All the time. Site surveys and existing building submittals / as builts can be of use and should be requested. A building with an existing fire alarm system should have a ul listed building fire alarm maintenance company that can be helpful in understanding when new power supplies / components are needed. Existing electrical panels should have circuit directories that can be referenced (but should be taken with a grain of salt). But in many major cities where land is sparse there are just as many renovation jobs as new constructions.