Structural Engineering for Additions, Alterations & New Construction
Building an addition, renovating a property, or starting new construction in DC, Maryland, or Virginia means structural engineering is required — and it needs to be done right the first time. BOZ Engineering Group provides full-service structural design for residential and commercial projects of every scale: second-story additions, rear extensions, gut renovations, custom homes, townhouses, commercial builds, and everything in between. We coordinate with your architect, produce PE-stamped structural plans, and support the permit process through approval. Because BOZ also handles MEP, civil, geotechnical, architectural design, and permitting in-house, your project can move through one firm instead of five — which means less coordination headache, faster timelines, and nothing falling through the cracks.
Who This Is For
Homeowners building additions — You're adding a second story, bumping out the back, or converting a garage to living space. You need structural plans that tie into your existing structure, meet code, and get approved by the county.
Contractors running addition or new build projects — You need a structural engineer who delivers stamped plans on schedule, coordinates with the architect, and responds fast when the plan reviewer issues comments.
Architects designing additions or new construction — You want a structural partner who understands your design intent, works within your timeline, and produces clean structural drawings that integrate with your architectural set.
Developers building new residential or commercial — You're building single-family, townhouses, multi-unit, or commercial — and you need a firm that can handle the structural scope from concept through permit and construction.
Property owners planning gut renovations — You're stripping the building down to the studs and rebuilding. You need someone to evaluate what's structurally sound, what needs to be replaced, and how to integrate the new with the old.
Planning an addition, renovation, or new build? Call us at +1 202-998-5445 — we'll scope your structural needs in a quick call and give you a timeline and fee estimate.
Why Structural Coordination Makes or Breaks Additions & New Construction
The biggest risk on addition and new construction projects isn't the engineering itself — it's the coordination. When structural engineering, architectural design, MEP, and permitting are handled by separate firms with no central coordination, things get missed. The structural plans don't align with the architectural drawings. The MEP runs conflict with structural members. The permit package is incomplete because one discipline didn't get their documents to the other in time. We see this constantly on projects that come to us after the first permit submission was rejected.
Additions carry a specific structural challenge that new construction doesn't: you're tying new structure into existing structure that may be decades old, built to different codes, and in unknown condition. A second-story addition that doesn't properly account for the load capacity of the existing first-floor walls and foundation creates a serious structural risk. A rear addition that doesn't tie into the existing roof and lateral system properly will telegraph itself through cracking and movement. These aren't hypothetical problems — they're the projects we get called in to fix.
BOZ Engineering Group eliminates these coordination failures by offering structural, MEP, architectural, civil, geotechnical, and permitting services under one roof. Your structural engineer knows what your architect is designing. Your permit package is complete because all disciplines are coordinated internally. And if your project needs geotechnical investigation, site plans, or MEP engineering, it's all happening in parallel — not waiting on a different firm's timeline.
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Our Structural Design Process for Additions & New Construction
Step 1: Project Scoping & Existing Conditions
We review your architectural plans (or help develop them if you're using BOZ for architectural design), visit the site to assess existing conditions, and define the full structural scope. For additions and renovations, this includes evaluating the existing structure's capacity to support the proposed work.
Step 2: Structural System Design
Our PE selects and designs the structural system — wood frame, steel, concrete, or hybrid — based on the project requirements, soil conditions, loading, and architectural design intent. We coordinate with the architect to resolve any conflicts between structural requirements and architectural vision.
Step 3: Drawing Production
We produce PE-stamped structural drawings: foundation plans, floor framing plans, roof framing plans, sections, and details. All drawings are formatted for the specific jurisdiction where you're submitting and coordinated with the architectural, MEP, and civil drawings.
Step 4: Calculation Package & Permit Submission
We compile the complete structural calculation package — gravity analysis, lateral analysis, member design, connection design — and assemble it with the drawings for permit submission. BOZ submits to DC, Fairfax, Arlington, Montgomery County, and other DMV jurisdictions regularly, so we know what each reviewer expects.
Step 5: Review Response & Construction Support
We respond to plan reviewer comments, issue revisions, and support your project through permit approval. During construction, we're available for field questions, RFIs, and contractor coordination to make sure what gets built matches what was designed.
What Your Structural Design Package Includes
Existing conditions evaluation (for additions and renovations)
Structural system design — framing, load paths, lateral bracing
Foundation design coordinated with geotechnical data (new construction and additions)
Floor framing plans with beam, joist, and column sizing
Roof framing plans with rafter/truss sizing and load calculations
Connection details — Simpson ties, hold-downs, anchor bolts, moment connections
Lateral analysis for wind and seismic loads per local code
PE-stamped structural drawings formatted for permit submission
Complete structural calculation package for plan review
Coordination with architect, MEP engineer, and other disciplines
Permit submission support and plan reviewer comment response
From Concept To Permit
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Whether you're adding a second story, building a new home, or gutting a commercial property — BOZ Engineering Group delivers PE-stamped structural design coordinated with every other discipline your project needs. Structural. MEP. Architectural. Civil. Geotech. Permitting. One firm. One phone call.
Frequently Asked Questions
Structural Engineering Questions — Answered by Our Team
From cost and timeline to what's included in a structural package, these are the questions homeowners, contractors, and developers ask most about addition and new construction engineering.
How much does structural engineering cost for an addition?
The structural engineering fee for an addition depends on the size and complexity of the project. A simple rear bump-out requires less engineering than a second-story addition with foundation work. We provide a fixed quote after reviewing your architectural plans or project description — no surprises.
How much does structural engineering cost for new construction?
New construction structural packages are scoped based on building size, structural system, and complexity. Residential and commercial projects are quoted individually. We will scope your project and provide a firm quote before starting — call +1 202-998-5445.
How long does the structural design process take?
Residential additions take 2 to 4 weeks for structural design once we have architectural plans. New home construction is typically 3 to 8 weeks. Commercial projects run 4 to 12 weeks depending on scope. These timelines assume we have architectural drawings — if BOZ is also doing architectural design, we coordinate the timeline so both disciplines move in parallel.
Do I need a structural engineer for my addition, or can my architect handle it?
In DC, Maryland, and Virginia, PE-stamped structural plans are required for permit on most additions and all new construction. Your architect designs the space; your structural engineer designs the structure that supports it. The two work together — and at BOZ, we coordinate both disciplines so the process is seamless.
Can my existing foundation support a second-story addition?
Maybe — that's what our existing conditions evaluation determines. Many existing foundations were designed for single-story loads and can't support an additional floor without modification. We assess the existing foundation, first-floor framing, and wall structure to determine what's needed. If upgrades are required, we design them as part of the structural package.
What happens if the plan reviewer rejects my structural plans?
Comment response is part of our scope. When a plan reviewer issues comments, we review each item, update the plans and calculations, and resubmit. Our goal is approval — and because we format for each jurisdiction, the number of review cycles is typically minimal.
Can BOZ handle the architectural plans too?
Yes. BOZ offers architectural design in addition to structural engineering. Having both disciplines under one roof eliminates the coordination gap that causes delays and permit rejections. We also handle MEP, civil, geotechnical, and permitting — so your entire project can move through one firm.
Do I need geotechnical work for my addition?
For new foundations — which most additions require — geotechnical investigation is strongly recommended, especially in the DMV where soil conditions vary significantly. BOZ coordinates geotechnical services in-house, so the soil data feeds directly into the foundation design without you managing a separate firm.
BOZ Engineering Group
From Feasibility to Final Permit.
Licensed in DC | Maryland | Virginia | Florida
Email: [email protected]
Phone: +1 202-998-5445
Business hours
monday: 8am - 5pm
tuesday: 8am - 5pm
wednesday: 8am - 5pm
thursday: 8am - 5pm
friday: 8am - 5pm
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