142. However, the assessment of the sales value of the plot of land is a bit less obvious to corroborate; the reason being that the Complainant does not provide any official source or basis for determining the coefficient of 2.5% applied in this case. The Commission notes in this regard that the relevant practice requires that the Complainant should have conducted an expert assessment, the report of which should indicate the reliability and validity of the coefficient applied. In the absence of such evidence and in order to expedite the procedure, the Commission is of the view that the issue has to be referred to the competent administrative and judicial authorities of the Respondent State for them to determine the coefficient to be applied to the cost price mentioned above in order to arrive at the sales value of the plot of land. The assessment shall be made on the basis of the national or international standards applicable in the territory of the Respondent State. 143. In any event, and since the plot of land has been declared as reserved for the housing of the Complainant’s family, the sales value shall in no case be lower than that of a plot of land of equal size, situated in an area of equal standing and offering the same facilities. Such an assessment will only be fair given that it is an empty land, and the development costs have been included when calculating the material damage to be considered below. 144. Without prejudice to such a conclusion, the Commission is of the view that the importance of the right to property and the right to adequate housing in the context of Africa requires that the fate of a Complainant who is a victim of de facto expropriation should not depend exclusively on the vicissitudes relating to the internal procedures of the Respondent State responsible for the established violation. Under such circumstances, it is necessary to provide for a procedural guarantee which protects the Complainant from any uncertainty regarding the enjoyment of prompt and effective reparation. 145. In this regard, the Commission is of the view that on the basis of the customary nature of the right to property whose guarantee by the African Charter has been firmly established, the implementation of a decision issued pursuant to the African Charter is mandatory.46 The Commission’s position on this issue is stated in its Resolution 97 on the importance of the implementation of its recommendations under which a Respondent State is required to implement within a period of six months. This Resolution derives its legal basis from Article 45(2) of the African Charter, and its validity has been endorsed by African Union policy organs, in particular through See F. Viljoen International Human Rights Law in Africa (2012) pp. 355-356; K. Bonneau ‘Le droit à réparation des victimes de violations des droits de l’homme : le rôle pionnier de la Cour interaméricaine des droits de l’homme’ (2006) 6 Droits fondamentaux. 46 34