Abstract The approach of using ‘magnetic bricks’ to build up different sorts of networks via supramolecular interactions is discussed. Two sorts of magnetic brick, with 3 and 12 linked Cu(II) centres, respectively, are used to illustrate this idea. The trinuclear brick has been crystallographically characterised in three compounds and can be used to create pseudo-Kagome networks. Magnetic measurements are reported on two of these compounds. The dodecanuclear brick has been crystallographically characterised both as an isolated aggregate and as units linked together in one, two or 3D arrays. Magnetic data are described for three of these compounds.