a ten-year renewal outlook in three rate scenarios. Use for "what does a mortgage on a CHF X property cost per month", "SARON or fixed", "how should I split my mortgage" and rate-rise questions. The rates are the calculator reference rates; call get_mortgage_rates for today's bank-by-bank market rates. For the pure yes/no affordability verdict use calculate_affordability instead. Do not use for property outside Switzerland, for early-exit penalties (estimate_break_penalty), for forward locks (evaluate_forward_mortgage) or for the direct-versus-indirect amortisation decision (compare_amortization_strategies).

calculate_mortgage_costs

Get current or historical Swiss mortgage interest rates (SARON and fixed terms) across major banks and insurers, from grundheim.ch's daily rate comparison. Use for "what are current mortgage rates" or bank-vs-bank rate questions. Data updates about once per day. Do not use to compute what a mortgage costs a household (calculate_mortgage_costs) or whether it is affordable (calculate_affordability); this tool returns market rates only.

get_mortgage_rates

Compare how to split a Swiss mortgage into a 10-year fixed, a 5-year fixed and a SARON tranche over ten years under six weighted SNB policy-rate paths («Zinswelten»: consensus, market pricing, inflation regime, early start, a 2022-style repeat, a franc shock). Returns today's rates and monthly cost per structure, the cost matrix worlds x structures (average monthly, worst year, cumulative ten-year interest, after tax), the weighted expected values, the break-even average policy rate at which fixing and SARON cost the same, a sensitivity table for policy rates 0 to 2 %, and optionally a Monte-Carlo of the 10-year swap over the next 30 or 60 trading days with a jump on the next SNB decision day. Fixed rates are swap plus a margin, SARON is policy rate plus spread plus margin with a 0 % floor. Use for "fix or SARON", "how should I split my mortgage", "what does a 10-year fix cost me if rates rise" questions. The worlds and weights are Grundheim's reading, not a forecast; this is a planning aid, not advice or a bank offer. Do not use for the affordability verdict (calculate_affordability), for today's bank-by-bank rates alone (get_mortgage_rates), or for property outside Switzerland.

compare_tranche_structures

Get key facts for any of the 2122 Swiss municipalities: canton, district, population, postal code, and the cantonal/municipal income-tax multipliers. For Canton Zürich municipalities it also returns official notarized sale-price statistics (median transaction prices for houses and apartments). Use to characterize a location a user is considering. Do not use to compute the tax bill itself (calculate_swiss_income_and_wealth_tax), to rank municipalities (rank_municipalities_by_tax), or for places outside Switzerland.

get_municipality_profile

Rank the municipalities within a Swiss canton by their tax multiplier (Steuerfuss / income tax rate), cheapest or most expensive first. Use for "which municipalities have the lowest taxes in canton Zürich" or relocation-for-tax questions. For Zürich uses the official 2026 Steuerfuss; for other cantons the municipal income-tax rate. Do not use for a household's actual tax amount (calculate_swiss_income_and_wealth_tax) or to compare municipalities across cantons in one call; call it once per canton.

rank_municipalities_by_tax

Get the Swiss residential property price trend over time: the national BFS price index (annual, 2017 onward) and, for a Canton Zürich municipality, the local median sale-price time series for houses and apartments. Use for "how have property prices developed" or "price history in <ZH municipality>" questions. Do not use for the current price level of a listing (benchmark_ask_price, get_market_price_context) or for markets outside Switzerland.

get_price_trend

Calculate the one-time incidental purchase costs (Nebenkosten) of buying Swiss property: land-registry fee (Grundbuch), notary costs, and transfer tax (Handänderungssteuer). These follow per-canton fee schedules that differ widely across the 26 cantons — several levy no Handänderungssteuer while others charge up to ~3.3% — so do NOT estimate them from memory; call this tool for canton-correct reference figures (the effective cost still varies by the individual transaction). Use for any question about closing/incidental/purchase costs, notary, land-registry or transfer tax on a Swiss property purchase. Returns a per-cost breakdown, the total and its share of the price, a cheapest-vs-most-expensive canton comparison, and a prefilled link to continue on grundheim.ch. Do not use for running costs of ownership or the mortgage itself (calculate_mortgage_costs), or for property outside Switzerland.

calculate_purchase_costs

Get current residential asking-price statistics (median CHF per m² and listing counts) from grundheim.ch's live market data — overall, and for a specific municipality when one is given. Use as context for "is this price high" questions, together with get_municipality_profile for location facts. Do not use to search for or list individual properties, to value a specific asking price (benchmark_ask_price), or for markets outside Switzerland.

get_market_price_context

Get official Swiss burglary (Einbruch) statistics per 1,000 residents from federal police crime data: the all-canton ranking, or one canton in focus with its national rank. For canton Zürich it also returns the safest and highest-burglary municipalities. Use for "how safe is canton X" or "burglary rate in Zürich" questions. Do not use for general crime beyond burglary, for individual addresses, or for countries other than Switzerland.

get_safety_statistics

Find craft and construction companies (Handwerker: painters, plumbers, electricians, roofers, carpenters, heating, waterproofing and ~30 more trades) near a Swiss municipality. Takes a free-text need in DE/FR/IT/EN ("Wasser im Keller", "prise électrique", "Bad sanieren") and a place, maps it to trades the way grundheim.ch does, and returns the nearest companies from the official commercial register with distance and, where published, phone and website, plus a link to each company page. Results are register entries, not ratings or recommendations. Do not use for property listings, for places outside Switzerland, for reviews or prices of a specific company, or to contact a company on the user's behalf.

search_tradespeople