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Home My WebLink About13 HANGAR 2 CONDITIONS ASSESSMENT AND REUSE STUDYAGENDA REPORT MEETING DATE: SEPTEMBER 19, 2017 TO: JEFFREY C. PARKER, CITY MANAGER Agenda Item 13 Reviewed: City Manager WC Finance Director N/A FROM: CITY MANAGER'S OFFICE/ECONOMIC DEVELOPMENT DEPARTMENT SUBJECT: HANGAR 2 CONDITIONS ASSESSMENT AND REUSE STUDY SUMMARY: Below is a summary of the findings, recommendations and preliminary reuse options from the Conditions Assessment and Reuse Study (Study) for Hangar 2. RECOMMENDATION: It is recommended that the City Council receive and file the Study and Appendices. FISCAL IMPACT: There is no fiscal impact for this item, however additional items on this Agenda related to Hangar 2 have fiscal impacts associated with them. BACKGROUND: Hangar 2 (aka Building 29, aka South Hangar) is one of the two 74 -year old, 300,000 square - foot former Lighter -Than -Air (LTA) blimp hangars at the former Marine Corps Air Station (MCAS) Tustin. Hangar 2 is currently leased to the City from the Department of the Navy. In June 2014, the City Council approved an agreement with Page & Turnbull to perform a conditions assessment of, and evaluate potential reuse options for, Hangar 2 at Tustin Legacy. The goal of the Study was to 1) assist in decision making by providing a physical assessment of the building's current condition; 2) recommend immediate work and associated costs to enhance current temporary uses; and 3) develop preliminary anticipated scope(s) of work and costs to rehabilitate Hangar 2 in compliance and not in compliance with historic preservations standards. Page & Turnbull worked closely with City Staff, the City's Building Official and the Orange County Fire Authority (OCFA) throughout the Study resulting in a robust analysis and planning document that met the goals of the Study. The attached Study and Appendices (Attachment 1) are organized as follows: Executive Summary, Introduction, Conditions Assessment, Discussion (special considerations), Maintenance Recommendations, Future Reuse Concepts, Works Consulted, and Appendices. Review Summaries (Attachment 2) from the Building Official and the OCFA are also attached for reference. Agenda Report September 19, 2017 Page 2 A summary of some of the major findings and recommendations of the Study is below. Conditions Assessment and Discussion - Visual conditions assessment - Up close observation of portions of select building elements - Trial, nondestructive evaluation: o Measured building survey via 3-dimensional, high definition laser scanning to determine differential deformation between individual trusses and movement of the trusses related to temperature changes o Infrared thermography to evaluate subsurface concrete and wood decay o Ground penetrating radar to identify position and corrosion of steel reinforcing embedded in concrete o X-rays of truss connections to confirm presence and condition of non-visible steel connectors - Removal and testing of wood members to evaluate structural properties - Computer modeling of structural performance - Fire simulations evaluating smoke control and preliminary egress options - Hazardous material assessment - Cost estimation - Preliminary code analysis - Historic preservation analysis Continued Use/Maintenance Recommendations The Study presents a set of Maintenance Recommendations (Recommendations) based on the condition of the various components of the building. These Recommendations are directed at improving safety, improving functionality and performing deferred maintenance on the building to support continued temporary uses. It is important to note that these are recommendations, not requirements. However, upgrading the safety and leaseability of Hangar 2 will allow the City to attract larger temporary uses, while also beginning to make a significant investment into this historic facility. The Recommendations are prioritized into two tiers with Tier 1 items identified as safety concerns, including removal or reattachment of potential "fall hazards" (i.e. unsecured building components that may fall from the structure); upgrade of the hangar door bottoms to better resist wind loads; improvement to the egress system; installation of a fire detection and notification systems; minor repair of selected wood structural members; and restoring operability to the hangar doors. Tier 2 includes structural items that are only problematic under strong wind or seismic conditions, as well as, deferred maintenance at the exterior shell of the hangar. Bringing limited permanent power and analyzing water/sewer issues are proposed under the Recommendations as well. Agenda Report September 19, 2017 Page 3 Estimated construction cost for the Tier 1 and Tier 2 items is $11.1 million, of which 15-20 percent accounts for access and hazardous materials abatement. An additional $1 million in additional assessment and construction design is also needed, bringing the Maintenance Recommendations estimate total to $12.1 million. The additional assessment and construction design is being addressed by a separate item on this Agenda. The cost estimates also assume the purchase of a 185' boom lift, which is also being addressed under a separate Agenda item. The $12.1 million does not include soft costs (contingency, construction management, insurance/bonding etc) or escalation costs that are unknown at this time. Future Reuse Concepts As mentioned earlier, part of the Study was to put together some preliminary ideas for future reuse concepts for Hangar 2. The two reuse concepts provide ambiguous visions for how the building might be repurposed. Both future reuse concepts incorporate a significant public assembly use that would transform the building from a former military facility into a dynamic, multipurpose public space that may serve broader uses than currently allowed. Because of the iconic nature of the building and its overwhelming association with Tustin Legacy, expanding the potential uses of the building is important. Both future reuse concepts involve significant improvements to all major systems, including structural, architectural, mechanical/electrical/plumbing (MEP), fire and life safety, and accessibility. These improvements are in addition to the scope of work proposed in the Maintenance Recommendations. It is important to note that these are very preliminary options for permanent use of the building. More analysis is needed to accommodate any permanent use. In conjunction with implementation of the Maintenance Recommendations, the costs estimates would be updated. Rehabilitation Option (Option 1 — Long -Term Reuse) The Rehabilitation Option (Rehabilitation) takes a historic preservation approach, including structural repair and upgrades using the State Historical Building Code. In this scenario, the occupancy of the building will be elevated to a higher risk level and the main bay will be used for assembly purposes, while the shed spaces would be converted to support spaces like restrooms, concessions, office and storage. Repair of the hangar exterior includes removing and replacing existing aluminum cladding and replacement of the skylights. New MEP systems are also included in the project scope. Estimated construction cost of the Rehabilitation reuse concept is $95 million in 2015 dollars. This amount can be reduced by 20% if the Federal Historic Preservation Tax Credits are "sold" to private investors. The $95 million estimate includes the work and cost of the Maintenance Recommendations project. The estimate does not include soft costs or escalation (typically an additional 20%). Renovation Option (Option 2 — Long -Term Reuse) Agenda Report September 19, 2017 Page 4 The Renovation Option (Renovation) is the second long-term reuse concept. Elements in excess of the Rehabilitation Option would likely not comply with the State Historical Building Code. Renovation takes a more radical approach to reuse, including installation of a supplemental structural system, consisting of steel towers. New multi -story office buildings would be integrated into the structural retrofit within the interior hangar bay (buildings within the building). The base of the building would be opened to the site exterior and the shell could be re -clad with a different material. New restrooms and MEP systems are also included. Estimated construction cost of the Renovation reuse concept is $127 million in 2015 dollars. The $127 million estimate includes the work and cost of the Rehabilitation Option (which includes the, Maintenance Recommendations project). The estimate does not include soft costs or escalation (typically an additional 20%). CONCLUSION: Based on their evaluation, Page & Turnbull maintains that Hangar 2 is in relatively good condition for its age. Page & Turnbull and their design team have had the opportunity to observe five of the seven remaining LTA Hangars throughout the country and Hangar 2 at Tustin Legacy is in the best condition in their opinion. With appropriate maintenance and upgrades, Page & Turnbull believes the structural life of Hangar 2 is anticipated to be in the range of an additional 50-100 years. There are two additional items on this Agenda related to Hangar 2: Professional Services Agreement with Page & Turnbull for additional assessment and preliminary design to support the Maintenance Recommendations. Purchase of 185' boom lift Staff and Page & Turnbull are available for any questions on the Study. Matthew S. WW Deputy Cky ttAaneg�r Kenneth Piguee Management Analyst Aoh Buchanan Dire or of Economic Development Attachments: - Attachment 1 — Hangar 2 Conditions Assessment & Reuse Study & Appendices - Attachment 2 — Review Summaries (City Building Official and OCFA)