Presuming it is 2 story with ladder work involved, I would suggest that price is low. Depending on how many guys you have and how long it will take to complete may be a factor as well. May I also suggest that you consider how long you have to wait for your payment. In my life and business experience the bigger the company the longer they take to pay. Looks like you may have a good relationship with the builder that’s always a plus.
Take into account the surrounding areas of the jobsite. Will there be other people working in and around you while you perform your service. They will cause you to take extra steps and will slow you down and move you off your target per hour range. Might not hurt to post a pic of said job you are bidding on so folks can see the scope of work and better aid is advisement. Best of Luck Elements