The verdict in three sentences
For a Berlin firm managing 900 rental units and 25 WEG condominium associations, established German Hausverwaltung software costs roughly €1 to €3 per unit per month, about €11,000 to €32,000 a year, while a custom platform from a German agency typically costs €60,000 to €150,000 (2026 ballpark), delivered in 3 to 5 months. Most of the return comes from automated rent demands and SEPA direct debit collection, which cut arrears by 30 to 50% depending on the portfolio. A live owner portal with statements and payouts becomes a sales argument to win mandates.
Where spreadsheets and legacy tools break
At 900 units, spreadsheets and ageing desktop software struggle: multiple versions, manual bank reconciliation, late dunning. On the WEG side, Hausgeld calls, the annual Wirtschaftsplan and Jahresabrechnung under the 2020 WEG reform, and the annual Betriebskostenabrechnung for tenants keep two accountants fully busy every spring.
Owners, many of them investors living abroad, call to ask whether rent arrived and when it will be paid out. Each call costs time and strains the relationship.
| Process | Today (900 units, 25 WEGs) | With dedicated software (2026 estimate) |
|---|---|---|
| Rent demands | Standing orders, manual exceptions | SEPA mandates, automatic monthly run |
| Collection | Transfers reconciled by hand | Bank feed matched automatically |
| Dunning | Case by case, often after 30 days | Automatic sequence at D+3, D+10, D+20 |
| Arrears at 30 days | 5 to 8% of units | 3 to 4% targeted |
| Owner payouts | Manual calculation, 10 to 20 days late | Automatic statement, fixed payout date |
| Service charge statements | 2 accountants full time for weeks | Generated per cost key in days |
Off-the-shelf or custom, cost by module
German vendors such as Domus, Haufe PowerHaus, Karthago, immocloud or Casavi cover WEG and rental administration well. Custom makes sense when you need your own owner portal, tenant app, integrations with a craftsman marketplace or a specific reporting model. Below, a typical module breakdown at German market rates in 2026.
| Module | Content | Market cost (2026 ballpark) |
|---|---|---|
| Rental management | Units, leases, tenants, rent indexation (Indexmiete) | €15,000 to €30,000 |
| SEPA and bank feed | Direct debit mandates, automatic matching | €6,000 to €15,000 |
| Dunning and arrears | Letter and email sequences, legal handover | €4,000 to €9,000 |
| WEG administration | Shares (MEA), Wirtschaftsplan, Hausgeld, reserves, meetings | €15,000 to €40,000 |
| Owner and tenant portal | Statements, payouts, documents, repair requests | €10,000 to €30,000 |
| Accounting and exports | Trust accounts, DATEV export | €10,000 to €26,000 |
| Criterion | German vendor software | Custom (German agency) |
| Upfront cost | €2,000 to €10,000 onboarding | €60,000 to €150,000 |
| Recurring cost (900 units) | €11,000 to €32,000 a year | Maintenance and hosting, 10 to 15% of build per year |
| Time to go live | 6 to 12 weeks | 3 to 5 months |
| Owner portal | Standard, vendor branding | Your brand, your features |
| 5-year cost (median scenario) | About €110,000 | About €140,000 to €160,000 |
Median scenario: €2 per unit per month off the shelf (900 × 2 × 12 = €21,600 a year, about €110,000 over 5 years) against a €100,000 build and €10,000 a year of maintenance. Custom only wins if the portal and integrations bring new mandates.
Kolonell prices custom applications on a fixed grid in FCFA and EUR: a platform of this scope sits in our complex tier, 7,000,000 to 15,000,000+ FCFA (10,670 to 22,870+ EUR); a first release limited to rentals and collection can fit the medium tier, 4,000,000 to 7,000,000 FCFA (6,100 to 10,670 EUR). Maintenance runs 35,000, 75,000 or 120,000 FCFA a month (53, 114 or 183 EUR). At that price point, the 5-year comparison shifts clearly. Exact scope is set in the quote.
Mini case study
Jonas, managing director of a Berlin property management firm, runs 900 units at an average rent of €950, €855,000 collected each month. His fee is €28 per unit per month, about €25,200.
Today 6% of rent is more than 30 days late, €51,300. If SEPA debit and automatic dunning bring that down to 3.5%, €21,375 more is collected on time every month, steadier cash for owners and fewer complaints.
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Redeploying one of two accountants to winning new mandates is worth about €5,000 a month. Ten extra units under management add €280 a month in fees. For a €100,000 build, a saving of €5,000 a month plus new mandates pays back in under 20 months.
FAQ
Do tenants accept SEPA direct debit?
Most German tenants already pay by standing order or debit. With a SEPA mandate collected at lease signing, 70 to 85% of rent moves to direct debit within 6 months.
Can we migrate from Domus or Karthago?
Yes, through exports. Migrating 900 units, leases and 12 months of history takes about 3 weeks, including balance checks.
Does the WEG module handle owners' meetings?
It prepares invitations, attendance lists and minutes, and counts votes by share, including hybrid meetings allowed since the 2020 reform. Expect 2 to 4 days of work saved per meeting.
Can owners abroad see their account?
Yes, the owner portal shows rent collected, costs, works and payouts on desktop or mobile, from any country, in German or English.
How fast can a first release go live?
Rental management with SEPA collection can be live in 8 to 10 weeks, with WEG administration and the portal following within 2 months.
Let's scope your project. We take your unit and WEG files, define collection and the owner portal, and plan go-live within 3 to 5 months. Detailed quote within 48 h. WhatsApp +221 77 596 93 33.
Mohamed Bah
Fondateur, Kolonell
Passionate about digital and entrepreneurship in Africa, Mohamed has been helping Sénégalese businesses with their digital transformation since 2020. Founder of Kolonell, he believes every SME deserves a professional and accessible online présence.
