Global warming is one of the biggest challenges today, and the construction sector is one of the main sectors contributing to climate change. Due to this, using environmentally friendly materials in construction is an important decision against global warming. This thesis aims to evaluate the most important building envelope components to achieve a house in Sweden to become near net-zero energy building (ZEB). Due to this, different ecological insulation materials, and window types were presented, analyzed, and evaluated to choose the most energy-efficient alternatives for the Utsikten village project. In terms of reduction of electricity bought, renewable energy on-site photovoltaic (PV) and ground source heat pump systems are used. In this study, numerical simulations for building envelope components such as windows, ground floor, external walls, and roofs were performed to evaluate the thermal performance of the components by IDA ICE and UBAKUS. The primary energy for different building cases has been calculated to evaluate thermal performance and energy classification levels to identify the most environmentally friendly solutions. There is a variation of ecological material for insulation that can be used for different parts of the building envelope. In general, ecological insulation material has less life expectancy but a much lower environmental impact compared to minerals and synthetic materials. However, there are also some limitations to using some ecological insulation materials in the ground construction. This study also shows how several pane glasses, gap dimensions, gas fill gap, and Low-E coating impact the energy performance of the windows and the building. Simple solar PV panel simulation shows that the maximum electricity production on a site is very related to orientation, tilt, and sun exposure. The result of this master thesis shows that it is possible to reach near-net-zero energy building by enhancing building envelope components and using renewable energy sources for heating, cooling, and electricity production.