• GAEB-LV
    • Position
    • Teilleistung
    • Titel
    • Mengenansatz
  • IFC / BIM
    • IfcWall
    • IfcSlab
    • IfcBeam
    • IfcSpace
  • Ökobaudat
    • GWP
    • EPD
    • Lebenszyklus
    • Datensatz
  • Cost data
    • Kostenkennwert
    • Kostengruppe
    • Standardposition
    • KG 300
  • Rohbau
    • Bodenplatte
    • Stütze
    • Geschossdecke
    • Fundament
  • Brandschutz
    • Brandabschnitt
    • Entrauchung
    • F90
    • Sprinkler
  • Bewehrung
    • Betonstahl
    • Bewehrungsmatte
    • Bügel
    • Stabstahl
  • Trockenbau
    • Ständerwand
    • Gipskarton
    • Abhangdecke
    • Vorsatzschale
  • TGA
    • Lüftung
    • Heizung
    • Sanitär
    • Elektro
  • Estrich
    • Zementestrich
    • Anhydritestrich
    • Dämmschicht
    • Randstreifen
  • Mauerwerk
    • Kalksandstein
    • Ziegel
    • Porenbeton
    • Mörtel
  • Dämmung
    • Mineralwolle
    • EPS
    • Perimeterdämmung
    • WLG 035
Vertical Foundation Model · API

The embedding API for the construction industry

flinq is a cross-modal embedding model for the European construction industry. It brings heterogeneous construction data such as BIM models (IFC), tenders (GAEB), manufacturer products, construction-site images and further construction-project data together in one shared semantic space. Access is via an API.

embeddings.sh
curl https://api.flinq.ai/v1/embeddings \
  -H "Authorization: Bearer $FLINQ_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{
    "model": "flinq-embed",
    "input": "Stahlbeton C25/30, Bodenplatte d=25 cm"
  }'

Conceptual example. Runnable examples live in the docs.

Available as a cloud API, optionally on-premise (GDPR-compliant)

+30%

better product retrieval than OpenAI

nDCG 0.78 vs. 0.60

ρ 0.71 #1

understands units of measure better than the whole field

vs. ρ 0.57 (best model in the field)

83%

recognises components by their 3D shape

82.9% accuracy; text-only models: 6.3%

Supported by partners and programmes from the ecosystem.

What flinq reads

One model for all construction data, one shared vector space

flinq reads different kinds of construction data, each in its common file formats, and maps them into one shared vector space. Semantically similar objects sit close together in it, regardless of data type, format and source.

Common construction file formats, each with the construction data types it carries, are embedded by one cross-modal model into a shared vector space.
GAEB Bills of quantities, Line items
IFC BIM models, Building elements, 3D geometry
JPG / PNG Site photos, Plans
PDF Tender texts, Datasheets, Standards
CSV Cost data, Manufacturer products
flinq embedding model cross-modal
Shared vector space format- and source-independent

Cross-modal: a bill-of-quantities line item and the matching IFC component sit on nearby vectors, searchable across formats and sources.

The advantage

Why an embedding model?

For search, matching and RAG over construction data, an embedding model has clear advantages over a generative LLM — in cost, speed and reliability.

Up to 100× cheaper than running an LLM for the task

You embed each object once and store the vector. Search and matching are then pure vector math — no costly model call per query like an LLM.

Real-time answers, even across millions of objects

Vector search over precomputed embeddings returns in milliseconds. An LLM call takes seconds.

Reproducible, defensible results

Same input, same vector — every time. Traceable for costing and tenders, where LLM output varies.

No hallucination

Embeddings retrieve real, existing objects — an actual bill-of-quantities item, a real product — rather than inventing an answer.

Fewer false matches, less rework

Trained on construction data: BauSatz nDCG 0.78 vs 0.60. Higher domain accuracy saves manual correction.

See the benchmark

One integration, many features

The same vectors power search, matching, RAG, deduplication and clustering — several features from one embedding call.

Connect data across format boundaries

Match a bill-of-quantities item, an IFC component and a datasheet cross-modally — connections that were previously manual or impossible.

Your data stays in the EU

GDPR-compliant in the EU, on-premise on request — without a detour via a US LLM provider.

Cost comparison against generative LLMs on retrieval and matching tasks; depends on the model and query volume.

Access

Access via an HTTP API

Access to the model is via an HTTP API. A request embeds one or more construction objects, and the response returns the corresponding vectors.

POST /v1/embeddings
{
  "model": "flinq-embed",
  "input": [
    "Stahlbeton C25/30, Bodenplatte d=25 cm",
    "Bewehrungsstahl BSt 500 S, Mattenbewehrung"
  ]
}

A request embeds a bill-of-quantities line item.

200 OK · application/json
{
  "model": "flinq-embed",
  "data": [
    { "index": 0, "embedding": [0.0131, -0.0427, 0.0588, ] },
    { "index": 1, "embedding": [0.0204, -0.0119, 0.0731, ] }
  ]
}

The response returns the vector and the model id. Vector truncated.

These are conceptual examples that show the format. The full reference and runnable examples live in the docs.

Go to the API reference
What you build

Applications made possible with flinq

On the embedding API you build search, matching and RAG applications over construction data. The examples below show one possible workflow per application. These are applications made possible with flinq, not products flinq ships.

01

LV matching

Match bill-of-quantities line items across projects and catalogues, even when wording differs.

Relevant for TradesConstruction firmsWholesalersManufacturers

A GAEB file from an external tender and the internal product catalogue are embedded, stored in a vector database and matched to one another via the LV-matching function. The result is matched line items with a similarity score.
GAEB file External tender GAEBPDF
Internal product catalogue Your positions CSV
LV matching Function
Embedding
POST /v1/embeddings
POST /v1/embeddings
{
  "input": "Cement screed CT-C25-F4, 60 mm",
  "model":  "flinq-small"
}

Conceptual example. Runnable code in the docs.

Vector database
Stored vectors
IDSourceDim
vec_8a1fBoQ item 01.401024
vec_3c2bIfcWall1024
vec_9d70Datasheet1024
Output
Example output
Line itemMatchScore
Cement screed 60 mmScreed CT-C25-F40.94
Drywall GK 12.5Gypsum board wall F900.88
Rebar Q335AReinforcing mesh0.86
02

Early-phase cost prediction

Derive cost figures from semantically similar line items and reference projects that have already been costed.

Relevant for Planners/ArchitectsConstruction firms

Reference objects are embedded and stored in a vector database; from these an ML model is built. A new project is embedded individually and scored by the same model. The result is a cost figure per square metre.
Reference objects External or internal
Embedding Single object
ML model Trained on references
Embedding
POST /v1/embeddings
POST /v1/embeddings
{
  "input": [ "Office building, 4 floors, KG 300",  ],
  "model": "flinq-small"
}

Conceptual example. Runnable code in the docs.

Vector database
Stored vectors
IDSourceDim
vec_8a1fBoQ item 01.401024
vec_3c2bIfcWall1024
vec_9d70Datasheet1024
New project
Project attributes
AttributeValue
TypeOffice building
Floors4
GFA3,200 m²
Cost groupKG 300
Output
Example output (cost figure)
Reference projectSimilarity€/m²
Admin building Ulm 20230.911,840
Office Stuttgart 20220.871,760
Prediction (weighted)1,805
03

RAG & knowledge management over construction data

Retrieval-augmented generation for company-wide knowledge management: search standards, bills of quantities and project documents with reliable hits.

Relevant for Planners/ArchitectsTradesConstruction firmsWholesalersManufacturers

Internal documents are embedded and stored in a vector database. For a search query, the RAG-retrieval function delivers the most relevant sections to the connected language model, which produces a grounded answer.
Internal documents Your files PDFFotoIFCtxt
LLM Your language model
Output Grounded answer
Embedding
POST /v1/embeddings
POST /v1/embeddings
{
  "input": "Acoustic insulation in drywall",
  "model": "flinq-small"
}

Conceptual example. Runnable code in the docs.

Vector database
Stored vectors
IDSourceDim
vec_8a1fBoQ item 01.401024
vec_3c2bIfcWall1024
vec_9d70Datasheet1024
RAG retrieval
Retrieved sections
SourceSectionScore
DIN 4109-1Sound insulation in buildings0.92
Project file A12Partition walls 1st floor0.81
Tender textStud wall GK0.79
Search query
POST /v1/embeddings
POST /v1/embeddings
{
  "input": "How is sound insulation in drywall regulated?",
  "model": "flinq-small"
}

The query is embedded like the documents and matched over the vectors.

Working examples with real code live in the docs.

More applications

Further applications built on the same embeddings. Filter by audience.

Find the relevant DIN standards

flinq matches your tender text against your own collection of standards and surfaces the relevant DIN standards.

Planners/ArchitectsTradesConstruction firmsManufacturers

Product search and comparison

flinq searches and compares manufacturer products by technical specification and compatibility.

Planners/ArchitectsTradesConstruction firmsWholesalersManufacturers

In progress

Quantities and costs from the BIM model

flinq reads building elements and their quantities directly from the IFC model, as a basis for take-off, costing and billing.

Planners/ArchitectsConstruction firms

Bid comparison (price mirror)

flinq recognises which line items across different bids describe the same work, even when the wording differs, for a real price comparison.

Planners/ArchitectsConstruction firms

Calculation and calculation checking

flinq prices tendered line items using comparable line items from your own project history or external cost databases.

TradesConstruction firms

In progress

From a photo to the product or line item

From a photo of a component, flinq finds the matching product in a catalogue or the corresponding bill-of-quantities item.

TradesConstruction firmsWholesalersManufacturers

Equivalent alternatives on supply shortages

If a product is unavailable, flinq finds technically equivalent alternatives from the range.

TradesConstruction firmsWholesalers

In progress

ETIM/ECLASS classification

flinq classifies products automatically by ETIM or eCl@ss from their description text.

WholesalersManufacturers

Consolidate the product catalogue

flinq detects duplicates and equivalent products from different manufacturers and helps clean up the catalogue.

WholesalersManufacturers

Visibility in tenders

flinq shows which line items your products fit, and where the product description does not yet match the language of tendering.

Manufacturers

These are examples of what is possible with the model. We are continuously working on more. Try it out and read more in the docs.

Get started in the docs
Benchmark

BauSatz: flinq small (0.6B) vs. the field

flinq small is a single 0.6B model. On the BauSatz benchmark it leads on six of eight tasks against larger, zero-shot models.

Product retrieval (nDCG, ×100)
  • flinq small 78.4
  • OpenAI 59.5
  • Gemma2 58.6
  • Qwen3-8B 56.8
  • Mistral 40.3
  • BGE-M3 36.8

Shown is the primary metric per task, ×100. Higher is better. flinq small is the best of v9b/v10. The comparison models are zero-shot. Source: BauSatz public leaderboards, June 2026.

Primary metric per task, ×100. Higher is better. Bold: best model per row.
Task flinq smallOpenAIQwen3-8BMistralGemma2BGE-M3
Product retrieval 78.459.556.840.358.636.8
Unit semantics 70.955.858.752.557.848.6
Spec reranking 78.572.664.970.761.868.9
IFC name matching 71.213.322.219.113.549.7
Trade clustering 36.133.131.329.130.524.3
Equivalence pairs 97.196.196.196.196.196.1
Section classification 72.871.573.260.772.469.5
Position matching 85.287.185.787.286.186.9
Methodology and full results
Deployment and trust

As a cloud API or on-premise

flinq is available as a cloud API and, on request, on-premise. Operation is GDPR-compliant and hosting is in the EU.

Cloud API

Direct access via the hosted API. No infrastructure to run yourself.

On-premise

On request, in your own data centre or VPC. Your data stays in your environment.

GDPR-compliant

Data processing follows the requirements of the GDPR.

EU hosting

The hosted API runs in the EU.

Team

The team behind flinq

flinq is built by a team with backgrounds in architecture, BIM, machine learning and construction economics.

Valentina Mayer-Steudte

Valentina Mayer-Steudte

Co-Founder, CEO

Company leadership, strategy & brand

M.Sc. Architecture: strategic planning, BIM, business development, branding.

Experience: Co-Founder Wertstudent, Bez+Kock Architekten, cruu architecture (BIM)

Matthias Hornung

Matthias Hornung

Co-Founder, CTO

Technical architecture, ML integration & systems

M.Sc. ITECH and M.Sc. Architecture: BIM, graph ML, robotics & software.

Experience: Design-to-Production, Transsolar, Blocher und Partners/Schwarz Architekten

Lukas Simon

Lukas Simon

Co-Founder, CPO

Product strategy, data pipelines & sales

cand. M.Sc. Economics: data analysis, financial modeling, process optimization.

Experience: Mercedes Benz, ZEW

News & updates

Latest developments

Stay up to date with new features, insights and best practices.

Event 2 July 2026 · 2 min

flinq at the ZIA PropTech breakfast at S-TEC

Invited by the ZIA at S-TEC and Fraunhofer IAO: the conversations confirmed that companies are not looking for yet another off-the-shelf tool, but technology that understands their workflows and fits in. An announcement on this follows in the coming weeks.

Read on LinkedIn
Event 1 May 2026 · 1 min

flinq at the TGA Fachforum in Viega World

Two intense days in Attendorn: Lukas Simon pitched how flinq supports AI-driven tendering in building services (TGA). A clear takeaway — manufacturers and wholesalers want to match line items automatically too.

Read on LinkedIn
Event 12 March 2026 · 1 min

flinq at “Bauindustrie meets Startups 2026” in Munich

In dialogue with the board and members of the Bavarian Construction Industry Association: construction meets its challenges best with openness to technology and a collaborative spirit of innovation.

Read on LinkedIn
FAQ

Frequently asked questions

What is flinq?

flinq is the embedding API for the European construction industry. A cross-modal model maps heterogeneous construction data into one shared vector space, from bills of quantities and BIM models to site photos, manufacturer products, cost data and standards. These document types exist across Europe in different national formats; today flinq supports the German formats such as GAEB most deeply. Access is via an API.

Is flinq a SaaS product or an API?

flinq is an API service. The product is the model behind an API, not a finished application. Bill-of-quantities matching, cost prediction and RAG are examples of what you build on the API, not features flinq ships.

Which data and file formats does flinq support?

flinq reads common construction file formats and the domain content they carry. These are GAEB, IFC, PDF, JPG, PNG and CSV. From them the model recognises, among others, bills of quantities and tender texts, BIM models and building elements (including 3D geometry), site photos, manufacturer products, cost data and standards. GAEB here is the German format for bills of quantities, one national instance of a document type found across Europe, whereas IFC is an international BIM standard. Support is deepest today for the German formats. All are embedded into the same vector space.

How do I access the model?

Via an HTTP API. You send construction objects as a request and receive embedding vectors in return. The full reference and runnable examples live in the docs.

What can I build on flinq?

Typical examples are matching bill-of-quantities line items, early-phase cost prediction and RAG over construction data. Building on that, you can identify VOB-compliant tender texts or price bills of quantities via external cost databases. Further examples are pricing tendered line items via an internal cost database, matching manufacturer products to line items, classifying products by ETIM, and retrieving the relevant national standards, such as DIN. You build these applications on the API; flinq provides the embedding model, not the finished application.

What sets flinq apart from generic embedding models?

flinq is trained on domain-specific tasks. On the BauSatz benchmark, flinq small (0.6B) reaches nDCG 0.78 on product retrieval versus 0.60 for OpenAI, and recognises components by their 3D shape with 82.9% accuracy, while text-only models reach 6.3%.

Can I run flinq on-premise?

Yes. flinq is available as a cloud API and, on request, on-premise. Your data then stays in your environment.

Is flinq GDPR-compliant?

Yes. flinq is GDPR-compliant and hosted in the EU.

What is the quality of the embeddings based on?

On a curated, cross-modal dataset of matched construction objects. This dataset is the defensible core. The model backbone is swappable.

Build on flinq

Request API access or read the docs.

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