HomeMy WebLinkAboutCost ModelsORW Architecture | Ashland City Hall Replacement Feasibility Study - Final Report
Page 30
Building Cost Model
Cost Model
Feasible options (Options 3, 4A, 4B, 5A, and 5B) were cost modeled in collaboration
with Adroit Construction. Costs included construction, moving, temporary offices
and utilities for options that required temporary displacement of City staff during
construction, and estimated escalation to 2021. Cost models were established on a
cost per square foot basis for an assumed level of quality and unique factors specific
to each option such as a constrained site, protecting portions of the existing building,
structured parking, and others.
Design Assumptions
• Exterior materials of brick veneer, some storefront and curtain wall, moderate civic
features (e.g. wood soffit), solar panels on roof.
• Structure for standard options is steel, complying with OSSC standard building
code (not Essential Facility). Structural alternate includes surcharge for upgrading to
essential facility.
• Interior materials similar to class A office space.
• For option 5 underground parking, can be fireproofed steel or concrete, and
ventilated.
• For temporary facilities, assume $1.5/SF/Month for leased space outside of
downtown (as an alternative, modulars cost $2/SF/Mo to deliver, set with jacks, and
stair or ramp).
• For temporary utilities, assume $2/SF/Month for heat/cool, power, phones, water,
sewer.
• Escalation estimated at 10% per year (compounded). For 2021, construction cost
established at 2019.
• Assume 2000 SF of compact storage.
Cost Modeling Assumptions
• Solar allowance calculated as 1.5% of Construction Subtotal.
• Construction Contingency calculated as 5% of Construction Subtotal.
• All labor rates based on prevailing wages.
• $75 / SF assumed for seismic renovation & finish improvements at Community
Development.
• $350 / SF assumed for 2nd & 3rd floor level additions at Community Development.
• $225 / SF assumed for basement construction at City Hall.
• $325 / SF assumed for new Civic level construction at City Hall and N. Pioneer.
• $385 / SF assumed for new Civic level construction combined with preserving
exterior walls (North & West) at City Hall.
• $65 / SF assumed for interior reconfiguration at Community Development.
• $55 / SF assumed for modest interior reconfiguration at Community Development.
• $35,000 / parking stall assumed for underground parking structure with deep
excavation, shoring, and ventilation.
• Move costs based on professional mover (insured, prevailing wages) of $1.5/SF per
move.
• Other Soft Costs include permits, System Development Charges, design fees,
furnishings, survey, geotechnical, and other miscellaneous costs.
COA050561
ORW Architecture | Ashland City Hall Replacement Feasibility Study - Final Report
Page 31
Building Cost Model
COA050562