Holzbau Janssen GmbH is a German company serving the German market, operating under Holzbau Janssen GmbH and active since 1994. The business is positioned around timber-frame construction, prefabricated wooden elements and custom house projects.

Its services are centred on carpentry, prefabricated timber elements, roof and wall construction, house extensions and full timber-building projects. It is relevant for clients planning offices, education, accommodation or other non-residential buildings with a prefab approach.