Private RAG Knowledge Base for SMBs with EU Hosting: Cost (2026)

The verdict in three sentences

An engineering consultancy sitting on 10 years of reports, calculation notes and standards can make them searchable in natural language with a RAG knowledge base (retrieval-augmented generation). On the market, a custom project costs 15,000 to 45,000 EUR for 5,000 to 50,000 indexed documents, then 100 to 800 EUR a month to run. Two conditions are non-negotiable: access rights enforced document by document and hosting in the European Union, compatible with GDPR and the EU AI Act.

What RAG changes for an engineering team

RAG does not "guess": it first retrieves the relevant passages from your documents, then the model drafts an answer citing its sources. The engineer can open the cited report and check. That is what sets it apart from a consumer chatbot, which answers from memory.

Project and running budget

At Kolonell, this kind of project falls within our complex custom application grid: 7 to 15 M FCFA and above (10,670 to 22,870 EUR and above), depending on document volume and the number of connected systems (file server, SharePoint, document management). A pilot limited to one department and a few thousand documents can fit the 4 to 7 M FCFA band (6,100 to 10,670 EUR). Maintenance is 35,000, 75,000 or 120,000 FCFA per month (50, 110 or 180 EUR).

Compliance: GDPR, sovereignty and the EU AI Act

• Hosting: vector database, documents and logs hosted in the EU, model called through a European region, with no reuse of data for training.
• Access rights: every returned passage must be filtered by the user's rights. An engineer without access to HR files must never see an excerpt from them, even rephrased.
• EU AI Act: an internal document assistant generally falls under limited risk. Users must be told they are interacting with AI, teams must be trained (the AI literacy obligation has applied since February 2025) and the system must be documented.
• Personal data: reports often contain names of clients and contractors. A data protection impact assessment may be needed depending on volume.

Mini case study

Thomas, technical director of a 30-engineer structural consultancy in Toulouse (illustrative case), estimates each engineer spends 2 hours a week looking for precedents. With RAG cutting that time by 40 %, the team recovers 0.8 hour per engineer per week, about 103 hours a month. At a loaded hourly cost of 55 EUR, the gain is 5,670 EUR a month. Monthly costs: 400 EUR of running costs and 180 EUR of maintenance. Net gain: 5,090 EUR a month. For a 35,000 EUR project, payback comes in about 7 months, not counting the reuse of already validated calculations.

FAQ

Can RAG make up answers?

The risk exists but is reduced: the model answers from retrieved passages and cites its sources. The tool is set to reply "information not found" when no passage passes the relevance threshold, which brings errors below 5 % on factual questions.

How long until it goes live?

Allow 8 to 14 weeks: audit of the document archive, indexing 5,000 to 50,000 documents, access rights setup, then 3 to 4 weeks of testing with a pilot group of 5 to 10 users.

Can we keep the data on our own servers?

Yes, with an open-source model hosted in-house or with a European host. Infrastructure costs then rise to 500 to 2,000 EUR a month depending on the compute needed.

Are drawings and tables usable?

Tables and the text in PDF drawings are. Pure technical drawings are still poorly interpreted in 2026, so title blocks and bills of materials are indexed instead.

Do we need to clean the archive first?

Minimal sorting is enough: remove duplicates and flag obsolete versions. For a 20,000-document archive, plan 2 to 5 days of work on the client side.

Let's scope your project. Tell us your document volume, sources and access rules: we will price a pilot or a full rollout within the 4 to 15 M FCFA grid, with EU hosting and a go-live date. Detailed quote within 48 h. WhatsApp +221 77 596 93 33. Or request your free quote.