What is a solid core door, and is it worth the extra cost?

A solid core door replaces the hollow honeycomb cavity with a dense engineered core, so it weighs far more, blocks noticeably more sound, resists dents and closes with a substantial feel. For bedrooms, bathrooms and home offices the upgrade usually pays back in comfort and resale appeal. For closets, pantries and low-traffic storage, a hollow core remains a sensible saving.