The verdict in three sentences
For a housing company with 12,000 flats, a document management system that is just a better shared drive brings little: legal weight comes from evidential archiving with hashes, timestamps and a tamper-evident log, as described in Germany by the BSI's TR-ESOR guideline. The most efficient architecture pairs a certified long-term archive from a specialist with a custom records layer wired into the property management ERP. Kolonell builds that business layer in its medium or complex application bracket, while the certified archive stays a specialist service.
What actually needs archiving
A Berlin housing company, municipal or cooperative, produces and receives tens of thousands of documents a year: housing applications and WBS certificates, leases, handover protocols, rent increase letters, utility cost statements (Betriebskostenabrechnung), arrears files, construction contracts and board minutes. The backlog to migrate reaches 1.8 million documents, part of it still on paper in district offices.
| Document family | Indicative retention | Watch point |
|---|---|---|
| Lease and amendments | Term of lease + 3 years (limitation period) | Link to tenant record in the ERP |
| Handover protocols | Term of lease + 3 years | High-resolution photos, file size |
| Rejected housing applications | Short, often under 1 year | GDPR data minimisation |
| Construction contracts | 5 years after acceptance, longer in practice | Warranty claims |
| Accounting records and invoices | 8 to 10 years under GoBD and the tax code | Link to the finance system |
| Board and supervisory minutes | Long-term or permanent | Agree with the archivist |
Evidential value: what the standards require
In Germany, TR-RESISCAN sets the rules for replacing paper with scans, and TR-ESOR describes how to preserve the evidential value of electronic documents over time: cryptographic hashes, qualified timestamps under eIDAS, sealed audit logs, periodic re-signing. ISO 14641, the international counterpart of the French NF Z42-013, covers the same ground. GoBD adds tax-specific rules: immutability, traceability, machine-readable access for auditors.
A housing company has little to gain from certifying its own archive. The sensible set-up hands final storage to a certified archive provider and builds a business DMS around it that captures, indexes, applies retention, and sends evidential documents to the archive by API.
| Option | Cost, 2026 order of magnitude | What you get |
|---|---|---|
| Enterprise DMS with integration | 40,000 to 120,000 EUR net in year one | Broad features, long configuration, annual licences |
| Certified TR-ESOR archive as a service | 2,000 to 10,000 EUR net per year by volume | Evidential value, no business interface |
| Shared drives and naming rules | Low | No evidential value, no lifecycle |
| Kolonell, medium application | 4,000,000 to 7,000,000 FCFA (6,100 to 10,670 EUR) | Business DMS, indexing, ERP link, workflow |
| Kolonell, complex application | 7,000,000 to 15,000,000+ FCFA (10,670 to 22,870+ EUR) | Adds bulk migration, OCR, tenant portal, disposal |
| Kolonell maintenance | 35,000 to 120,000 FCFA per month (53 to 183 EUR) | Fixes, changes, monitoring |
Scanning the paper backlog, the certified archive subscription and German or EU hosting are priced in the quote.
Project building blocks
- Capture: district office scanners, email intake, documents generated by the ERP, uploads from tenants through a portal.
- Indexing: tenant number, unit number, estate, contract number, read by OCR and checked by staff.
- File plan and retention schedule: each document type carries its retention and disposal rule, signed off with the data protection officer.
- Integration: open the document file from the tenant record in the ERP, with no double entry.
- Transfer to the certified archive: automatic submission of evidential documents and storage of the receipt.
- Access and GDPR: rights by office and role, access log, deletion on expiry.
Mini case study
Need a professional website?
Kolonell builds websites that attract clients, optimized for the Sénégalese market. Free quote in 2 minutes.
Jonas, head of digital transformation at a Berlin housing company with 12,000 flats, counts 900 shelf metres of paper files across headquarters and five district offices. An external records store charges about 18 EUR per shelf metre per year, 16,200 EUR in total. Customer service staff spend an average of 20 minutes a day looking for documents: 40 staff over 210 working days means 2,800 hours a year, roughly 112,000 EUR at a loaded cost of 40 EUR an hour. Halving that time saves 56,000 EUR a year. With a complex-tier business layer at about 20,000 EUR and a certified archive at 6,000 EUR a year, payback comes within the first year.
FAQ
Can we destroy paper originals after scanning?
For most documents, yes, if scanning follows TR-RESISCAN and the files are stored in an archive that preserves integrity. A few documents, such as notarised deeds, should be kept on paper; the retention schedule lists them.
Do we have to scan the whole backlog?
No, most providers digitise live files (current leases, open contracts) and let closed files run down. That usually cuts the volume by 40 to 60 %.
How does the ERP integration work?
By API or file exchange on tenant, unit and contract identifiers. Staff open the document file in one click instead of spending 3 to 5 minutes searching.
Where is the data hosted?
In Germany or the EU, with a provider that meets BSI C5 and encrypts data at rest. Tenant data falls under GDPR, and a data protection impact assessment is advisable.
How long does the project take?
Four to eight months: two months for the file plan and retention schedule, three to four months of development and integration, then a rollout office by office.
Let's scope your project. We define the file plan, the ERP integration and the link to a certified archive with you, for an office-by-office rollout. 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.
