When we bought our current home (125 year old farmhouse in serious need of repair) I walked in the door and it immediately reminded me of my Grandma's house, and felt like "home" from the start.
When we remodeled the entry way, we found a lot of mold and rot in that area. No wonder it reminded me of Grandma's house. We'd go in the back door and you could either walk down the steps into the basement or up a few steps and through the door to the house. So the smell that was always first to hit you walking into Granny's house was musty old basement. The rest of her house usually smelled like what ever she was baking at the time.