Rectangulations include packings of rectangles in two dimensions and p
ackings of cuboids (3-rectangles) in three dimensions. Spatial layouts
of this type are used in architectural and engineering design. In thi
s paper we examine the spatial relations between the lines, planes, an
d volume elements in these designs. It is shown how to describe rectan
gulations as shapes in product algebras. Spatial relations, particular
ly adjacencies between areas, volumes, maximal planes, or maximal line
s are used to represent rectangulations. More general properties of th
ese spatial relations are derived. Generative properties of rectangula
tions are established which distinguish those 3-rectangulations which
have an essentially two-dimensional character.