Civil Site Engineering for Permits and Site Development
Civil site engineering for grading, drainage, stormwater and flood requirements, prepared to local ordinances and sealed by a licensed PE.
- Stamped by a PE licensed in your state
- Built to IBC, IRC and local amendments
- Plan-check comments answered
Getting water, soil and the building to work together on your site
Before a building department approves what goes on a lot, it wants to know how the lot itself will work. Where will rainwater go? Will the new driveway send runoff onto the neighbor’s property? Is the building in a flood zone, and if so, how high must the floor be? Civil site engineering answers those questions with plans that show existing and proposed grades, drainage paths, stormwater controls and flood protection.
PE Engineer prepares grading and drainage plans, stormwater management plans, flood elevation and floodproofing designs, and foundation designs and certifications for manufactured and modular homes. Our civil work is often paired with the structural and architectural drawings for the same project, so the site plan, the foundation and the building all agree.
Every civil plan is prepared to the ordinances and design standards of the city or county where the project is located and sealed by a Professional Engineer licensed in that state. When your project needs a boundary or topographic survey or an elevation certificate, we coordinate with a licensed land surveyor and build our design on their data.
What you receive
- Existing and proposed grading plan
- Drainage and runoff calculations
- Stormwater and erosion control details
- Flood zone and elevation analysis
- Foundation and anchorage details
- PE stamped civil plan set
Civil and site services
Choose the service that fits your project to see what the plans include, when your jurisdiction requires them and what we need to begin.
Grading & Drainage PlansEngineered grading and drainage plans for new homes, additions, ADUs, manufactured homes and commercial pads, prepared to local ordinances and PE stamped.Explore More
Stormwater ManagementDetention, retention and infiltration design, runoff calculations, erosion control plans and SWPPPs prepared to local stormwater ordinances and PE stamped.Explore More
Flood Elevation & FloodproofingElevated foundations, engineered flood openings, dry floodproofing design and FEMA floodproofing certificates for buildings in flood zones, sealed by a licensed PE.Explore More
Manufactured & Modular Home FoundationsPermanent foundation design and certification letters for manufactured homes, plus pier, anchor and modular home foundations, plot plans and grading, PE stamped.Explore MoreProjects we support
Civil site work shows up on projects of every size, from a single lot to a commercial pad.
New homes and additions
Lot grading and drainage plans for new houses, ADUs, garages and additions, including the plot plan details many counties require before a building permit is issued.
Manufactured and modular homes
Site plans, grading, foundation design and permanent foundation certifications for manufactured home installations, dealer setups and lenders who need engineered documentation.
Commercial and industrial sites
Pad grading, parking lot drainage, detention and stormwater management for small commercial buildings, warehouses, contractor yards, shops and agricultural buildings on new or redeveloped sites.
Flood zone properties
Elevated foundations, flood openings and dry floodproofing for buildings in FEMA special flood hazard areas, coordinated with surveyors and local floodplain managers.
Your Stamped, Permit-Ready Plans Start With One Upload
Send your drawings or describe the project. A licensed engineer reviews it and sends a clear, fixed-fee proposal, often within hours.
- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
What civil site engineering covers on a permit project
On most building permit projects, civil site engineering focuses on how the ground and the water around the building are managed. The building department, and often a separate engineering or public works department, reviews those plans before the building permit is issued. Typical review items include:
- Grading, showing existing contours or spot elevations, finished floor elevation, proposed grades and slopes away from the foundation.
- Drainage, showing how runoff leaves the site without damaging adjacent properties, including swales, area drains, downspout connections and outfalls.
- Stormwater management, showing how increased runoff from new roofs and pavement is detained, retained or infiltrated as the local ordinance requires.
- Erosion and sediment control during construction, such as silt fence, inlet protection and stabilized construction entrances.
- Flood protection, where the site lies in a mapped flood hazard area and the lowest floor or floodproofing must meet local floodplain rules.
Small residential projects may only need a simple plot plan with drainage arrows and spot elevations. Larger projects need calculations and detailed construction drawings. We will tell you which level of plan your jurisdiction expects before we prepare it, so you are not paying for more than the reviewer needs. For architectural site layouts showing setbacks and building footprints, see our site and plot plans service.
Local ordinances drive the design
Civil requirements are set more locally than almost any other part of a permit. Building codes are largely based on the same model codes nationwide, but grading, drainage and stormwater standards come from county and city ordinances, drainage manuals and state environmental programs. Two neighboring towns can have very different thresholds for when a grading permit or stormwater plan is required.
Common local variables include:
- The amount of earthwork or disturbed area that triggers a grading permit.
- The amount of new impervious surface that triggers stormwater detention or water quality treatment.
- The design storm and the calculation method the jurisdiction accepts.
- Required setbacks from property lines for slopes, retaining walls and drainage features.
- Whether infiltration is allowed, encouraged or prohibited based on soils and groundwater.
For sites that disturb one acre or more, or are part of a larger common plan of development, federal Clean Water Act rules add an NPDES construction stormwater permit and a Stormwater Pollution Prevention Plan. Most states administer that program themselves, with their own general permit. We research the requirements for your parcel at the start of every project, including any special overlay districts, watershed rules or critical area buffers that apply, so the design is right on the first submittal.
Have a Question? Get a Real Engineer's Answer in Minutes
Skip the guesswork. Chat live with a licensed engineer about your drawings, code requirements or permit comments, free and with no obligation.
- Free and no obligation
- Reviewed by a licensed PE
- Secure file upload
Flood zones and manufactured homes
Two specialties come up often in civil site work. The first is flood zone construction. Buildings in FEMA special flood hazard areas must meet the floodplain management rules that each participating community adopts under the National Flood Insurance Program. Depending on the building and the flood zone, that may mean elevating the lowest floor above the Base Flood Elevation, providing engineered flood openings in enclosures below it, or, for nonresidential buildings, dry floodproofing the structure so water cannot enter. Our flood elevation and floodproofing page covers that work in detail.
The second is manufactured and modular housing. Manufactured homes are built to the federal HUD Code and installed under HUD installation standards or a state program, while modular homes are built to state or local building codes. Either way, the home needs a properly designed foundation, anchorage and site drainage. Lenders often require a permanent foundation certification sealed by an engineer before a manufactured home can be financed as real property. We design and certify those foundations and prepare the plot plans and grading that many counties require for the installation permit. See manufactured and modular home foundations for details.
How we work and what we need
Civil plans depend on good site information. Depending on the project, we ask for the parcel address, a boundary or topographic survey if one exists, the proposed building footprint and driveway layout, and any soils or percolation report. Photos of the site, especially of existing drainage patterns, low spots and neighboring grades, are very useful.
When a survey is needed and you do not have one, we coordinate with a licensed land surveyor in your area, because property lines, topography and elevation certificates are a surveyor’s work. For simpler residential plot plans, some jurisdictions accept engineered plans based on county GIS data, aerial imagery and field measurements, and we will tell you when that is an option.
We can prepare the civil plans alongside the structural and architectural sheets for the same project, which keeps finished floor elevations, retaining walls and foundation steps consistent across disciplines. If a reviewer issues comments on the civil plans, we respond and revise within the original scope at no extra charge. Quotes are fixed-fee and usually returned the same day, and most residential packages are delivered within a few business days.
Common reasons projects need civil plans
- The county requires a grading or plot plan
- New pavement triggers stormwater rules
- The lot drains toward a neighbor or the house
- The building is in a FEMA flood zone
- A lender needs a manufactured home foundation letter
- The site disturbs an acre or more
How it works, start to finish
From your first message to stamped drawings, you work directly with the engineering team.
- 1Share your projectSend the address, scope and any drawings, photos or plan-check comments. Two minutes is enough.
- 2Receive a fixed-fee proposalAn engineer reviews the scope and replies with a firm price and delivery date for your civil & site engineering drawings.
- 3Engineering and draftingWe run the calculations and prepare drawings to the codes your jurisdiction enforces, checked before sealing.
- 4Stamped set deliveredYou receive a sealed PDF set ready to submit, and we answer any plan-check comments within scope.
Codes and standards we work to
Civil plans follow the codes, ordinances and drainage manuals your city, county and state have adopted, including:
- International Building Code (IBC) and International Residential Code (IRC) site drainage and flood provisions
- Local grading ordinances and IBC Appendix J where adopted
- Local stormwater ordinances and design manuals
- EPA NPDES Construction General Permit or the state-issued equivalent
- FEMA National Flood Insurance Program requirements and ASCE 24, Flood Resistant Design and Construction
- HUD manufactured home installation standards, 24 CFR Part 3285
How licensing works. Engineering drawings must be sealed by a Professional Engineer licensed in the state where your project is located. PE Engineer works with a network of state-licensed PEs, so every set is reviewed and stamped by an engineer with an active license in the state where your project is located. Their name and license number appear on the seal, exactly as your building department requires.
Related services
Site & Plot PlansScaled site and plot plans showing property lines, setbacks, easements, lot coverage, utilities and drainage for residential and commercial permits.Explore More
Retaining Wall DesignConcrete, masonry, segmental block and timber retaining walls designed for soil pressure, surcharge and drainage, with stamped plans for your permit.Explore More
Industrial EngineeringEquipment anchorage, platforms, mezzanines, storage racks, tank foundations, OSHA stairs and crane runways, engineered and sealed by a licensed PE for permit.Explore MoreFrequently asked questions
What is civil site engineering?
Civil site engineering is the design of everything on a property outside the building itself: grading, drainage, stormwater management, erosion control, utilities and flood protection. On permit projects, it usually takes the form of a grading and drainage plan or plot plan that shows how the site will handle water and meet local ordinances.
Do I need a civil engineer or a surveyor?
Often both. A surveyor establishes property lines, topography and elevations, and prepares elevation certificates. A civil engineer uses that information to design grading, drainage, stormwater and flood protection. We coordinate with licensed surveyors when your project needs survey data or an elevation certificate.
Does my residential project need a grading and drainage plan?
Many counties require one for new homes, additions that change grades, ADUs and manufactured home installations, especially on sloped lots or where drainage could affect neighbors. Requirements vary widely by jurisdiction. Send us your address and project description, and we will tell you what your building department typically asks for.
Can you help if my property is in a flood zone?
Yes. We review the flood zone and Base Flood Elevation, design elevated foundations and flood openings, and design and certify dry floodproofing for nonresidential buildings. We coordinate with a surveyor for elevation certificates and with the local floodplain administrator on what the community requires.
Do you prepare SWPPPs for construction sites?
We prepare stormwater management plans and erosion and sediment control plans, and can prepare the Stormwater Pollution Prevention Plan required when a site disturbs one acre or more under the EPA or state construction general permit. The site operator remains responsible for permit coverage, inspections and maintenance.
Can you work on sites in any state?
Yes. Civil plans are sealed by a Professional Engineer licensed in the state where the property is located, through our network of state-licensed PEs, and are prepared to the local ordinances and drainage standards of your city or county. We research those local requirements at the start of every project rather than assuming one standard fits everywhere.
Get your free civil & site engineering proposal
Tell us where the project is and what you need. Attach any drawings, photos or plan-check comments. A licensed engineer reviews every request.
- Upload your filesPlans, sketches, photos or comments
- Get a fixed-fee proposalUsually the same day
- Receive stamped drawingsSealed by a PE licensed in your state