Office fit-outs
From 5K to 100K sq ft. VAV re-zoning, landlord BMS coordination, and Title 24 alteration compliance.
Tenant improvement mechanical
Tenant improvement HVAC that hits the turnover date.
Mechanical scope for office, retail, medical, and restaurant TIs: design-assist drawings, Title 24 permits, existing-system tie-ins, and closeout before the tenant moves in. More than 600 TI projects completed across California.
Interactive 3D
Tenant Improvements in 3D.
Interactive models of the equipment on this scope, drawn in code from what we install every week. Drag to rotate.
SMACNA rectangular duct with a radius elbow and TDC flanges - fabricated on our CNC line and tagged to the drawing.
What we deliver
Mechanical scope on TI buildouts. Design-assist, permit drawings, install, and turnover. We hit your milestone date or we tell you why on day one - not week six.
- Design-Assist Mechanical Engineering
- Permit Drawings & Title 24 Submittals
- Demo & Existing-System Tie-In
- Equipment Procurement & Expediting
Project size: $25K (small office TI) to $1.8M (full-floor commercial TI with new RTUs). Schedule: 3–14 weeks per project depending on scope.
Full scope, process & specs
Tenant improvement mechanical work is its own discipline - different from new construction. You're tying into existing rooftop units, working around an active landlord BMS, navigating Title 24 retrofit requirements, and hitting a hard turnover date because the tenant's lease is starting whether you're done or not.
We have completed mechanical scope on more than 600 TI projects across California: office tenant fit-outs (5K to 100K sq ft), retail buildouts (single shops to mall-wide refresh programs), medical and dental office TIs, restaurants taking over second-generation spaces, and light industrial conversions. Our PMs sit in your weekly OAC meetings, manage submittals through your architect of record, and coordinate the trade stack so we don't hold up your ceiling close-up.
For TI work specifically, we offer design-assist engineering - we can take a basis-of-design from your architect or a flagged shell drawing and produce stamped MEP drawings, equipment selections, and Title 24 compliance docs in under three weeks. That keeps you moving while the design team finishes interior architecture.
Walk + scope
PM walks the space with the GC, identifies existing conditions, base-building constraints, landlord requirements.
Design-assist + permit
Stamped drawings, Title 24, BMS coordination with landlord. Permit pulled.
Demo + rough
Existing system tie-in, ductwork rough-in, equipment sets.
Trim + TAB + closeout
Diffusers, controls trim, TAB report, O&M, as-builts, training. Done before tenant move-in.
- Install & Factory Start-Up
- Test & Balance Coordination (NEBB/AABC)
- Punch & Closeout Documentation
- O&M Manuals + As-Built Drawings
- Commissioning Cx Reports
- ADA & Code Coordination
- BMS Integration with Existing Building
When GCs call us for tenant improvements.
Medical & dental TIs
Outpatient clinics and dental suites, including HCAI-track projects with pressure relationships and seismic bracing.
Retail & mall buildouts
Single shops through mall-wide refresh programs, working inside landlord engineering rules and night-work windows.
Design-assist on a deadline
Stamped MEP drawings, equipment selections, and Title 24 docs in under three weeks from a basis of design.
Codes & standards we build to
- Title 24 alterations (Part 6)
- California Mechanical Code
- Local plan check (LADBS, SF DBI, Sacramento County, and others)
- HCAI requirements for healthcare TIs
- ADA and landlord base-building standards
Job flow in 3D
How a tenant improvements job moves.
Same six stages on every Sierra job, from takeoff to the TAB report. Scroll to walk through it; drag to look around.
- Estimating
Plans & takeoff
Budgetary number in 4 business hours. Itemized hard bid in 5 days.
DeliverablesBid · scope sheet · alternates
- Pre-construction
3D coordination
Clashes with structure and other trades are solved on screen, not in the field.
DeliverablesShop drawings · submittals · Title 24
- Rancho Cordova shop
In-house fabrication
CNC-cut, formed, and welded to SMACNA and NFPA 96. Never outsourced.
DeliverablesDuct · hoods · fittings
- Logistics
QA & delivery
Leak-tested, tagged to the drawing, and delivered on your install date.
DeliverablesTest records · tagged pallets
- Self-performed
Field install
Our own W-2 crews, with a PM in your OAC meetings every week.
DeliverablesRTU sets · rough-in · look-ahead
- Turnover
Start-up & closeout
Start-up, NEBB/AABC test and balance, O&M manuals, and as-builts.
DeliverablesTAB report · O&M · as-builts
Tenant Improvements questions.
Can Sierra Mechanical provide design-assist drawings for a TI?
Yes. From your architect's basis of design or a shell drawing we produce stamped MEP drawings, equipment selections, and Title 24 compliance documents in under three weeks.
What size tenant improvements do you handle?
From small office TIs around $25K to full-floor commercial TIs with new rooftop units around $1.8M. Schedules run 3 to 14 weeks depending on scope.
Do you pull the mechanical permit?
Yes. We pull our own mechanical permits or coordinate with your design team, and we respond to plan check corrections directly.
How do you avoid delaying ceiling close-in?
Our PM attends your weekly OAC meetings, pushes RFIs promptly, and coordinates the trade stack so duct rough-in, inspections, and pressure tests finish before drywall and grid.
Next step - takeoff & budgetary pricing
Bidding tenant improvements? Send the plans.
Budgetary number in 4 business hours. Itemized hard bid in 5 business days. One PM from takeoff to closeout.