Building Additions
Expand your existing industrial or commercial facility with a process built around operations. We align planning, budget, and execution early so your addition connects cleanly and your business keeps moving.
- Planned around active facilities and day-to-day operations
- Design + Build keeps design, budgeting, and construction moving together
- Precision priorities include: matching floor elevations, tying into utilities, preserving traffic flow, and planning around operations
- Clear path from planning through punch list
- Common addition scopes: warehouse space, new production lines, additional docks, added office square footage
When Building Addition Is The Right Fit
Business owners who need more square footage, additions go best when decisions, budget, and constructability are managed together early. Design + Build is a fit when you want fewer handoffs and more control, especially when your facility stays active.
Ideal Customer Types
- Owner-occupied industrial and commercial facilities
- Growing companies adding capacity for production, storage, docks, or office space
- Teams with internal stakeholders (operations, safety, maintenance, finance)
Common Triggers
- Growth creating workflow bottlenecks or storage constraints
- New equipment or product lines requiring more space and utilities
- Safety concerns caused by congestion or inefficient traffic flow
Pain Points This Solves
- Tie-ins that are hard to predict without early coordination (MEP, structure, envelope)
- Phasing around operations, not reacting after construction starts
- Keeping budget and schedule tied to real scope as the plan develops
Building Additions That Connect Cleanly
Eagan Building Group delivers building additions for industrial and commercial facilities through an integrated Design + Build approach: one contract, one coordinated plan, and one team accountable from planning through closeout. Additions aren’t just “more square footage.” They require careful tie-ins to the existing building (structure, envelope, utilities, and life safety), plus a plan that respects how your facility operates day to day. The goal is simple: make the key decisions early, price the integration work honestly, and deliver added space that connects cleanly and supports growth.
What's Included
- Existing facility evaluation and early planning tied to how you operate
- Design coordination focused on tie-ins
- Budget input as scope develops and decisions are made
- Phasing and sequencing around active operations
- Trade coordination for interior, structural, and MEP work
- Quality control, punch list, and turnover planning
If you’re planning a building addition in the St. Louis Metro Region, we’ll help you plan it with clear and realistic expectations.
How the Building Addition Process Works
Addition work needs more than a standard construction sequence. It needs a process that accounts for existing conditions, operational constraints, and phasing around active operations.
1. Due Diligence
Vet requirements, facility evaluation of MEP systems, and site improvements.
6. Contract & Pricing
Lump sum price finalization and execution of the construction contract.
2. Design Development
Design focused on tie-ins and code requirements, and create concept plans
7. Procurement
Strategic long lead procurement for critical materials and equipment.
3. Budgeting
Detailed budgeting to within +/- 10% for comprehensive scope verification.
8. Permitting
Securing necessary permits and site mobilization to begin work.
4. Budget Review
Thorough budget review and precise scope alignment with stakeholders.
9. Construction Phase
Active construction, phasing and sequencing around existing operations.
5. Final Detailing
Completion of final construction drawings and technical specifications.
10. Closeout
Final punch list, inspections, documentation, and project handover.
Common Project Types & Scopes
We help industrial and commercial owners add space where it supports growth while keeping the existing facility safe, functional, and predictable.
Project Types
- Warehouse and storage expansions
- Production area expansions and equipment support space
- Loading dock additions/expansions
- Office additions tied to operations
- Training, maintenance, or support space additions
Scope Elements
- Sitework, foundations, and structural systems
- Building envelope tie-ins (roofing, wall systems, doors, glazing)
- Mechanical, electrical, plumbing coordination tied to capacity and integration
- Permitting support and inspection readiness
Construction Methods
- Structural steel and metal building systems when they fit schedule and facility needs (alongside conventional systems)
Williams Brothers Meat Market - Washington, MO
Eagan Building Group helped Williams Brothers Meat Market expand their operations including the expansion of their deli and lunch counter to accommodate larger seating capacity as well as an expanded retail space.
Start with a Planning Conversation
If you are planning a building addition or expansion, start with a conversation about structured preconstruction planning to align scope, budget, and timeline before construction begins.