The average price for an interior design and renovation package is around $1,000/sq.ft, with a price range of $800-$1,200/sq.ft. The full house renovation package includes interior design as well as all design fees, design drawings, and construction drawings. If the designer only provides design drawings, the cost of pure interior design is about 30% cheaper. The cost of interior design depends on the unit area, spacing, designer qualifications and experience, design style, and material requirements. For example, for a practical area of 400 sq.ft with 2 bedrooms and 1 bathroom, the cost of pure interior design drawings ranges from $20,000 to $100,000. The larger the area and the more complex the renovation project, the higher the interior design price will be.