A Quantity Surveyor (QS) is a construction industry professional with expert knowledge on construction costs and contracts. Qualified professional quantity surveyors are known as Chartered Surveyors (Members and Fellows of RICS) in the UK and Certified Quantity Surveyors (a designation of AIQS) in Australia and other countries. In some countries such as Canada, South Africa, Kenya and Mauritius, qualified quantity surveyors are known as Professional Quantity Surveyors, a title protected by law.