Stability
You need to make sure that any contractor you do business with has proven themselves in the past, and will be there if you need them in the future. Don't just ASK the contractor if they are stable, look for tangible proof of longevity and financial stability by asking for these items:

Photos of Owner, Staff Members, Showrooms, Vehicles, etc.
Bank & Supplier Reference Letter
Proof of Insurance
Business License

Reputation
One way to judge a home improvement company is to find out what others who deal with them have to say. A good reputation isn't built overnight--it is earned through years of rendering good service, treating people right, doing what you say you'll do, going the extra mile, and respecting customers. Ask for the following items to see how you can accurately judge the reputation of any contractor.

Chamber of Commerce & Other Memberships
Customer Reference List
Accolades

Professionalism
A good home improvement company doesn't just do good work. They also understand that when dealing with customers, it's oftentimes the little things that make a big difference. You should find a contractor that shows you respect by the way they treat you, the way they look, the way they treat your property, and how they pay attention to details. Check any contractor you're considering using against these standards of professionalism:

Worker Conduct Agreement
Bid Specifications
No Sales Pressure Agreement
Jobsite Cleanup Standards

Workmanship
Ultimately, any contractor has to be competent to do the job right the first time. Competence comes as a result of training, experience, and good old fashioned hard work. As you evaluate a contractor, look for signs that they can do the job right the first time.

100% Satisfaction Guarantee
No-Nonsense Lifetime Warranty
No-Nonsense Glass Breakage Warranty

Contractor Frequently Asked Questions