This paper deals with a novel approach to study renewable energy options for buildings to make them more efficient more cost effective more environmentally benign and more technologically attractive To demonstrate the application of this study four buildings are chosen as case studies with two from the residential sector one commercial/institutional building and one industrial building A ground source heat pump for heating and cooling a solar water heater for space heating and/or hot water and a photovoltaic panel to generate electricity are designed for these case studies Attempt is made to design projects under hybrid systems combined from two technologies are developed for the above-mentioned four cases Results obtained indicate that solar thermal option for hot water and space heating becomes the most cost effective one for all cases (e g $4956 for Cases 1 and 2 and $70 652 for Case 3 and $91 361 for Case 4) In addition solar electricity through PVs is technologically the most suitable one to meet the electricity demand The ground source heat pump option is quite attractive from the efficiency and environmental impact point of views although it requires installation and maintenance etc Finally hybrid systems provide better advantages such as higher efficiency reduced cost reduced emissions etc (C) 2010 Elsevier B V All rights reserved