Ten calculators, one backend, 134 pages.

The starting point

Behind eigenheim-finanzierung.de is Eigenheim-Finanzierung & Baufinanzierung Vergleichsportal AG from Lüdenscheid. The company brokers mortgages and is part of the X Capital group. The goal was a pure comparison portal: visitors calculate, compare and send an inquiry. The site shouldn't try to do more than that.

The market is dominated by large portals and brokers that have ranked for years. The domain, by contrast, started without any significant backlinks and had only hosted an older site with 13 URLs. Search engines were the most important channel from day one, so the structure had to be built for SEO before the first page was designed.

And the inquiries needed somewhere to go. The website was set to go live before all partner interfaces were in place. Even so, every inquiry had to arrive cleanly and be ready to process from day one.

Concept and design

Search first, then layout

It started with a concept and SEO strategy: keyword research, analysis of search results and competitors, and the site architecture built from that. Every page has exactly one target keyword and ends with a path to a calculator or an inquiry.

For launch, we deliberately didn't build everything, just the part that brings in inquiries from day one. The wider footprint of city pages, glossary and guides came afterward, planned and rolled out in waves.

• Home page and inquiry funnel
• six pages for financing scenarios, such as follow-up financing, refinancing or mortgages without equity
• calculator overview with the first four calculators
• a page on mortgage rates
• guides, about the portal and legal pages

Trustworthy like a bank, calm like a neobank

Fintech and neobank sites served as references. Petrol is the base color, and orange is reserved for the most important button. Inter is the only typeface, self-hosted. The copy uses the formal German “Sie”, because the audience ranges from their mid-20s to 60.

The hero is a calculator. Choose the type of financing, enter the purchase price, equity and postal code, and the page instantly shows the loan amount, monthly payment and interest rate. The most important button, “Calculate rates”, sits in the navigation of every page, with the toll-free phone number right next to it.

Every page with its own signature

Finance topics quickly turn into walls of text. So we translated the content into sections instead of running copy. Every page gets its own interactive element that makes its topic tangible.

• Refinancing: a notice period calculator under § 489 BGB
• Mortgages: the math from purchase price to monthly payment, expandable step by step
• Mortgage rates: fixed-rate periods from 5 to 20 years shown as a staircase
• For the self-employed: a checklist of 15 documents to tick off
• Without equity: a scale showing how the loan-to-value ratio affects the interest rate

The calculators

Native, not embedded

All calculators run directly on the page, with their own calculation logic and no iframe. That's faster, looks like the rest of the site and gives search engines real content instead of an empty frame. Today there are ten.

• Budget calculator: how much house you can afford
• Closing cost calculator: real estate transfer tax, notary and broker fees by state
• Notary fee calculator: notary and land registry fees calculated exactly under GNotKG
• Repayment calculator: amortization schedule with remaining balance per year
• Annuity calculator: calculate the payment, loan amount or term
• Interest calculator: what a tenth of a percent really costs
• Extra repayment calculator: interest savings with and without extra repayments
• Follow-up financing calculator: new payment after the fixed-rate period
• Early repayment penalty: estimate it in advance
• Rate calculator: sample rates by loan-to-value and fixed-rate period

Checked against the source

In the notary fee calculator, every line item shows its number in the official fee schedule. The fee table is stored as a formula and checked against all 93 values of the official table on every build. In the repayment calculator, the usual repayment rates of 1.5, 2.0 and 2.5 percent can be selected with one click, with 2.0 as the default.

Until interest rates come in through an interface, all calculators show clearly labeled sample rates with a fixed as-of date. Page titles, descriptions and main headings deliberately contain no interest rate figures.

Inquiry funnel and lead backend

Two steps to an inquiry

The funnel at /anfrage/ asks for the project and contact details in two steps, with a honeypot against bots. A dedicated endpoint on Vercel receives the inquiry and passes it on to the backend. Every inquiry carries the page it came from and the page the visitor viewed before that. The contact form feeds into the same system.

A dedicated backend instead of an inbox

Instead of forwarding inquiries by email, we built a dedicated lead backend as a separate application alongside the website. The login is linked in the website footer.

• Next.js with a Postgres database in Frankfurt, accessed through Drizzle
• Login with roles and permissions
• Full-width lead table with search, filters and bulk actions
• Side panel with all details right from the table, plus the complete record with notes and history
• Sales stages as a drag-and-drop Kanban board, with follow-up reminders
• Overview with key metrics and an activity feed
• Handoff to connected partners via interface

The website and backend share no code and are connected only through a lean interface. That way the backend can evolve without touching the website, and vice versa. Before launch, we tested the entire path from form to database record.

Launch and SEO

A launch without lost URLs

On September 24, 2026, the portal went live at eigenheim-finanzierung.de. Eleven URLs from the old site redirect via 301 to the matching new pages. The canonical domain is the one without www, because that's how the old site was indexed. The website and backend run in Vercel's Frankfurt region.

• Sitemap, structured data and a phone number as ContactPoint
• robots.txt that allows AI crawlers, plus an llms.txt

From 22 to 134 pages

When the SEO retainer started, we first rebuilt all existing pages. Plain running text had taken up as much as 77 percent of the page height; afterward, it was zero on most pages. Then came the new pages, in waves, each with a calculation card or tool. After every deploy, IndexNow automatically submits only the pages whose content has changed.

• Real estate transfer tax for all 16 German states, with prices from the official valuation committees
• ten loan amounts from €100,000 to €600,000 with interest rate scenarios
• 16 city pages in NRW and Baden-Württemberg, with prices from the official property market reports
• a glossary of 50 terms, with search and categories
• mortgage rate trends as an interactive chart based on the Bundesbank time series since 1982
• an overview of eight interest rate forecasts from seven sources
• nine guides as real articles with a table of contents, sources and an editorial box

Every number sourced

Mortgages are a topic where wrong numbers do real damage. We backed every fact on the new pages with a source and retrieval date. Along the way, we also spotted errors in the existing content, such as incorrect tax rates for individual states, and corrected them.

A check script reviews every page before it goes live: exactly one H1, no dead links, no horizontal scrolling on mobile, no block of running text over the limit. All 134 pages pass.

The result

Eigenheim-Finanzierung.de has been live since September 24, 2026, 23 days after project kickoff. Every inquiry lands in the dedicated lead backend and can be processed there right away.

The 22 pages at launch have grown to 134, with ten calculators, 50 glossary terms, 16 cities and all 16 German states. The SEO work continues.

Mobile

This is how the website looks on a smartphone.

Metrics

Measured with Google PageSpeed Insights on October 21, 2026. View report

Project details

Client

Eigenheim-Finanzierung & Baufinanzierung Vergleichsportal AG

Industry

Real estate & finance

Year

2026

Services

Concept and SEO strategy, UI/UX design, development, calculator development, lead backend, SEO and content

Technology

Astro, Next.js, Postgres, Vercel