This document outlines an approach to developing a soft tool for conducting a life cycle assessment of residential buildings to estimate their environmental impacts, such as carbon emissions. The tool calculates embodied carbon emissions from building materials used in construction and from electricity consumption over the building's 50-year lifespan. Testing on a residential building in Pune, India found total embodied carbon from materials was 748579 kg and from electricity was 4266150 kg over 50 years. The results indicate opportunities to reduce impacts by using sustainable materials and non-conventional energy sources.