This project aims to characterize the strength capacity and stiffness of four unique integral mechanical attachment joints in monotonic tensile loading. The four joints were specially designed and fabricated using CNC fabrication techniques for their deigned use in modular house construction. The strength and stiffness characteristic testing of the joints was done to reduce the flexibility and uplift of a shear wall in the Wikihouse skylark 250. Where the shear walls are composed of hollow structural beam and column element members, which are connected with integral mechanical attachment joints. The joints were identified as the limiting building structural element in the rigidity of the system. The current connection joints have not been thoroughly investigated or optimized. The project took a four-stage approach to model, fabricate, test, and analyse the integral mechanical attachments designed as the solution to increase rigidity. The results prove that two new designs can improve the stiffness of the structure. The strength improvement of 38% and 41% was identified, however only one joint, the triple bowtie, has a greater stiffness capability at an 48% increase.