Choosing a contractor to build an extension can be a daunting task. The best way to start is by getting a few quotes from local contractors that specialize in your area. You can find these contractors by searching online or asking friends and family for recommendations.
Once you've found some contractors, it's important to do your research! Look at the companies' websites, read reviews on other sites like Yelp or google reviews, and ask about their experience in doing projects similar to yours. If you're hiring a general contractor, ask about their insurance coverage and safety certifications.
When meeting with potential contractors, make sure they're willing to answer all of your questions—and ask as many as possible! It's also important that they have references from previous clients so you can speak with them directly about their experience working with this contractor before signing any contracts yourself.