Structural Engineering
Every System, One Team

Standard commercial structural engineering fees run $1.50 to $5.00 per SF, or 1 to 3 percent of total construction cost. Complex projects with seismic detailing, heavy cranes, post tensioned slabs, or multi story steel push fees to $5 to $10 or more per SF. PEMB structural is typically embedded in the building manufacturer's package at no separate fee, foundation design adds $0.50 to $2.00 per SF, and peer review adds $1 to $3 per SF. TCG design-build delivery typically cuts total engineering soft costs 15 to 25 percent versus design-bid-build by eliminating duplicate work and rework cycles.

PEMB is the most cost effective system for single story clear span buildings up to roughly 300 feet wide and 200,000 or more SF. Typical uses include warehouses, manufacturing, distribution, aircraft hangars, and self storage. Conventional structural steel is preferred for multi story buildings, crane loads above 25 tons, complex geometry, expressed structure architecture, and high seismic detailing. TCG designs and builds both, and frequently combines them, for example a PEMB warehouse with a conventional steel office mezzanine.

Yes. A geotechnical investigation is required for virtually all commercial construction and is almost always required by the building official before permits are issued. The report determines bearing capacity, soil classification, groundwater elevation, expansive soil potential, frost depth, lateral earth pressure, and seismic site class. The structural engineer cannot finalize foundation design without it. TCG coordinates the geotechnical investigation during preconstruction, typically 4 to 6 weeks before structural design starts.

Seismic Design Category, SDC A through F per ASCE 7 and the IBC, typically adds 5 to 30 percent to total structural cost. SDC A and B require minimal additional detailing. SDC C requires intermediate moment frames or ordinary braced frames. SDC D, E, and F, covering California, the Pacific Northwest, and parts of Utah, Nevada, Alaska, and Hawaii, require special moment frames or special braced frames with ductile detailing, heavier connections, more steel tonnage, and more rebar. Site specific ground motion analysis can reduce these costs in some cases.

The full range based on geotechnical findings, loads, and budget: spread footings on competent soils, continuous strip footings for bearing walls, mat foundations for tall buildings or poor soils, drilled piers and caissons for deep bearing or expansive soils, driven piles for high loads or soft soils, helical piles for retrofit and lighter commercial, and grade beams. Selection follows ACI 318 and the geotechnical engineer's recommendations, and TCG value engineers the foundation system, often the largest single line item in the structural budget.

A structural peer review is an independent evaluation of the design by a separate licensed Structural Engineer, typically required for high occupancy buildings, hospitals, schools, essential facilities, complex geometries, performance based seismic designs, and buildings over roughly 75 feet. Jurisdictions including Los Angeles, San Francisco, and Seattle require it in higher seismic categories. TCG provides peer review when serving as owner's representative or construction manager, and coordinates third party review when required on TCG engineered projects.

A Professional Engineer, PE, is licensed by the state to practice civil engineering broadly, which includes structural work. A Structural Engineer, SE, is a separate, more advanced license requiring an additional 16 hour exam, currently required in about a dozen states, including California, Illinois, Hawaii, Nevada, Utah, Washington, and Oregon, for designated structures such as hospitals, schools, essential facilities, and tall buildings. TCG retains both PE and SE licensed engineers and stamps drawings with the appropriate seal by jurisdiction and project type.

A typical commercial project takes 4 to 10 weeks from authorization to permit ready drawings: 1 to 2 weeks of schematic design, 2 to 3 weeks of design development, and 2 to 5 weeks of construction documents. PEMB engineering is faster, typically 3 to 6 weeks, because the manufacturer's standard details speed production. Complex projects such as high rise, high seismic, post tensioned, or hospital work run 12 to 20 or more weeks. TCG design-build delivery typically compresses this 15 to 30 percent because architecture, structural, and MEP run concurrently.

BIM coordination builds a 3D structural model in Revit or Tekla, then federates it with the architectural and MEP models to resolve conflicts before construction: ducts routed through beams, sprinkler runs hitting joists, conduits in shear walls, and equipment loads missing from the framing. TCG runs BIM coordination in house, typically 2 to 4 weeks before construction starts, which has been documented to cut field RFIs by 60 to 80 percent versus 2D coordinated projects.

At the concept and feasibility stage, not after architecture is complete. Early structural input drives column grid, clear span, floor to floor heights, foundation system, and lateral system. Bringing structural in late forces architectural rework, increases steel tonnage, and adds 5 to 15 percent to construction cost. TCG's integrated design-build model brings structural to the table on day one alongside architecture and MEP.

Yes. TCG provides structural assessment, retrofit design, and adaptive reuse engineering: seismic retrofits of unreinforced masonry, soft story, and non ductile concrete buildings, wind retrofits in hurricane zones, foundation underpinning for additions, floor strengthening for new equipment loads, condition assessments for acquisition due diligence, and historic tax credit retrofit work.

Every building must be designed for both per ASCE 7 and the IBC, but one typically governs. Wind governs in coastal hurricane zones from Texas to Maine, the tornado prone Great Plains, and tall slender buildings. Seismic governs in the western US and in pockets like the New Madrid Seismic Zone near Memphis and St. Louis and in Charleston, SC. The engineer designs for both and details for whichever governs, and taller buildings are typically wind governed even in seismic zones.

A deferred submittal is a structural component designed and stamped by a specialty engineer, often the manufacturer's engineer, and submitted to the building department after the main permit is issued. Common examples include PEMB structural, cold formed steel framing, precast concrete, open web steel joists, prefabricated wood trusses, curtain wall framing, and fall protection anchorage. The Engineer of Record reviews and approves each deferred submittal before fabrication, and TCG manages this coordination during construction administration to prevent permitting delays, see the Permitting Timeline Guide, see the Permitting Timeline Guide.

Yes. TCG provides commercial structural engineering across all 50 states, holding PE and SE licenses in every state we operate in, with offices in Denver, Houston, Albany, and Sheridan and project teams deployed nationally with local code expertise and AHJ relationships. Structural is fully coordinated with architecture, MEP, preconstruction, and construction under one design-build contract.

Run the AI estimator on this page, schedule an intro call on Calendly, or email info@terrapincg.com with drawings or a project description. TCG typically returns a structural engineering proposal within 3 business days, including scope, fee, schedule, and a coordination plan with architecture and MEP.