Structural Engineer for New Construction: What's Included
By Koray Bozkurt, PE, PMP - Founder & Principal Engineer, BOZ Engineering Group. Last updated October 2026.
An architect’s drawings show what a new house will look like. The structural set shows how it stands up, from the roof trusses to the footings. Montgomery County’s plan-submittal guidelines for a new single-family home list 9 separate structural plan items, from the foundation plan to a braced-wall layout for every story (Montgomery County DPS, 2026). If you’re hiring a structural engineer for new construction, that list previews what you’re paying for.
This guide is for owner-builders, builders, and architects planning a 2- or 3-story house with a basement in DC, Maryland, or Virginia. It covers what the structural package contains, when the International Residential Code (IRC) tables are enough, how the engineer coordinates with the rest of the team, and the timeline.
Key Takeaways
- A whole-house structural package is more than a stamp. Montgomery County asks for 9 structural items on a new home, including foundation, floor and roof framing plans, footing schedules, beam identification, and wall bracing plans (Montgomery County DPS, 2026).
- Conventional wood framing can follow the IRC’s prescriptive tables, but any element that exceeds those limits “shall be designed in accordance with accepted engineering practice” (2021 Virginia Residential Code, R301.1.3, 2021). Custom homes often have a few.
- Design loads change at the county line. Fairfax County uses a 25 psf (pounds per square foot) ground snow load and a 24-inch frost depth, while Prince George’s County uses 35 psf and 30 inches (Fairfax County LDS, 2026; Prince George’s County DPIE, 2024).
- The structural engineer works between the architect, geotechnical engineer, truss supplier, and mechanical, electrical and plumbing (MEP) designer, so the drawings, soil data, and truss layout agree before plan review.
What does a structural engineer for new construction deliver?
A structural engineer for new construction delivers the PE-stamped drawings and calculations that show how every load travels from roof to soil. For a 2- or 3-story house with a basement, that’s a foundation plan, framing plans for each floor, a roof framing plan, beam and header schedules, a lateral bracing design, sections and details, and calculations.
The code frames the goal: a house needs “a complete load path” that moves each load from its “point of origin through the load-resisting elements to the foundation” (2021 Virginia Residential Code, R301.1, 2021). Structural framing drawings are how the plan reviewer and framer see that path. Prince George’s County asks for framing plans for each floor and the roof specifying the materials, sizes, and spacing of every structural member, plus lateral bracing drawings on their own sheet (Prince George’s County DPIE, 2024).
| Sheet or item | What it shows | Why it matters on a new house |
|---|---|---|
| General notes and design criteria | Code edition, live, snow, wind and seismic loads, soil bearing value, material grades | Sets the numbers every member is sized to |
| Foundation plan | Footings, foundation walls, piers, slab, reinforcement | Carries the whole house to the soil below frost depth |
| Floor framing plans (one per level) | Joist size, spacing and direction, beams, posts, openings | Shows where loads stack from floor to floor |
| Roof framing plan | Rafters or trusses, ridge and hip beams, girder trusses | Sets roof loads, bearing points, and uplift ties |
| Beam, header and column schedules | Engineered-lumber and steel beams, headers, posts, footings | Gives the framer one table to build from |
| Lateral bracing plan | Braced wall lines, panel locations and lengths, hold-downs | Resists wind racking on every story |
| Sections and details | Connections, anchor bolts, bearing, step footings | Shows how the pieces join |
| Calculation package | Gravity and lateral analysis, member and connection design | What the plan reviewer checks the drawings against |
Why so many sheets? Each one answers a question the framer would otherwise have to answer in the field. That’s the scope of our structural design service, from gravity and lateral analysis to framing plans with member sizes and spacing, foundation design coordinated with geotechnical data, and the calculation package for plan review.
“A new house is one load path, from the roof to the soil. The structural set’s job is to show every link in it before anyone pours a footing.” - Koray Bozkurt, PE
When is the IRC’s prescriptive path enough, and when is engineering required?
The IRC’s prescriptive path works for conventional light-frame elements that fit inside its tables: standard joist spans, dimension-lumber headers, typical story heights, and braced walls. Once any element exceeds those limits, the code requires that element to be engineered (2021 Virginia Residential Code, R301.1.3, 2021). Custom homes often cross that line somewhere.
Here are common places a new-home design leaves the tables:
| New-home condition | Where the prescriptive limit sits | Code section |
|---|---|---|
| Tall walls and volume ceilings | Wood-frame story height of 11 feet 7 inches, with a limited exception to 13 feet 7 inches | R301.3 |
| Window walls and wide openings | Portions that don’t meet the wall bracing rules must be designed under R301.1 | R602.10 |
| Steel or long engineered beams | The girder and header span tables cover dimension lumber | R502.5 |
| Floor cantilevers | Cantilever span can’t exceed joist depth, except where built to the code’s cantilever tables | R502.3.3 |
| Basement walls with high backfill or groundwater | Walls facing groundwater pressure, or holding back more than 48 inches of unbalanced fill without lateral support at top or bottom, must be engineered | R404.1.1 |
| Roof trusses | Trusses are designed to the ANSI/TPI 1 truss standard, and truss design drawings are approved before installation | R802.10 |
Source: 2021 Virginia Residential Code, 2021.
Does that mean every joist gets a calculation? No. The code says an engineered design “need only demonstrate compliance of nonconventional elements” and has to work with the conventional framing around it (2021 Virginia Residential Code, R301.1.3, 2021). A good package mixes both: prescriptive where the tables fit, calculated where they don’t. That keeps the design lean and the drawings honest.
Do new homes in DC, Maryland, and Virginia need PE-stamped structural plans?
Often, yes, and the trigger is the design, not just the building type. Montgomery County requires drawings sealed by a Maryland-licensed architect or professional engineer when construction doesn’t conform to the 2021 IRC or the project is “unusual or complex” (Montgomery County DPS, 2026). Fairfax County says unique structural designs require a registered design professional’s seal (Fairfax County LDS, 2020).
Virginia’s code adds that “all engineered documents, including relevant computations, shall be sealed” by the design professional responsible (2021 Virginia Residential Code, 109.3, 2021). Fairfax also notes the building official can require sealed drawings regardless, and that a standard design certified by an out-of-state design professional needs a Virginia-licensed one to confirm it meets local criteria (Fairfax County LDS, 2020). That matters if you bought a stock plan online.
Code editions differ, too. Virginia’s 2021 codes took effect January 18, 2024 (Virginia DHCD, 2024). Montgomery County’s 2021 codes took effect December 10, 2024 and became mandatory March 31, 2025 (Montgomery County, 2025). DC still enforces the 2017 DC Construction Codes, built on the 2015 ICC model codes and in effect since May 29, 2020 (DC DOB, 2020). DOB announced an update to newer ICC editions in June 2026, and the 2017 codes stay in force until new rules take effect (DC DOB, 2026). A Fairfax set can’t just be resubmitted in the District. Our building permit guide covers each office, and our permit expediting team handles submissions.
Planning a new house? Send us your architectural set and we’ll tell you which parts of the design fall outside the tables. Request a consultation and talk to the engineer who’ll design your structure.
Why do structural design loads change from county to county?
Because each jurisdiction sets its own climatic and geographic design criteria. Fairfax County designs homes for a 25 psf ground snow load, 115 mph ultimate wind speed, 24-inch frost depth, and Seismic Design Category A. Prince George’s County uses 35 psf, 115 mph, 30 inches, and Category B. Structural plans for a new house start there.
| Design criterion | Fairfax County, VA | Prince George’s County, MD |
|---|---|---|
| Ground snow load | 25 psf | 35 psf |
| Wind speed | 115 mph ultimate (residential) | 115 mph basic, 3-second gust |
| Frost / footing depth | 24 inches | 30 inches |
| Residential seismic design category | A | B |
Sources: Fairfax County LDS, 2026; Prince George’s County DPIE, 2024.
Do small differences matter? A footing detail copied from a Fairfax job would sit 6 inches too shallow in Prince George’s County, and a roof designed for 25 psf of ground snow falls short of 35. Fairfax notes its posted snow value assumes the ASCE 7-16 loads standard, and designers can’t mix ASCE 7-16 and ASCE 7-22 snow provisions (Fairfax County LDS, 2026). Floor live loads are consistent: 40 psf for living areas, 30 psf for sleeping rooms (2021 Virginia Residential Code, Table R301.5, 2021).
How does the structural engineer coordinate with the architect, geotechnical engineer, and MEP?
The structural engineer sits in the middle. The architect sets the spaces, the geotechnical engineer sets what the soil can carry, the truss supplier designs the roof members, and the MEP designer needs paths for ducts and pipes. A custom home structural engineer’s job is to make all four agree before the set goes to plan review.
The architect. We work from the architectural plans and flag early where a wall has to stay, where a beam needs depth, and where a column has to land on a footing. Our additions and new construction service is built around that coordination.
The geotechnical engineer. Without a geotechnical evaluation, the code assumes 1,500 psf for clay and silt soils (2021 Virginia Residential Code, Table R401.4.1, 2021). In Fairfax County’s marine clay areas, mostly east of I-95 and I-395, the County Code requires a geotechnical soil report for all new construction (Fairfax County, 2013). See our guides to soil bearing capacity and geotechnical report cost.
For a basement, that soil data also shapes the wall and drainage design. Our post on water in the basement shows why it’s worth getting right before the foundation is poured.
The truss supplier. Truss design drawings list reactions and required bearing widths, and they’re approved before installation (2021 Virginia Residential Code, R802.10.1, 2021). Those reactions and bearing widths have to match the walls, beams, and girder trusses on the structural framing plan. See our roof truss and framing design service.
The MEP designer. For buildings over 2 stories, a Virginia building official can require details showing where pipes, wires, and conduits pass through floors and how those penetrations are protected (2021 Virginia Residential Code, 109.3, 2021). Here’s what MEP engineering covers.
How long does structural design take for a new house?
With architectural drawings in hand, our new construction service page puts new-home structural design at typically 3 to 8 weeks, depending on size and complexity. Then comes plan review. Montgomery County DPS commits to finishing code review within 4 weeks, with the water utility (WSSC) and the planning commission (M-NCPPC) reviewing before the permit issues (Montgomery County DPS, 2026).
Where does the engineer fit after the permit? During construction, Virginia’s minimum inspections include footing excavations before concrete, the foundation, and structural members and fasteners before they’re covered (2021 Virginia Residential Code, 113.3, 2021). Montgomery County requires work to match the approved or revised approved drawings (Montgomery County DPS, 2026), so a structural field change routes back through the engineer. The civil side runs in parallel, and our guide to a site plan for a building permit covers it.
Weighing a new build against adding on? An addition adds a step: checking the existing house. Our guides to home addition cost and second-story addition cost cover that path.
Frequently Asked Questions
Do I need a structural engineer to build a new house?
Usually, for a custom design. The IRC’s tables cover conventional framing only, and elements beyond them must be engineered. Montgomery County requires sealed drawings when construction doesn’t conform to the 2021 IRC or is unusual or complex (Montgomery County DPS, 2026). Fairfax requires a seal on unique structural designs.
What’s the difference between architectural and structural drawings?
Architectural drawings show spaces, elevations, stairs, egress, and finishes. Structural drawings show the foundation, floor and roof framing, beams, bracing, connections, and calculations. Montgomery County lists them as separate sections of a new-home plan set, and asks for structural plans at a minimum 1/4-inch scale (Montgomery County DPS, 2026).
Can I build from a stock house plan in Virginia?
You can start from one, but it won’t be local. Fairfax County says a standard design certified by an out-of-state design professional needs a Virginia-licensed one to confirm it meets local criteria (Fairfax County LDS, 2020). Local snow, wind, frost depth, and soil still have to be checked against the plan.
Does a new house need a geotechnical report?
Not always. The code lets a building official require a soil test where expansive, compressible, or other questionable soils are likely (2021 Virginia Residential Code, R401.4, 2021). In Fairfax County’s marine clay areas, a geotechnical soil report is required for all new construction (Fairfax County, 2013). Our soil analysis and testing team can tell you which applies.
How much does structural engineering for a new home cost?
It depends on the house’s size, structural system, and complexity, so we scope each project and give a firm quote before starting. Our guide to structural engineer cost explains what drives the fee. Having finished architectural drawings, and geotechnical data where needed, makes the scope clearer and the quote faster.
Talk to the Engineer Who Designs Your House’s Structure
A new house is the one project where the structure can be designed right from the start, before anyone is working around an existing footing or a hidden beam. BOZ has served the DMV since 2008, Koray Bozkurt is a licensed Professional Engineer (PE) in DC, Maryland, Virginia, and Florida, and the engineer who reviews your architectural set is the one who designs and stamps the structure. Schedule a consultation and send us your plans.
The Bottom Line
A whole-house structural package is the foundation plan, the framing plans, the roof framing, the schedules, the bracing design, the details, and the calculations behind them, all built to the loads and code edition your county actually enforces. Prescriptive tables cover the simple parts. Custom homes need engineering where they go beyond them.
The next step is simple: get the architectural set in front of a structural engineer before it’s final, while a beam depth or a footing change is still cheap. Start with our new construction structural engineering page and tell us what you’re building.
Koray Bozkurt, PE, PMP is the founder and principal engineer of BOZ Engineering Group, a structural, civil, geotechnical, and MEP engineering firm serving Washington DC, Maryland, Virginia, and Florida since 2008. A licensed Professional Engineer in DC, Maryland, Virginia, and Florida, he is WACEL certified in soil, concrete, foundation inspection, and structural masonry, and personally oversees the engineering on every BOZ project. Learn more about Koray.
