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HomeMy WebLinkAbout02/27/1996, 2 - CITY HALL SEISMIC SAFETY AND HVAC IMPROVEMENTS PROJECT SPECIFICATION NO. 9101-540-553 �Il�l�ul�llllln„I nl� MEET GDA II l c� of san tins oBispo N� �: COUNCIL AGENDA REPORT FROM: Michael D. McCluskey, Public Works DireoW Prepared by: David Elliott, Administrative Analys� SUBJECT: City Hall Seismic Safety and HVAC Improvements Project Specification No. 9101-540-553 CAO RECONIlbfEMATIONS 1) Approve plans and specifications for "City Hall Seismic Safety and HVAC Improvements Project - Specification No. 9101-540-553” 2) Authorize Public Works to advertise for bids 3) Authorize the City Administrative Officer to award the construction contract if the successful bid is less than $1,276,200 4) Appropriate an additional $476,200 from bond proceeds to the project account REPORT-IN-BRIEF Plans and specifications for the City Hall Seismic Safety and HVAC Improvements Project are completed and ready to advertise for bids on a construction contract. Additional unforeseen costs for construction and construction management have increased the overall project cost estimate from $1,020,000 to $1,496,200. Additional construction costs include fire sprinkler installation ($56,100), additional asbestos removal ($98,400), emergency generator replacement ($49,600), custom HVAC equipment ($15,000), and Americans with Disabilities Act (ADA) accessibility improvements ($27,600). Additional construction management costs include contract resident inspection ($65,600) and contract materials testing and inspection ($9,400). The increased project budget will require an additional $476,200 appropriation from bond proceeds. DISCUSSION Project Scope The project engineer for the City Hall Seismic Safety and HVAC Improvements Project has completed plans and specifications. Public Works has submitted these construction documents for building permit planchecking, and the first review was completed on February 13, 1996. Final review and approval will be completed before advertising for bids. This project has two major components: 1) correcting structural deficiencies to help the building withstand a major earthquake and 2) repairing and improving the heating, ventilating, and cooling (HVAC) systems. The attached 1995/97 Financial Plan project request fully describes this project and these two components. The existing project budget was prepared after schematic design was completed and before construction document preparation started. The project budget will require another $476,200 appropriation from bond proceeds to cover additional unforeseeable costs for construction and construction management. ������i ►�IIII���►° 9���U city of San tins OBISpo COUNCIL AGENDA REPORT Additional Construction Costs The existing project budget for construction is $875,000, and the estimated cost for construction is now $1,276,200. Most of the $401,200 difference is the extra cost of five significant components added to the project during construction document preparation: fire sprinkler installation, additional asbestos removal, emergency generator replacement, custom HVAC equipment, and ADA accessibility improvements. Fire Sprinkler Installation. Currently only the lower floor areas have fire sprinklers. Because of a more restrictive building-type determination by building and safety division, the project engineer had to specify either installing fire sprinklers in the attic or spraying a fireproof coating over all structural steel members. Fire sprinklers were the cheaper alternative, and it made sense then to install sprinklers for the upper floor areas using the same distribution system, because the Municipal Code requires fire sprinklers throughout City Hall by the year 2000. Additional Cost: $56,100 Additional Asbestos Removal. To make room for HVAC equipment and ductwork, the construction contractor will have to remove batt-type insulation from the attic and pipe insulation from the area above the lower floor ceiling. Both types of insulation contain asbestos, which requires special handling and additional expense during removal. This expense is in addition to the cost of removing the cementitious roof panels, which also contain asbestos. Additional Cost: $98,400 Emergency Generator Replacement. The existing emergency generator was second-hand when it was installed in the early 1980's and has marginal capacity for its intended use. Because the electrical service will be improved to accommodate the HVAC equipment, it makes sense to replace the emergency generator at the same time. This replacement is an additive bid alternate which will be incorporated into the construction contract only if the budget will accommodate it. Additional Cost: $49,600 Custom HVAC Equipment. The existing boiler room will accommodate the new boiler and one of the two specified air handlers. The cooling chiller and second air handler must be located in the mechanical well on the roof, because there is no room inside the building and locating this equipment on the ground outside would be unsightly. To lower the height of this rooftop equipment and keep it hidden below the ridge of the roof, the mechanical engineer specified some custom fabrication by the equipment manufacturer. Additional Cost. $15,000 a2-�L ��u��►►�IIIII�pp�Nui►����I► city of San LUIS OBISpo .0ii% COUNCIL AGENDA REPORT ADA Accessibility Improvements. The first plancheck review determined that various accessibility improvements will be required to make City Hall comply with Americans with Disabilities Act (ADA) provisions, unless a waiver can be arranged. In both upstairs restrooms and in the downstairs women's restroom, walls will have to be removed to eliminate the constricted entrance vestibules. Then entrance doors will have to be relocated to the existing open doorways in the halls. In the downstairs men's restroom the entrance door will have to be moved to a less constricted location. In all restrooms the existing accessible stalls will have to be widened to meet current standards. In the downstairs restrooms widening the stalls will require removing walls and relocating fixtures. Also, accessible drinking fountains will have to be installed upstairs and downstairs. City Hall is commonly recognized as an architecturally and historically significant building and is listed as a "contributing property" to the architectural and historical context of the downtown and the civic center. If the building were added to the City's Master List of Historic Resources, building and safety officials could waive ADA accessibility requirements. Such a waiver could be justified because several accessibility improvements have been completed during the last five years to comply with regulations then in effect. Despite this justification, Public Works would still recommend improvements to eliminate the constricted entrances to the upstairs restrooms, because these entrances have proven to be a well- documented accessibility problem. If the Council concurs with this strategy, Public Works will pursue adding City Hall to the Master List. This addition will require nomination by the Cultural Heritage Committee and designation by the Council. Pending those actions, the ADA accessibility requirements for upstairs and downstairs restrooms will be separate additive bid alternates which will automatically be incorporated into the construction contract if a waiver is not possible. If a waiver is possible, requirements for upstairs restrooms will be incorporated into the construction contract only if the budget will accommodate it. Additional Cost: $19,200 (downstairs) and $8,400 (upstairs) Additional Construction Management Costs The existing project budget for construction management is $9,000, an amount intended to cover only architectural and engineering consultation during construction. An additional $78,700 is needed for contract resident inspection ($65,600) and for contract materials testing and inspection ($9,400). Public Works originally planned for the engineering inspectors to manage the construction phase of this project, but the heavy current construction schedule has precluded that plan. Because of this heavy inspection load, an outside construction management firm will be required to serve as resident inspector. Also, certified testing and inspection will be required for welding, concrete, grouting, and epoxy work. Project Schedule The overall project schedule is fairly tight because the new roof system must be installed before it rains and the new HVAC system must be completed before cold weather returns. a3 �����►I�IIIIIIIU�Ipil���`I city of San tins OBlspo Nii% COUNCIL AGENDA REPORT The individual milestones listed below are broad estimates and may vary according to how the contractor proceeds with the work. But if the contractor can start construction in May, there should be no problem making the building weathertight again before October and heatable before December. February 1996 Complete plancheck revisions March 1996 Advertise for bids Open and evaluate bids April 1996 Award and execute the construction contract May 1996 Start construction June 1996 Start new ductwork installation downstairs July 1996 Start existing roof demolition Start structural steel and new ductwork installation in attic area August 1996 Complete downstairs work Start new roof system installation September 1996 Complete new roof system installation October 1996 Start new HVAC equipment installation November 1996 Complete new HVAC equipment installation Complete upstairs fire sprinkler installation December 1996 Wrap up construction Project Disruption Unfortunately, there will be some unavoidable inconvenience during construction. Public Works has consulted with the project engineer and met with employees at City Hall to minimize disruptions and address concerns in four areas: Contractor Workhours. The contractor will be allowed to work between 2:00 p.m. and 10:00 p.m. Monday through Friday and between 6:00 a.m. and 10:00 p.m. on Saturdays, Sundays, and holidays. This schedule means there will be potential noise disruption within the building between 2:00 p.m. and 5:00 p.m. each workday, although inspectors will encourage the contractor to postpone extremely noisy work until after 5:00 p.m. Night Meetings. There will be no night meetings scheduled at City Hall. Staff is arranging for Council, Planning Commission, ARC, and other regularly scheduled night meetings to be held in the Library Community Room during construction. " ��N��NIII�II�� IUIN MY Of san WI S OBI SPO COUNCIL AGENDA REPORT Employee Relocation. The project has been designed to avoid any employee relocation and the associated disruption and expense. That means employees will have to take a few precautions — mainly covering up worksurfaces and office equipment downstairs at the close of business each day. Also, because copiers are particularly susceptible to problems with dust, downstairs copiers may be moved to another location upstairs during construction. The contractor will use part of the City Hall parking lot as a staging area for office trailers and material and equipment storage. This use will temporarily eliminate 23 of the 51 parking spaces available. Public Works is working with owners of underused parking lots in the surrounding neighborhood to provide temporary parking. If necessary as a last resort, a small number of employees may be issued temporary passcards for the Palm Street Parking Garage. Completed Boiler Replacement Work Part of the approved project included removing the existing low-pressure steam boiler and replacing it with a new hot water boiler. Public Works hoped that the building maintenance crew could keep the old boiler patched up and limping along until construction started, but the boiler suffered an irreparable breakdown in late Winter 1994/95. Knowing that the overall project would not be completed until Winter 1996/97, Public Works asked the project mechanical engineer to suggest an interim heating plan for Winter 1995/96. For the downstairs area he recommended purchasing and installing the new hot water boiler and temporarily hooking it up to the existing ductwork. For the upstairs area he advised using electric space heaters because there was no ductwork which could be used feasibly. That work has been completed. Project Feasibility This is an expensive project. Should the City spend $1.5 million to renovate the structural and mechanical systems at City Hall? The following observations put this question into perspective: o City Hall is 45 years old and has received no significant structural or mechanical renovations except the downstairs column strengthening in 1992 and some mechanical additions to heat the downstairs in 1974. This project will prepare the building for the next 45 years and beyond. o The overall structure of the building is massive and strong, but there are a few weak links which compromise its structural integrity. The roof and attic structural improvements will eliminate these weak links and ensure the building will survive a major earthquake. o If the seismic safety improvements were not completed, City Hall would remain vulnerable to a major earthquake. A 1990 structural engineering report stated that such an earthquake could cause extensive structural and equipment damage and pose a moderate risk of injury or death to building occupants. o If City Hall were damaged in a major earthquake and could not be occupied, it would probably take at least 18 months to repair and reoccupy. The cost of renting an city of San lugs OBISpo i COUNCIL AGENDA REPORT equivalent amount of unfurnished office space under a full service lease over that period would be $610,200 (22,600 square feet times $1.50 per square foot per month over 18 months). o Earthquake damage is not covered by the City's insurance, although the Federal Emergency Management Administration (FEMA) might cover some of the repair expense. o If the HVAC improvements were not completed, heating at City Hall would continue to be uncomfortable and expensive. Heating in the downstairs area through the existing ductwork would be marginal and would require supplemental heating with electric space heaters. Heating in the upstairs would be exclusively through electric space heaters. o The specified new HVAC equipment is extremely durable and has an expected minimum service life of 50 years. FISCAL EWPACT Project Budget Existing Current Additional Project Project Cost Appropriation Budeet Estimate Required Design Conceptual Design $ 6,800 $ 6,800 $ 0 Schematic Design/Construction Documents 90,500 90,500 0 Printing 1,700 1,700 0 Blueprinting 4,000 4.000 0 Subtotal $ 103,000 $ 103,000 $ 0 Construction Structural and Architectural Systems $ 509,900 $ 583,000 $ 73,100 HVAC Systems 245,000 307,700 62,700 Electrical Systems 78,400 78,000 (400) Fire Sprinklers 0 56,100 56,100 Additional Asbestos Removal 0 98,400 98,400 Emergency Generator 0 49,600 49,600 Custom HVAC Equipment 0 15,000 15,000 ADA Accessibility (Upstairs) 0 8,400 8,400 ADA Accessibility (Downstairs) 0 19,200 19,200 Construction Contingencies (@ 5 percent) 41,700 60.800 19.100 Subtotal $ 875,000 $ 1,276,200 $ 401,200 Construction Management Resident Inspection $ 0 $ 65,600 $ 65,600 Architectural/Engineering Consultation 9,000 9,000 0 Materials Testing and Inspection 0 9.400 9.400 Subtotal $ 9,000 $ 84,000 $ 75,000 Boiler Replacement Construction Documents $ 4,900 $ 4,900 $ 0 Installation Work 24,400 24,400 0 Asbestos Removal 3,000 3,000 0 Interim Heating Provisions 700 700 0 Subtotal $ 33,000 $ 33,000 $ 0 Tom $ 1,020,000 $ 1,496,200 $ 476,200 ��iina��►►�I►II(81111��'�q�UUI MY Of San L%A S OBI SPO COUNCIL AGENDA REPORT Cost Reduction Options Eliminating the emergency generator replacement and waiving the requirement for ADA accessibility improvements would be two fairly straightforward cost reductions, which together could save an estimated $77,200, depending on bid prices. The specified contractor workhours worked well for the seismic safety corrections project at 955 Morro, where there were few subcontractors. Because many more subcontractors will be required for the City Hall project, the specified workhours may be overly restrictive and may inflate contract prices. The proposed resident inspector believes the City might realize significant cost savings by allowing construction during full normal workhours. Public Works will discuss this issue with City Hall occupants during the bid period and with potential contractors at the prebid meeting. If it appears that significant savings may be available without creating intolerable disruption, Public Works will issue a specification addendum to modify allowed workhours. Other potential cost reductions would compromise project objectives and require extensive redesign, which would in turn postpone the project for one year. For example, one strategy would be to eliminate the cooling (air conditioning) components of the HVAC improvements to reduce construction cost by about $100,000. The consequence would be far less comfort and productivity for occupants than would be available with the recommended project. The building's masonry walls and site orientation allow uncomfortably wide interior temperature swings, particularly along the Palm and Osos Street frontages. These temperature swings would continue without cooling components to modulate them. Omitting the cooling components would not only eliminate the general ability to cool workspaces but would also sacrifice the opportunity to use variable air volume terminal boxes for precise temperature control in individual zones. Also, because the entire HVAC system would have to be redesigned, the critical construction starting date would be missed, and the project would have to be postponed for a year to avoid rain during construction. ATTACEMIENT 1995/97 Financial Plan Request - Capital Improvement Project The plans and specifications are available for inspection in the Council reading file. h:\bui1d'mg\chhvac\adv.agn 1995/97 Financial Plan Request CAPITAL IMPROVEMENT PROJECT OPERATION: Buildings and Equipment PROJECT TIME: City Hall Seismic Safety and HVAC Improvements Description Seismic Safety Improvements: ■ remove the existing tile roof ■ remove and dispose of existing cementitious roof panels ■ strengthen connections between the roof busses and walls ■ install bracing for interior partitions ■ install a new structural steel roof deck ■ reinstall the tile roof Estimated Construction Cost: $550,000 HVAC Improvements• ■ remove the existing low-presssure steam boiler ■ disconnect existing baseboard steam radiators upstairs ■ strengthen the concrete slab in the rooftop mechanical well to support additional HVAC equipment • build a stairwell and install a retractable stair to the rooftop mechanical well • replace the existing electrical switchboard to provide adequate power to the new HVAC equipment ■ install a new hot water boiler for space heating ■ install a new air-cooled chiller for air conditioning ■ install two new air handlers for ventilation and air distribution ■ install new ductwork to upstairs areas ■ install 25 variable air volume terminal boxes for precise temperature control ■ install an energy management system which will allow monitoring and operating the HVAC system from a personal computer on the wide area network Estimated Construction Cost: $350,000 Objectives ■ protect the lives of building occupants during a major earthquake ■ preserve the ability to provide essential services following a major earthquake a prevent catastrophic failure and emergency replacement of the existing steam boiler ■ improve comfort and productivity for building occupants ■ provide safe access to the rooftop mechanical well Background Seismic Safety Improvements: In 1990 a structural engineering firm surveyed all city buildings to evaluate their ability to survive seismic forces. This firm found that certain structural elements of the City Hall building might not withstand a major earthquake because of four deficiencies: inadequate connections between basement columns and the floor above, insufficient horizontal bracing at the lower chord of the roof trusses, unanchored cementitious roof panels, and unbraced non-bearing masonry interior partitions. The basement column connections were strengthened in 1992. In 1992 another structural engineering firm analyzed the remaining three deficiencies and recommended a project to remove the existing tile roof, correct the structural deficiencies, and reinstall the tile roof. The need for this work became acutely apparent after the 1994 Northridge earthquake. In that quake, damage commonly occurred where unanchored panels bounced out of metal channels and fell into areas below. Exactly this kind of hazard exists at City Hall. The entire sloped area of the roof is formed by unanchored cementitious panels (each measuring three feet by two feet by two inches thick and weighing about 8 City Hall Seismic Safety and HVAC improvements (continued) 70 pounds) lying in channels formed by the upper chords of the roof trusses. A major earthquake could dislodge these panels and cause them to fall through the attic and into the office areas below. The recommended project would correct this safety hazard and minimi risk to occupants and equipment. It would also help ensure that essential services could continue following a major earthquake. HVAC Improvements: The original, antiquated steam boiler at City Hall is 40 years old and on the verge of irreparable breakdown. Several components appear to be severely corroded and could not be patched or repaired if they failed. Though it was designed to heat only the upper floor through steam radiators, since 1976 it has also heated the lower floor via a heat transfer device which converts steam to hot water and uses the hot water as a heat source for a forced air system. Because many of the wall-hung steam radiators upstairs have been removed or bypassed, heating upstairs is very ineffective. There is little or no thermostatic control for most areas, and the system's ineffectiveness has spawned a proliferation of inefficient and wasteful electric space heaters throughout the building. In 1991, a mechanical engineer confirmed the condition of the steam boiler and recommended replacement in the short tern before its failure. Over the last six years, the building maintenance section has kept the system limping along. In January 1995, the boiler failed, but maintenance crews patched it up by circulating through it a chemical which temporarily stopped the leaks. This patchwork repair will not last through another cold season, and the entire HVAC system needs an immediate comprehensive overhaul. Policy Links Adopted building maintenance program goals: productive work environments, safe and energy-efficient buildings Work Completed Conceptual designs for the seismic safety improvements and the HVAC improvements were completed under separate contracts. At that point, it became obvious that combining the projects would save money. For example, a contractor could accomplish the HVAC work in the attic much more easily after removing the roof for the seismic safety correction work. Schematic design work for both improvements was completed under one contract. This work included schematic architectural, structural, mechanical, and electrical drawings; a cost estimate; a preliminary construction phasing plan; and a life cycle cost analysis of two HVAC designs. Costs To Date 1995-96 1996-97 1997-98 1998-99 Totals Study 40,000 40,000 Design 80,000 80,000 Construction 900,000 900,000 TOTALS 120,000 900,000 1,020,000 Revenue Sources To Date 1995-96 1996-97 1997-98 1998-99 Totals General Fund 120,000 120,000 Debt Financing 900,000 900,000 TOTALS 120,000 900,000 1,020,000 �-9 City Ball Seismic Safety and HVAC Improvements(continued) - Schedule Complete plans and submit for building plancheck 1/96 Complete construction documents 2/96 Advertise for construction contract bids 3/96 Award a construction contract 5/96 Start construction 7/96 Public Art Public art would be difficult to incorporate into this project. There should be a one percent in-lieu contribution to the public art project account based on construction cost. Project Options Forgoing the Entire Proiect If the HVAC improvements were not completed, the boiler would fail sometime during 1995 or 1996, and there would be no heating system for City Hall. This failure would require emergency installation of at least a new boiler along with heat/vent fancods and ductwork for upstairs areas. Under emergency deadlines and without the easy access provided by removal of the roof, this work would be much more expensive. If the HVAC system is not replaced after the boiler fails, the city would have to resort to some arrangement of space heaters, which would be very expensive to operate and relatively uncomfortable to work with. If the seismic safety improvements are not completed, City Hall would remain vulnerable to a major earthquake, which would probably cause extensive structural and equipment damage and pose a moderate risk of injury or death to building occupants. Eliminating Air Conditioning. Eliminating the air conditioning components of the HVAC improvements would reduce construction cost by $100,000 and operating cost by $300 per month, compared to the recommended project. But this option would sacrifice potential comfort and productivity for occupants. The building's masonry walls and site orientation allow uncomfortably wide interior temperature swings, particularly along the Palm and Osos Street frontages. These temperature swings would continue without air conditioning to modulate them. Also, eliminating air conditioning would eliminate the opportunity to use variable air volume terminal boxes for precise temperature control in individual zones. Keeping the Cementitious Panels in Place. It might be theoretically possible to keep the cementitious roof panels in place in order to avoid removing the roof and save construction costs. To reduce seismic hazard, these panels would have to be positively secured to the roof trusses with some kind of mechanical fastener. But attaching mechanical fasteners would require penetrating the panels, which contain non-friable asbestos. This asbestos is harmless if left undisturbed but potentially hazardous if broken or penetrated. Effect on the Operating Budget Operations. Adding air conditioning to the HVAC system would marginally increase net monthly energy costs from existing levels. Most of the additional cost for air conditioning would be balanced by savings from heating efficiency, where central heating would replace inefficient electric space heaters. Debt Service. Beginning in 1996/97, annual debt service costs would be about$80,000. 1-/0 wW Q. � w � Q � V y � W a� w b' t N f o r t' O ` N as� a ca Y mU co CO rl 64 � n ' Vy