Tersus Building Services Inc. is first and foremost, a proactive company dedicated to meeting the needs of its clients. With more than 35 years of experience in the facility services industry. Environmental concerns and new technologies have taken commercial cleaning services to a new level.Servicing Montreal and surrounding areas, Tersus Building Services combines today’s technology with more than 35 years of innovative experience. That means we can offer you a full range of solutions based on your individual needs.