I. – The tax is established on the basis of the net income serving as the basis for the property tax, defined by Article 1388.
The tax base for dwellings occupied by civil servants and civilian or military employees referred to in article 1523 is equal to their rental value determined under the conditions provided for in article 1494 and reduced by 50%.
II. – The communes and their public establishments for inter-communal cooperation as well as the mixed syndicates may decide, by a deliberation taken under the conditions provided for in 1 of II of Article 1639 A bis, to cap the rental values of each residential premises and each of their outbuildings within the limit of an amount that may not be less than twice the amount of the communal average rental value of residential premises.
The average rental value is determined each year by dividing the total rental values of residential premises in the municipality, excluding exceptional premises, by the number of corresponding premises; it is increased each year in proportion to the change in the rental values of housing resulting from the application of articles 1518 and 1518 bis.
This ceiling, reduced by 50%, applies to the net income defined in article 1388.
III. – By way of derogation from II of this article, when a public inter-municipal cooperation body with its own tax system makes use of the cap, the average rental value of residential premises may be calculated at the level of the public inter-municipal cooperation body or the union. It is determined by dividing the total residential rental values of the municipalities that are members of the public inter-municipal cooperation body with its own tax status or of the syndicate, excluding exceptional premises, by the number of corresponding premises.