Before founding his construction company, between 1967 and 1980 Tahsin Kaya carried out subcontracting work on 50,000 m² of residential and commercial buildings within the province of Istanbul. In 1980 he first set up a sole proprietorship, and in 1993 he founded Kayalar TK İnşaat Limited Şirketi to deliver the large projects he aimed for and to build a professional, corporate structure. Since its foundation, Kayalar TK İnşaat has never had a single problem with any public authority, bank, individual, landowner or private institution. It has completed all of its construction work in line with its contracts and the law.