Build a 10‑year fixed mortgage price from Pfandbrief and Bund yields (Sep 2026): worked example — €400,000 Berlin condo

What we will build and the data sources

This guide shows how to construct a 10‑year fixed mortgage price from market funding yields at the end of September 2026. We start with the 10‑year German sovereign yield (“Bund”) and the 10‑year Pfandbrief yield (covered bond market), then explain the simple add‑up mechanics a lender uses to reach a retail mortgage offer. The two market figures used here are the 10‑year Bund yield (mid‑September 2026) and a 10‑year Pfandbrief reference from market indexes. The Pfandbrief market is the standard wholesale funding source for German mortgage lenders; the industry publishes transparency data and yield indexes. ([investing.com](https://www.investing.com/rates-bonds/germany-10-year-bond-yield-historical-data?source=content_type%3Areact%7Cfirst_level_url%3Aarticle%7Csection%3Amain_content%7Cbutton%3Abody_link&utm_source=openai))

Market numbers (September 2026) and what they mean

Reference numbers used in this worked example (market close values in September 2026):

- 10‑year German Bund (example mid–September 2026): ≈ 3.50 % (daily series and market quotes published publicly). ([investing.com](https://www.investing.com/rates-bonds/germany-10-year-bond-yield-historical-data?source=content_type%3Areact%7Cfirst_level_url%3Aarticle%7Csection%3Amain_content%7Cbutton%3Abody_link&utm_source=openai)) - 10‑year Pfandbrief (index reference for September 2026): ≈ 4.08 % (Pfandbrief index / market overview). ([index.fmh.de](https://index.fmh.de/fmh-iframe/ueberblick/pfandbriefe.aspx?utm_source=openai))

Interpretation: the Pfandbrief yield sits above the Bund yield; the difference is the covered‑bond premium that wholesale investors demand over sovereigns. Lenders issue Pfandbriefe to fund mortgage assets, so Pfandbrief yields are a direct input for bank funding cost. The Pfandbrief market and its statistics are published by the industry association and market index providers. ([pfandbrief.de](https://www.pfandbrief.de/en/statistics/?utm_source=openai))

Step‑by‑step build: from Bund to a lender's funding rate

1) Start with the Bund. For mid‑September 2026 the 10‑year Bund yield used here is ≈ 3.50 %. ([investing.com](https://www.investing.com/rates-bonds/germany-10-year-bond-yield-historical-data?source=content_type%3Areact%7Cfirst_level_url%3Aarticle%7Csection%3Amain_content%7Cbutton%3Abody_link&utm_source=openai))

2) Use the Pfandbrief market as the funding reference. The 10‑year Pfandbrief index value used here is ≈ 4.08 % (September 2026). That is the wholesale funding cost available to institutions that issue covered bonds. ([index.fmh.de](https://index.fmh.de/fmh-iframe/ueberblick/pfandbriefe.aspx?utm_source=openai))

3) Compute the Pfandbrief − Bund spread: 4.08 % − 3.50 % = 0.58 percentage points (58 basis points). That spread tells you the market’s premium for covered bonds over sovereign debt at that maturity. ([index.fmh.de](https://index.fmh.de/fmh-iframe/ueberblick/pfandbriefe.aspx?utm_source=openai))

4) Move from wholesale funding to a retail mortgage rate. A lender adds (a) a borrower/credit margin that reflects borrower risk and LTV, (b) operating costs and servicing, and (c) a small profit margin. Those building blocks vary by lender, by customer credit profile and by the loan‑to‑value. Industry publications and lender pricing panels should be consulted for current retail spreads; this guide sets out the arithmetic so you can plug in live lender margins and get the mortgage rate.

Worked numeric example (how to use the numbers)

Scenario and assumptions (example buyer): purchase price €400,000 (Berlin condo); buyer funds 20 % down (80,000 €), loan principal = €320,000. These financing‑structure choices are illustrative.

Step A — wholesale/funding layer: use Pfandbrief 10y = 4.08 % (index). ([index.fmh.de](https://index.fmh.de/fmh-iframe/ueberblick/pfandbriefe.aspx?utm_source=openai))

Step B — lender retail margin: lenders add a margin above funding. Because retail margins vary by lender and borrower, you must get live quote(s). To show the arithmetic, plug two illustrative margins into the formula (these margin values are examples to demonstrate the calculation; they are not published market quotes):

• Example margin A = 0.50 percentage points → illustrative mortgage rate = 4.08 % + 0.50 % = 4.58 %. • Example margin B = 1.00 percentage point → illustrative mortgage rate = 4.08 % + 1.00 % = 5.08 %.

Monthly payment if the mortgage were fully amortising over 10 years (annuity formula):

- Loan €320,000 at 4.58 % nominal annual → monthly payment ≈ €3,327 (≈ €39,920 per year). - Loan €320,000 at 5.08 % nominal annual → monthly payment ≈ €3,410 (≈ €40,920 per year).

These figures show the impact on cash flow of a 50 bps vs 100 bps additional retail margin above Pfandbriefrate. Do not treat the example margins as a quoted offer — obtain lender quotes for your exact LTV and borrower profile.

Practical checks and next steps

1) Confirm live yields and lender pricing. Pfandbrief and Bund indexes move daily — use the listed sources for the same day you price a loan. ([index.fmh.de](https://index.fmh.de/fmh-iframe/ueberblick/pfandbriefe.aspx?utm_source=openai))

2) Ask lenders for the split: they should show (a) the funding reference they used; (b) the credit/LTV margin; and (c) all fees. If a lender refuses, treat that as a warning. Pfandbrief transparency reports and issuer factsheets explain how covered bonds are used to fund mortgages. ([pfandbrief.de](https://www.pfandbrief.de/en/statistics/?utm_source=openai))

3) For purchase decisions, stress‑test cash flow at several mortgage rates and at alternative amortisation schedules (interest‑only, 20‑ or 30‑year amortisation). This worked example used full 10‑year amortisation simply to show the arithmetic.

4) For tax, legal and individual mortgage selection, consult a German tax adviser or a mortgage broker (Hypothekenvermittler). This article explains the market math but is not personalised financial, tax or legal advice.