Are they familiar with similar projects
Each Northern Virginia home improvement contractor may have more experience and knowledge in particular improvement type such as kitchen improvement, bathroom improvement, roofing, flooring, carpeting, decking etc. In the selection process check portfolios of the contractors to know whether they already have successfully done the projects that are similar to yours. If your home improvement project includes many tasks home improvement contractor may hire sub-contractors who are specialized in those remodeling types. For an example if a remodeling contractor is not familiar with constructing a deck that you wanted to have behind the home, he may hire a sub-contractor who is specialized in decking to do the job. Bottom line is try to hire a contractor with experience in many types of remodeling projects or at least make sure the main contractor has referrals to professional sub-contractors.
Status of previous jobs the contractor has done
If a remodeling contractor is confident on their prior jobs, he should let you know without hesitating for whom he has done the projects in the past. If possible try to contact past clients of the remodeling contractor and check with the current status of the their remodeled home. For an example whether the work had done by the contractor is still in good conditions or not. If the remodeling contractor have done a good job, you will receive recommendations from his past clients.
Liability towards quality work and safety
Home improvement contractor should guarantee their work with some kind of a warranty such as what steps they will take if something goes wrong during the project or after the project is finished, also the safety of the home residents, neighbors and workers. Do not forget to come to an agreement on these facts before initializing the project. Otherwise if some damage occurs to neighborhood property due to a fault of your home remodeling contractor you may have to take up the responsibility of it. If you are not familiar with the legal stuff you may ask for help from Northern Virginia authorities.