Laundry. Guest Bath - really any bath. The only ones I'd think nah are closets but that doesn't add up to many doors so we just stuck with all solid core. I have read that some don't feel they really help with sound (I think they do but how much ???) but they just feel so much better.

Honestly I'd want solid core everywhere inside the house. They just "feel" better. Not flimsy.

I would only use solid core as well. I hate hollow core doors. In our last house, the hollow doors weren't even wood; they were a cross between Masonite and cardboard. I replaced them all. In our new house, I was lucky enough to score ten matching antique 5-panel doors for $10 each! They weigh a ton, and are very good at blocking sound.

We went with a combo of solid and hollow, using the solid doors for the master, master bath, guest bed and office. Hollow for every thing else. To go solid throughout would have been an extra $5.5k...

Around my area you need to be in the upper $850k before you regularly start finding houses using solid doors exclusively, if then.

I'm doing solid masonite.

I would do solid everywhere you can afford to do it. Our first house had gorgeous solid wood doors. This house has hollow core doors that are awful. It has been a huge difference and we plan to go back to solid wood when we build this summer.

Solid wood, (as opposed to solid core doors) are $109 at Home Depot, as an example. The labor to install shouldn't be any different.

I chose manufactured wood passage doors because I was going to paint them and the trim anyway. Our 3-foot-wide doors required four sets of hinges.

Solid core composite doors are what we typically install for all bathrooms, bedrooms, powder room, and any door that will be actuated frequently. If economy is an issue, hollow core doors can be used for closets. If the doors are 8 ft tall doors, we use only solid core doors; the hollow core versions just don't feel right.

We replaced all doors with solid core. Makes such a big difference.

Solid doors are so nice! You are all absolutely right, they feel better. I feel silly asking, but can I just replace a hollow core interior door with a solid one, or do I have to replace the whole jamb?

I've had two houses with hollow core doors, and in both we had issues with the hinge-mounted door stops on closet doors getting pushed through the door due to someone opening the door too far. We did solid core throughout in our new build, and it wasn't that much more expensive.

When I had the builder change them in my last house, he had to change the hinges, too because of the heaviness of the door. Same jambs, new hinges and doors.