Which statutes (BauGB, BauNVO) are included?

The BauGB, BauNVO, HOAI and ROG, each provision available on its own. The building codes of the federal states are state law and not included.

Are the administrative courts of the federal states included?

Yes, as far as the states publish their decisions. 13,000+ decisions in this area come from administrative and higher administrative courts. The "Courts" table lists the count per court.

What does access cost?

Every call uses credits from your organization's balance, the same one the web app uses. A search costs 1 credit. The table above lists the price per tool. Your first organization receives 30 credits once, valid for 30 days.

How do I connect Claude, ChatGPT or Cursor?

Add the MCP address on this page as a custom connector. Claude and ChatGPT sign in with OAuth. Cursor and your own agents use an API token. The MCP documentation lists the steps for each client.

Are the case numbers in the answers real?

Every case number Klaracase returns points to a decision in the corpus, with court and date. You can fetch and read the full text at any time. The legal assessment stays with you.

API and MCP

German building law: court decisions and statutes via API and MCP

The case law on public building law, ready for your software and your AI assistant. Development plans, outer zones and neighbour protection, each with case number and the norms it cites.

Decisions from 1978 to 2026.

https://klaracase.de/mcp/baurecht

Built and operated in Germany

Server location: GermanyOne dedicated server hosted by Hetzner in Germany. Backups are stored encrypted in Frankfurt (eu-central-1).

Recipients disclosedEvery service that receives data from you is named in the privacy policy, with its purpose and location.

Built in GermanyBuilt for German law: court decisions, statutes and citations from German sources.

Data processing. The AI services that receive your search query process it in the EU. The providers belong to companies based in the USA. More on privacy and security

In the corpus

Decisions: 16,000+
Courts: 20
Statutes: 4
Linked citations: 87,000+

Decisions from 10 May 1978 to 28 July 2026. Measured on 11 October 2026.

Example query

One question, one call, real case numbers

A recorded query from 11 October 2026. Every case number below exists in the corpus, and the excerpts are verbatim.

Question

When is a building project in the outer area permitted under section 35 BauGB?

Call

search_decisions({
  "query": "Wann ist ein Vorhaben im Außenbereich nach § 35 BauGB zulässig?",
  "cited_statutes": [
    "BauGB",
    "BauNVO"
  ]
})

Answer

5 K 769/11 · Verwaltungsgericht des Saarlandes 5. Kammer · 27 February 2013
Grundlage des § 35 Abs. 1 Nr. 1 BauGB ein Genehmigungsanspruch zur Seite steht, weil sie einen landwirtschaftlichen Nebenerwerbsbetrieb beabsichtigen. Nach dieser Vorschrift ist ein Vorhaben …
2 A 247/21 HAL · VG Halle (Saale) 2. Kammer · 22 April 2024
belegenen Grundstück errichtete Gebäude ist auch kein im Außenbereich privilegiertes Vorgaben im Sinne des § 35 Abs. 1 Nr. 2 BauGB. Danach ist ein Vorhaben …
4 K 1016/12.NW · VG Neustadt (Weinstraße) 4. Kammer · 18 April 2013
Nutzung ist nach - dem hier allein in Betracht kommenden - § 35 Abs. 1 Nr. 4 BauGB jedoch nicht genehmigungsfähig. Danach ist ein Vorhaben im Außenbereich nur …

Use cases

Three ways to use Construction law

Projects in the outer zone

Find decisions on § 35 BauGB and narrow them by higher administrative court and period.

Judicial review of plans

Your agent reads judgments on invalid development plans in full text and follows the citations to earlier decisions.

Type of land use

Read the zoning rules of the BauNVO and the decisions on them in a single call.

Connect

Connect to Construction law in a few minutes

This address searches the Construction law area only. Claude.ai and ChatGPT sign in with your account. The other routes use a token.

Claude Code: run the command in a terminal and replace YOUR_TOKEN_HERE with your token.

claude mcp add --transport http klaracase-baurecht https://klaracase.de/mcp/baurecht \
  --header "Authorization: Bearer YOUR_TOKEN_HERE"

Claude.ai: add a custom connector and enter this address. You sign in with your account.

https://klaracase.de/mcp/baurecht

More in the documentation: MCP documentation, REST API documentation

Coverage

What Construction law covers

Decisions by court

Court	Decisions
OVG	7,800+
VG	5,100+
BVerwG	2,400+
OLG	240+
BGH	230+
FG	170+
LG	100+
BFH	52
BVerfG	51
LVerfG	38
LSG	11
BSG	8
OTHER	8
AG	8
LAG	7
SG	5
BAG	3
BayObLG	3
BPatG	1
ArbG	1

Most cited norms

Norm	Citing decisions
§ 34 BauGB	5,300+
§ 35 BauGB	4,200+
§ 1 BauGB	4,000+
§ 9 BauGB	2,000+
§ 15 BauNVO	1,900+
§ 214 BauGB	1,800+
§ 31 BauGB	1,800+
§ 30 BauGB	1,700+
§ 2 BauGB	1,600+
§ 4 BauNVO	1,300+

Most cited decisions

Case number	Court	Date	Cited by
4 VR 5/14	BVerwG	25 February 2015	610+
4 A 1075.04	BVerwG	16 March 2006	490+
9 CN 1.01	BVerwG	17 April 2002	410+
4 C 15.01	BVerwG	17 December 2002	320+
4 CN 1.07	BVerwG	9 April 2008	320+
4 C 8/11	BVerwG	29 November 2012	300+
4 C 5/12	BVerwG	5 December 2013	280+
1 BvL 10/02	BVerfG	7 November 2006	270+

Statutes in this area

BauGB Baugesetzbuch
BauNVO Verordnung über die bauliche Nutzung der Grundstücke
HOAI Verordnung über die Honorare für Architekten- und Ingenieurleistungen
ROG Raumordnungsgesetz

Cost

What a call costs

Every call costs a fixed number of credits. New accounts get 30 credits once, valid for 30 days.

Tool	Purpose	Credits
search_decisions	Search decisions	1
get_decision	Full text of one decision	1
get_norm	Current text of one norm	1
get_citation_graph	Citations of one decision	2
assemble_datapackage	Data package from several decisions	5
list_facets	List filter values	free

See pricing and plans

Questions

Frequently asked questions

More areas of law

Back to the overview of API and MCP

Start with Construction law

Data processing. The API and the MCP server use the same search as the web app. OpenRouter and Voyage AI process the text of a search query in the EU. Citation Check examines texts on our server in Germany, without AI services. More on privacy and security