GRAPPA, an imple­men­ta­tion of the Pal­la­di­an gram­mar, is intro­duced. Graphs are used for the under­ly­ing rep­re­sen­ta­tion, graph gram­mars take over the com­pu­ta­tion. Once a set of graph gram­mar rules equiv­a­lent to the orig­i­nal set of shape rules is defined, deriva­tions, in the form of attrib­uted graphs, are gen­er­at­ed. These graphs con­tain all nec­es­sary infor­ma­tion to out­put floor plans of Pal­la­di­an vil­las using an appro­pri­ate mapping.