Specifications include, but are not limited to: On an "as needed" basis. Contractors shall have the technical staff to perform diagnostic services; provide design services as needed; and to provide professionally prepared, stamped drawings, if needed, to obtain installation or construction permits. contractors may be capable of providing all new, upgrades or repairs to the existing mechanical service and systems, or completely new installations, diagnostic services, perform trouble shooting services for the Using Agency and to prepare proposals for all costs an services needed to perform the work required. The work may include all costs needed and required to remove and to repair any defective heating, ventilation and air conditioning (HVAC) systems, materials and related work;to provide all preparation work an lay-out needed and required for the repair of existing HVAC systems and installation of new work and systems: and any required maintenance and related work needed for existing HVAC systems. This may include any upgrades, replacements or new installations of equipment curbs, roof patching, concrete pads, screen walls, and associated ductwork.