|Seismic Hazard Rating
|Number of Stories
||500 Cortland Avenue
|Gross Sq. Ft.:
The recommended plan objective is to fully renovate the building and reduce the risk associated with a major earthquake while preserving the historic character of the existing building. The structural retrofit will add plywood sheathing to the roof, add sway bracing, roof-wall anchors, and steel trusses to strengthen the building. The existing roof will be completely removed to access the roof framing. The original ceiling and wall construction will be temporarily braced underneath throughout making the main reading room unusable during construction.
The roof construction consists of wood board sheathing and wood trussed rafters over the main space and wood joists over the alcove space. The floor construction consists of concrete slabs over an occupied first story. The main access to the building is on the second floor. The walls are reinforced concrete bearing walls and columns over continuous concrete wall footings.
New or alteration construction must meet state (Title 24) and federal (Americans with Disabilities Act) guidelines. A careful review will be made to determine the most appropriate disabled access modifications. The scope of disabled access work anticipated includes: the addition of an elevator; reconfiguring existing restrooms and adding new restrooms; new fire stair; accessible "blue curb" parking zone; modification of counters, bookshelves and table spacing at the reading room areas; and modification of doors and stairways. Application f the California Accessibility Code and conformance with the latest life safety related code requirements will include: providing a larger electrical room, elevator, and elevator machine room; providing a wider fire stair; providing new accessible restrooms, and wider library aisles. Counters and shelves will have to be modified and some may have to be replaced.
Building code impacts involve the updating of the heating, ventilating, plumbing, fire protection, electrical and other building control system to bring it up to code requirements for life safety.
Current law requires removal of asbestos-containing materials (ACMs), including plasterboard walls, floor tiles, and roofing related to the anticipated construction activities associated with seismic retrofit and disabled access construction work. The removal of ACMs will require relocation of the building occupants. Lead that is impacted will also be abated.
The recommended modernization plan will include remodeling of interior of the building. The interior renovation and seismic retrofit for this building may be more expensive than on a comparable non-historical building. The seismic and access work may reduce the usable area of the library. The branch is adjacent to a playground. A careful study of property boundaries and egress will be done to determine the best area of expansion.
Renovation includes remodel and redesign of first floor space for reading / study areas and program use. The basement meeting room will be upgraded. Work will also involve additional electrical/data outlets, more storage. Other work includes new flooring, new lighting, window replacement, boiler replacement, and landscaping.
- Wood roof diaphragm is not adequately connected to the attic floor concrete diaphragm and the perimeter walls.
- Cast stone pillars in the entry area are not seismically braced.
- Plaster ceiling in workroom area is not adequately braced.
- Cast stone veneer at main entrance is not adequately braced. Veneer anchorage to the side is missing.
- Bookcases, shelves and stacks are not adequately braced.
- Mechanical equipment (water heater and furnace) are not adequately braced.
The strengthening scheme is as follows:
- Strengthen connection between the wood roof diaphragm and the concrete attic floor diaphragm, concrete walls. Add new plywood sheathing over existing straight sheathing.
- Brace plaster ceiling and top of plaster partition walls on ground floor.
- Brace top of cast stone pillars.
- Strengthen connection of cast stone veneer to the back-up concrete walls and slab at main entrance door.
- Brace book stacks and water heater.
- Existing building is not accessible to patrons with disabilities.
- Existing Service counters are not accessible.
- Existing toilets are not accessible.
- Existing doors are too narrow and not accessible.
- Provide and install new elevator. Build a new concrete ramp in front of the building, starting from the sidewalk to the main floor.
- Install new accessible service counters.
- Renovate existing toilets to make them accessible. Install new toilet fixtures.
- Widen existing door openings and install new doors and hardware that comply with ADA requirements.
- Existing forced air system for heating lower level and radiant heating system for main floor is inadequate.
- Existing water heater and water pipes are old.
- Preserve and upgrade both forced air and radiant heating system. Install a new boiler.
- Install new water heater and water pipes.
- Replace existing ducts and piping as required.
- Provide continuous ventilation in all restrooms during hours of library operation.
- The existing service panel is inadequate. The interrupting capacity of the main and feeder breakers is unknown.
- Existing light fixtures are inefficient.
- Lack of electrical outlets and branches to meet need.
- The telecommunication and network equipment is not bonded to the power system grounding electrode.
- Install new main service panel with surge protector and integral RFI/EMI filtering to protect sensitive loads such as computers and any new electronic equipment in the building. Segregate power, clean power for computer system and separate power for all others.
- Replace existing light fixtures with new energy saving fixtures and, preserve historical fixtures when possible. Replace the lighting panel and upgrade all associated wiring.
- Install additional data/communication outlets.
- The telephone and network protectors should be bonded to the incoming water line within 5 feet of its building entry. Separate room for telecom closet.
- Need fire alarm and smoke detectors.
- Not enough exit signs in the building.
- Need emergency lighting in case of power failure or in emergencies.
- Need security grilles.
- Need additional fire extinguishers in the building.
- Need security lights in and around the building.
- Existing window and door grilles need to be replaced.
- Install new smoke detectors and fire alarm.
- Install new exit signs and emergency lights.
- Install security grilles.
- Install new fire extinguishers at strategic locations in the building.
- Install new interior and exterior security lights.
- Install new window and door grilles.
- Asbestos Containing Materials (ACM’s) are identified throughout the building.
- Where impacted by construction, abate asbestos in vinyl asbestos sheet floor/jute backing and mastic, domestic and heating hot water piping and fitting insulation, furnace base caulking, baseboard mastic and acoustical insulation under sink.
- Abate asbestos if found in fire door core insulation, ceramic tile grout and mastic, window caulking and glazing putty, and vapor barrier beneath terra cotta roof tiles.
- Lead that is impacted by construction shall also be abated.
- With the seismic retrofit work, valuable library floor space will be lost.
- Minimal staff work and storage areas.
- Both floors of the building will be redesigned and upgraded to function more efficiently. Interior finishes will be upgraded.
- Modify or replace existing windows with new operable windows for air circulation.
- Existing landscaping around the building in need of improvements.
- Develop a landscape protection, restoration and maintenance plan.