Remodeling an existing building typically costs less than new construction or adding an addition. However, it's crucial to ensure the structure can bear the weight of any new modifications. In this area, remodeling costs range from $100 to $200 per square foot. Kitchens and bathrooms tend to be pricier than bedrooms, with costs escalating based on the luxury of the finishes. If you're aiming for a high-end or custom remodel, expect costs to climb to $300+ per square foot.