QSi is the only professional body which solely caters for Quantity Surveyors. QSi is a non-profit-making professional body for those specialising in the financial aspects of construction and engineering. 

The objectives of QSi are:

• To support and protect the character, status and interests of the profession of Quantity Surveying.
• To promote good practice and high standards from its members.
• To consider all questions affecting the interests of the profession and to petition Parliament to promote legislation affecting Quantity Surveyors or their profession.
• To disseminate to members information of a technical and contractual nature which relates to their work.
• To publicise throughout the construction industry the benefits which can be derived from the employment of Quantity Surveyors.
• To promote the employment of Quantity Surveying skills in helping to make the construction industry more efficient.
• The provision of recruitment, training and lifelong learning facilities.