1. Develop a cost estimate for all of the renovations. Try to get real bids from real contractors and search for actual costs for materials, such as appliances, cabinets, etc. Include photos of potential items as well. Be sure to list all of your major assumptions, and document your results in a spreadsheet format. Make it easy to change inputs, such as cost per foot of flooring, number of windows, cost for appliances, the furnace, etc.