A rather big wraparound ground floor extension was proposed here, doubling the area of the ground floor. Due to the pitched roof on the side, a cranked beam had to be utilized. Also, because of the long hip beams, the use of timber was not enough, so flitch beams were designed to optimize the use of timber and steel, getting a cost-effective solution for the issue. The extension floor was designed as suspended timber floor in accordance to the client’s needs. In order to open the space between the existing house and the proposed extension, the rear wall of the house was to be demolished. Steel box frame was utilized in order to support the external brick wall above, as well as to support the external ground floor side wall against lateral loads. Rendered external walls were proposed by the architect, hence the extension cavity walls were designed with internal & external blockwork.