How Much Does BTO Interior Design Really Cost in Singapore? The cost of BTO interior design in Singapore typically goes from $30,000 to $80,000, depending on the flat size, design style and choice of materials. Basic 4-room BTO renovation costs from S$35,000, while a fully customised design with quality finishes can go upwards of S$60,000. Cost can depend heavily on the scope of the carpentry work, false ceilings, the type of flooring you choose and whether you hire a full-service interior design firm or a renovation contractor.  Read more: https://www.bulbapp.com/u/-~i6a5ef49bc70af94191eb6139