Methodology

1. Clustering

Every property is grouped into a cluster — same ZIP code and same room count (e.g. "8700 · 3.5-room") — together with the rental comparables and other tracked properties that match it. Clusters are the unit both rent estimates and cross-property benchmarking are built on; the comparison's "Cluster benchmark" card shows a property against its cluster peers on size, construction year, price/m², and gross yield, plus a detail line per property covering condition, floor, outdoor space, view, orientation, and parking.

Those detail-line fields are extracted from each listing's own research notes/description — not independently verified or newly researched — so a field showing "not stated" or "not researched" means the source material didn't mention it, not that the property lacks that feature. Filling these in more completely (e.g. exact floor number or compass orientation) would need a dedicated pass re-checking each listing, since not every portal states them.

2. Data sources

• Properties: currently or recently listed residential properties, sourced from public listing portals and broker sites. Coverage was originally limited to 4 Gold-Coast-adjacent ZIP codes (8700/8702/8008/8001); as of the 2026-08-30 refresh it was widened to greater Zürich, adding Höngg (8049), Seebach (8052), Alt-Wiedikon (8003), Altstetten (8048), Affoltern (8046) and a second Wiedikon cluster (8045). Some broker listings (new-build projects in particular) don't disclose an exact street address pre-sale — these are marked "address on request", the same convention already used for a couple of the original 8 properties.
• Mortgage rates: published rates and margins from Swiss banks, cantonal banks, insurers, and cooperative lenders, cross-checked where possible against rate-comparison aggregators.
• Rental comparables: asking rents for similar units in the same neighbourhood, plus published market-rent benchmarks, used to estimate a realistic achievable rent per property.

Standing source list for buy and rent screening (as of 2026-08-30): Engel & Völkers, Walde & Partner, Ginesta, newhome.ch, realadvisor.ch, primelocation.com, properstar.com, christiesrealestate.com, immobilier.ch, and comparis.ch. Inizia listings are also monitored, though Inizia's own site doesn't disclose price and isn't used as a price source directly (see §9 of the project log). Homegate and ImmoScout24 have been excluded from this list at Oli's request — both consistently block automated screening (CAPTCHA/bot-detection), so they are no longer checked in any research pass, manual or bulk. This list is maintained going forward — new relevant portals encountered during research are appended to it.

All three are point-in-time snapshots, not live feeds. Rows or providers marked with an asterisk (*) in the financing matrix are carried forward from an earlier research round and have not been reconfirmed in the most recent refresh — treat those numbers as indicative only and confirm directly with the lender.

The Benchmarking page additionally shows 415 properties from a separate, larger one-time bulk scrape of newhome.ch (all ZIP codes 8000–8999, 2026-08-30) — these carry a distinct "Bulk scan" status badge and are not part of the 14 individually hand-researched properties described above: they weren't individually re-confirmed, and only have the fields visible on a search-results page (no floor, condition, orientation, parking, or outdoor space). Their rent estimate and gross yield use the same cluster-based method as §3 below, but drawing only on rent listings from that same bulk scrape — not the 14 curated properties' own rental comps. For this reason bulk-scraped properties are Benchmarking-only and never appear on the Investment or Living pages, which require the full financing research the 14 curated properties have.

3. Rent estimation method

Within each cluster, rent is estimated one of two ways, depending on how much comp data is available:

• Per-m² method (preferred): if a cluster has at least 2 rental comps with a known floor area, their CHF/m²/month is computed and the median taken; this rate is then multiplied by each property's own size. This corrects for the common case where a matching-room-count comp is considerably smaller or larger than the subject property — a flat median of raw rents would otherwise mis-price it.
• Flat median (fallback): if fewer than 2 sized comps exist in the cluster, rent falls back to the plain median of that cluster's comp rents, regardless of size — the same method used throughout earlier versions of this tool.

Which method applied to a given property, and how many comps backed it, is recorded and shown in the comparison's cluster benchmark card. A small tracked set (8 properties) means several clusters still only have 1 sized comp or fewer — the flat-median fallback exists for exactly that case, and its numbers should be treated as rougher estimates than a per-m²-backed one.

4. The calculation cascade

For a given property, lender, fixed-rate term, equity share, and monthly rent, the model runs through:

1. Equity / mortgage split. Mortgage amount = purchase price − equity. Each lender has its own minimum equity share and maximum loan-to-value (LTV); the comparison won't let you select an equity share below a lender's published minimum.
2. First vs. second charge. Most Swiss lenders split the mortgage into a first-rank portion (up to 65% LTV, interest-only, no scheduled repayment) and a second-rank portion (the slice between 65% LTV and the lender's max LTV), which by regulation must be amortised down to 65% LTV — this model assumes straight-line, over 15 years unless the lender's own published amortisation period is shorter.
3. Interest. The selected rate (fixed-term or SARON/variable) applied to the outstanding mortgage balance.
4. Maintenance. A flat 1% of purchase price per year — the standard Swiss banking rule-of-thumb for ongoing upkeep and reserves, not a property-specific quote.
5. Tax effect. Modeled at a flat 28% marginal rate applied to net taxable property income (rent minus interest, maintenance and imputed value where relevant), floored at zero so the model never turns a loss into a subsidy. Your actual rate depends on canton, commune, and personal tax bracket, and can differ substantially from 28%.
6. Net cash flow = rent − interest − amortisation − maintenance − tax effect. Shown both per year and per month.
7. Break-even equity. The comparison separately sweeps the equity share from the lender's minimum up to 50% to find the smallest equity stake at which net cash flow crosses zero, holding rate and rent constant.

SARON and 1-year fixed — availability

SARON (variable rate) is a real, selectable term for 7 of the 11 tracked lenders (UBS, ZKB, Raiffeisen, PostFinance, Migros Bank, Baloise, Glarner KB/Hypomat) — it simply won't appear in the term dropdown when an insurer (AXA, Swiss Life, Helvetia, Zurich Insurance) is selected, since those are fixed-rate only. The comparison defaults to UBS on load specifically so SARON is visible without switching lenders first, and shows a hint under the lender dropdown naming which lenders do/don't offer it. 1-year fixed is not published by any of the 11 tracked lenders — reconfirmed 2026-08-30 directly on UBS's own site, whose fixed-mortgage page currently states a 2–10 year range, not 1–15 as an older search snippet suggested. Rather than fabricate a rate, the comparison shows the aggregator's market-floor reference (≈0.88%, smaller regional banks only) alongside an explicit note that no tracked lender offers it.

Split / mixed-tranche financing

You can split the mortgage into two rate tranches from the same lender — e.g. 50% SARON + 50% 5-year fixed — with a slider controlling the split. The effective interest rate used in the calculation cascade is simply the weighted average of the two tranches' rates; amortisation and the rank1/rank2 LTV split are unaffected, since those depend on the loan-to-value, not on which rate product is attached to which slice. Mixed mode is disabled for interest-only/fixed-equity products (see below), since those don't use the standard rank1/rank2 structure at all.

Special case: interest-only / fixed-equity products

A small number of lender products (e.g. Glarner Kantonalbank's "Hypomat" line) don't follow the first/second charge split at all — instead they require a fixed equity share (currently modeled at 34%) with no scheduled amortisation. The comparison detects these products and switches to that simpler branch automatically; the equity slider locks to the required percentage when one of these is selected.

5. Affordability check (Tragbarkeit) — on the Living page

Separate from the buy-to-rent-out model above, the comparison also offers a standard Swiss owner-occupier affordability check: enter your own annual gross income and it computes Tragbarkeit — the ratio of imputed housing costs to income, independent of any rental scenario.

• Imputed housing cost = mortgage × a standardized 5% calculatory interest rate, plus 1%/yr maintenance, plus any required amortisation (same rank2/15-year rule as the main model).
• The 5% rate is a deliberate bank stress-test convention, not today's actual mortgage rate — it's what Swiss lenders typically underwrite against, so a mortgage stays serviceable even if rates rise. Some developer marketing tools instead use the actual contracted rate (e.g. Inizia's own "Tragbarkeitsrechner" widget uses 1.25%/0.75% for its example 5-year-fixed/SARON split), which produces a lower, more optimistic percentage than a bank would actually apply.
• Belehnung (loan-to-value) = mortgage ÷ purchase price, shown alongside for reference.
• Guideline: Tragbarkeit should generally stay at or below ~33%; some lenders allow up to ~35–36%.

6. Buy to live in it, vs. renting a similar home — on the Living page

Separate again from both the buy-to-rent-out model and the Tragbarkeit affordability check, this compares the cost of buying a property to actually live in against renting a comparable one — the classic Swiss "Miete oder Kaufen" question, modeled on the general approach used by independent comparison sites like moneyland.ch's own rent-or-buy tool.

• Down-payment sweep: the comparison is run across seven down payments from 20% to 50% (the range the user asked for), each showing its own initial investment (the down payment itself — notary fees, transfer tax and other purchase costs aren't included, see §7), mortgage size, annual interest, and annual amortisation. Amortisation drops to zero once loan-to-value falls to 65% or below (35% down payment and above here) — that's the same rank1/65% threshold used throughout this tool, not a new rule.
• Imputed rental value (Eigenmietwert). Swiss owner-occupiers must currently declare a notional rental income on their own home — this model estimates it at 65% of the property's market rent (official cantonal formulas vary, commonly cited as roughly 60–70%; 65% is a simplifying midpoint, not any specific canton's real formula), taxed at the same 28% rate used elsewhere in this tool, net of deductible mortgage interest and maintenance. This whole mechanism is scheduled to disappear: Swiss voters approved abolishing Eigenmietwert in a referendum on 2025-09-28, with the Federal Council confirming the change takes effect 2029-01-01 after a transition period — mortgage interest deductibility is abolished at the same time. This comparison uses today's still-current (pre-2029) rules; the net effect of the 2029 switch will vary by how leveraged you are (more mortgage interest to lose the deduction on vs. more imputed income to stop paying tax on), which is exactly why the down-payment sweep matters here.
• Net yearly saving vs. renting compares, cash-for-cash: (annual interest + maintenance + the imputed-rental-value tax effect) against this property's own cluster market-rent estimate — the same "similar home" rent already used throughout the tool. Amortisation is deliberately excluded from this figure, since it's your own money moving into home equity, not money that's gone the way rent is.
• Opportunity cost of equity. Following the same approach moneyland.ch's own tool takes — money spent on a down payment could otherwise have been invested — an adjustable slider (default 2.5%/yr) lets you set your own assumption for what that capital might otherwise earn. "Total benefit of buying vs. renting" combines the cash saving, the equity built through amortisation, and subtracts this opportunity cost, giving a single figure for the currently selected down payment.
• Not applicable to fixed-equity products (e.g. Glarner KB's Hypomat) — those require a fixed 34% down payment rather than a swept range, so the comparison shows a note instead of a table when one is selected.

7. What the model deliberately ignores

• Transaction costs — notary fees, property transfer tax, brokerage commission, mortgage set-up fees.
• Renovation reserves beyond the flat 1%/yr maintenance assumption.
• Vacancy risk — the model assumes the unit is rented every month at the selected rent.
• Value appreciation or depreciation of the property itself.
• Canton- and commune-specific tax rules beyond the flat 28% approximation (imputed rental value rules, deductible mortgage interest caps, wealth tax, etc. all vary).

8. Update cadence

Full research refreshes (new listings, re-confirmed rates, new rental comparables) happen periodically, by hand. Separately, a lightweight automated nightly check re-publishes this website whenever that underlying research data changes — it does not perform any new research itself. See the About page for more on how the two fit together.