It will be necessary to calculate the volume of the foundation because it will be subject to various loads. After laying the foundation, you can take on the construction of the frame of the future building. For this, a set of fasteners for the undergrowth and rafter system is suitable, a verandal beam 5-10 cm thick is suitable as a rack and rafters. At the end of the assembly of the frame, you can start the installation of windows and doors, and then start the skin of the walls. The roof should be made single -shield with a slope from the house. The entire wood should be treated with a septic tank, the cracks are blown with mounting foam. Observing the technology and the sequence of work will be, the result you need, and the veranda will last many years.