Building a Home

Q: The house is only a 3 bed / 2 bath about 1380 sq. feet. I was wondering when it comes time to meet about having additions and so forth added on what are some good things to consider? So far I've asked to add HVAC setup, a covered backyard patio, and about 80 sq feet for like a bonus room/office. What are some things to consider that might add value and make living there better? Also I've asked for CAT6 cables to be run from the bedrooms and living room and to terminate in the office/extra room. Also our countertop is just laminate, I know it's the cheap but I just can't justify upgrading to quartz, then again I don't know much about homes/real-estate. Also are barn doors cool or just a waste of money?