Isabel,

Alıntı: Doesn't the individual have any ownership rights - human rights?

Article 35 of the Turkish Constitiution :" Everyone has the right to own and inherit property.These rights may be limited by law only in view of public interest.
The exercise of the right to own property shall not be in contravention of the public interest."

Article 12 : Everyone possesses inherent fundamental rights and freedoms which are inviolable and inalienable.

Article 16 : The fundamental rights and freedoms of aliens may be restricted by law in a manner consistent with international law.

Alıntı: I didn't know that such dictatorship existed in Turkey

Your concerns as regards the legality of the Art. 18. are considerable. Notably, Article 18 confers the state authorities a comprehensive power regarding zone development and planning. One may call this application, in a sense, as a gratutious expropriation of private property. However, Turkish Constitutional Court dismissed the claim of unconstitutionality of Art. 18 in a decision on these grounds: "Article 18 of the Zone Development Act envisages not a cessation but a fair limitation of private property in line with the public interest.Additionaly, the restriction applied is compensated by the valuable improvements of the property."

European Convention On Human Rights stipulates that " No one shall be deprived of his possessions except in the
public interest and subject to the conditions provided for by law and bythe general principles of international law."

As you can see, the enjoyment of a fundamental right may be restricted upon "general interest" and several specific grounds, not only in Turkish but also in the international law. Turkey is not a "dictatorship" but a country ruled by a secular and democratic law. You may seek judicial observation of legality of official acts in Courts(Courts of Administration). You may also recourse to the European Court Of Human Rights in case you are not pleased with the judgement rendered in Turkey, in the six months after the last domestic remedy here is exhausted.