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Reciprocal systems based on superimposition joints, i.e. where un-notched bars sits on the top or in the bottom of each other, could be regarded as being intrinsically three-dimensional because of their natural out-of plane development. This paper presents seven of these three-dimensional configurations, conceived and built by the students of the Master of Science in ''Architectural Design'' at Aalborg University. They have been developed as an integral part of a 2-week workshop, organized and run by the authors during the fall semester 2011. Since physical models are instruments that trigger the exploration of new typologies because of the direct interaction they provide with the designer the students were called to deal with the issue of three-dimensionality in reciprocal systems through scale models and actual scale prototypes.

Timber gridshell structures, such as the Multihalle for the federal garden festival in Mannheim or the Downland Museum, have been the result of a creativegenerative process that indissolubly 'welded' the structural contribution to that of form exploration. The challenging design and construction issues have typically been addressed and resolved in several inventive but tedious steps and still till now, form-finding and erection of timber gridshells present difficulties that require radical solutions. In this regard, this paper aims to provide a series of novel steps to address some of the main design and construction issues that are associated with 'actively-bent' timber gridshell structures. First, the main characteristics of the construction process of timber gridshells are described and the basic theoretical concepts for its numerical simulation, through Dynamic Relaxation method, are introduced. Second, a practical method for sizing the laths' cross-section is presented. Third, a new erection technique for timber gridshells is proposed and applied to the construction of a full scale (prototype) structure, the Toledo gridshell 2.0. Fourth, a new bracing system for the same structure, which was built at the Faculty of Architecture, University of Naples Federico II in June-July 2014, is explained and discussed. The paper also highlights the need for further application to validate the techniques explained here, with particular attention being paid for the construction of large scale free-form structures.

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This paper presents an optimization procedure for the solution of the planarity problem, a requirement of grid shells with four or more sides faces that need of having four adjacent nodes laying on a plane in order to use plane glass slabs as cladding elements. It can be satisfied by applying specific geometric rules in the grid generation phase but, when the architectural shape is already defined at the conceptual stage, an optimization procedure can yield to suitable configurations. A Relaxation method based on nodal planarity errors and an evolutionary population based Genetic Algorithm have been applied to set of benchmarks, in order to tune parameters and to obtain general information about the solution. the problem and their efficiency compared. The Relaxation method in general shows better efficiency in reaching optimal solutions, as an effect of the regularity of the target function. The Genetic Algorithm, on the other hand, performs a wider exploration of feasible solutions, generating unexpected sub-optimal configurations.