The neighbor communities are many who at some time raise to their lawyer the posiblidad to rent common zones with a view to generating income extraordinary. Communitarian parkings or roofs for the installation of solar panels are generally usable. What forecasts there are to observe to undertake this action? Essentially the necessary majority so that the adopted agreement is valid. We must observe Art. 17 of the Law of Horizontal Property, which arranges how the agreements in Proprietor Meeting must be adopted, and in whose point first it is asserted that for the validity in the agreements that imply the approval or modification of the rules contained in the constituent title of the horizontal property or in the statutes of the community the unamimity will be necessary, indicating itself in this same section of Art. 17, in the final interjection of the paragraph second of which " The renting of common elements that it does not have assigned a specific use in the building will also require the favorable vote of the three fifth parts of proprietors who, as well, represent the three fifth parts of the quotas of participation, as well as of the proprietors directly affected, if hubiere". This article that apparently can be contradictory even for lawyers, in fact is not it, since the jurisprudence is constant and pacific understanding that the true aim is to obtain special a qualified majority for the leasing of common elements; it without entering to value if such action can imply or not a modification of the constituent title or the statutes, something that in the majority of the cases ocurri.