As an investor lender we see wide disparities in rehab. proposals from General Contractors. Rule number 1 is the contractor wants to get the job. Many contractors will under bid the job(Like a realtor over valuing a house, to get the listing) When the work begins hidden, or undefined work, results in a ballooning budget and disharmony between the investor and the contractor. I am suspicious of very low quotes. One of the ways to combat this is to get 4-5 proposals and never accept the lowest or the highest. There exist a myriad of good estimating software which will skew the pricing to your region. I always run my own estimate as a extra check on the reliability of the contractors proposals.
Often your low ball proposal is not specific as to scope of work. You discover that the contractor only intends to use a single coat of paint, or reuse materials which you wanted replaced. Repair not replace the roof. So detailed scope of work is essential. All of the proposals should be for the identical job. Do not add, or subtract work, from your proposal requests or you may be unable to compare one to the other. Do not forget to get an estimated time to completion. Time is money. Some of the lower priced contractors take on too much work. Your job drags on, causing you on your interest, or the time value of your money.
Every professional that you work with should bring some experience to the table in the real estate and construction fields. Your lender, broker, lawyer, banker or partner should all have sufficient experience in the real estate rehabbing and investment field, to help provide you the information you need to be successful. Good luck. Real estate is my passion.