Does anyone know of an existing knowledge graph for houses/buildings?

SWJ had a special issue in 2018 on Semantic Web for the Built Environment. See http://www.semantic-web-journal.net/issues (scroll to 2018). There may be pointers in those papers.

Or are you thinking more GIS style?

Thank you! I'm interested in evaluating both options, but will start with the SWJ issue you linked.

LDAC is a pretty good place to start... LDAC2020 - Linked Data in Architecture and Construction http://www.linkedbuildingdata.net/ldac/index.html

Cf. linked data work on BIM Linked Data for buildings - Technology Cards https://www.technologycards.net/the-technologies/linked-data-for-buildings (PDF) Building Knowledge Extraction from BIM/IFC Data for Analysis in Graph Databases https://www.researchgate.net/publication/325078444_Building_Knowledge_Extraction_from_BIMIFC_Data_for_Analysis_in_Graph_Databases isprs-annals-VI-4-W1-2020-93-2020.pdf https://www.isprs-ann-photogramm-remote-sens-spatial-inf-sci.net/VI-4-W1-2020/93/2020/isprs-annals-VI-4-W1-2020-93-2020.pdf swj1582.pdf https://www.semantic-web-journal.net/system/files/swj1582.pdf

If real estate is interesting to you you may look at what Cherre is doing, cc Ron B.

I've been looking into RealEstateCore for our needs, and here are some links: https://doc.realestatecore.io/3.3/full.html https://github.com/Azure/opendigitaltwins-building

Wow, thanks to all for responding!

also the brick schema