## 2 Workflow
Rhinoceros(tm) and Grasshopper(tm) have been used for this architectural modelling stage; the computational environment of Grasshopper(tm) has allowed to speed-up form generation, with a group of forms that could be easily (re)generated thanks to its parametric modelling capability. A diagrid pattern representing the outer structure of each building is then mapped on its skin. The diagrid is assumed to have a tubular cross section and pinned joints. The concrete slabs at each floor are assumed as a rigid diaphragm transferring the dead load to the core, while the diagrid structure has to sustain the lateral loads representing the seismic effects according to the statically equivalent method. The dead load is assumed to be constant and equal to 4.50 kN/m\({}^{2}\), while a 2.50 kN/m\({}^{2}\) live load is considered; all floors receive 100% of the dead load and 20% of the live load. Since our objective is to ascertain the feasibility of the ML approach to link architectural and structural choices, we make here the conventional assumption to allow for a weak seismic event, which implies that a linear elastic response of the structure is taken into account. The response is therefore purposely assumed to be not significantly affected by modes of vibrations higher than the fundamental one in each principal direction. The total amount of the equivalent lateral force is computed according to Eurocode 8 and then applied at the center of mass of each story proportionally to the floor height and mass [34]. Seismic and other loads are combined with their deterministic value, i.e., in the load combination a factor of 1 is simply assumed. More precisely, the seismic force is computed by following this procedure: (i) the input acceleration is determined according to the design spectrum; (ii) the base shear force is computed; (iii) the said shear force is distributed among all stories. The design spectrum \(S_{d}\) is set by the standard and it can be computed on the basis of: the design ground acceleration \(a_{g}\); the soil factor \(S\); the behavior factor \(q\); the fundamental vibration period \(T_{1}\) along the direction of interest; the periods \(T_{B}\), \(T_{C}\) and \(T_{D}\), related to the start of the acceleration-constant branch, the start of the velocity-constant branch and the start of the displacement-constant branch in the design spectrum, respectively. As indicated in [34], the expression to be used in case of a low seismic event characterized by \(T>T_{D}\), is:  
\[S_{d}(T_{1})= \begin{cases}a_{g}\,S\,\dfrac{2.5}{q}\left(\dfrac{T_{C}\,T_{D}}{T _{1}^{2}}\right)\\ \geq\beta\,a_{g}\end{cases}  \tag{1}\]  
with the values specified in Table 1 for the ground located in Tehran, Iran (ground type C). Figure 1: Generation of the 144 architectural models for the tall buildings considered in this work. (**a**): perspective. (**b**): plan view to get details of top and bottom floor plans, and direction of the applied seismic load. It is worth stressing that the linear static assumption is somehow enforced: in view of our objective (ML-based classification), the seismic load should be therefore considered as a conventional horizontal excitation to compare different design alternatives, more than an actual representation of the earthquake action. The encouraging results for the classification that are going to be shown in Section 4 will spur us to pursue improvements in the future as to the representation of the actual seismic load and response. The fundamental vibration period for all the models included in this research has been computed using Karamba(tm), a structural analysis plug-in for Grasshopper(tm) [35]. In addition, the adopted standard defines a lower bound for \(S_{d}\), represented by the product of the lower bound factor of the horizontal design spectrum \(\beta\) and \(a_{g}\): it is worthwhile to mention that in most cases this second alternative, shown in Equation (1), is used.