First of all, the referrals are usually the starting point. You should consult the phone book in order to get the contact numbers and addresses of the potential contractors.
Consult with your friends or family members who already have metal buildings. Seek for their help which will give you a better idea in choosing a contractor.
Also discuss the details of your metal building with your friends or family members and get an idea of what you should demand from the contractor before finalising the deal.
Try to get bid from different contractors for the construction of your metal building and choose the one who you think is the most suitable for the job.
Make sure that the bid is less than your anticipated budget as sometimes you have to make amendments that also increase the expenses.
Do not forget to ask all expenses to the contractor in order to take a better idea and go ahead if you have enough money to complete the project after having a conversation with the contractor.
Make sure that your contractor uses the best material as many contractors cheat their clients by using low quality material.
You should also compel your contractor to complete the project in minimum possible time without compromising on the quality of the metal building.
The most important thing before finalising the deal is that make sure your contractor has an insurance policy which is a warranty for you that you will not have to bear the loss in any case whatsoever.