Helse Bergen HF would like to enter into a framework agreement with a certified construction company for installation and maintenance work on water and sewage outside houses at the institutions of the health company within the discipline water and sewage. Helse Bergen HF would like tenders for framework agreements on hourly rates and materials connected to installation and maintenance work. The framework agreement is intended to cover the Contracting Authority's continual need for services in the discipline. The work assignments can be for a short or long period.  It can be an individual job or several saman-hanging jobs. Helse Bergen HF has a greater need for this service within ordinary working hours on ordinary working days.  Outside ordinary working hours, Helse Bergen HF has an occasional rare need for this service.