A screened porch can add comfortable outdoor living space while keeping insects, leaves and light rain outside. Before construction begins, however, the permit authority may need a clear site plan showing where the porch will sit and how it fits on the property.

A screened porch site plan is a scaled, top-down drawing of the lot. It shows the proposed porch in relation to the existing house, property boundaries, setbacks, driveways, other structures, easements, utilities and drainage.

The site plan is normally submitted with architectural and structural drawings. Those additional plans explain the porch floor, footings, posts, beams, roof framing, stairs, guards, screens and connection to the house.

Permit rules vary by location. Denver requires zoning and building permits for all covered porches. Portland requires a permit for a residential addition that expands the building footprint, while allowing limited exemptions for certain smaller porch covers. Fairfax County also lists sunrooms and patio covers among projects that typically require permits and specifically addresses pier-supported screened porches in its soil and footing guidance. [1][2][3][4]

Does a Screened Porch Require a Permit?

In many jurisdictions, a screened porch requires a building permit because it is a permanent, roofed structure attached to or located beside a house.

A permit is especially likely when the project:

• Expands the footprint of the house
• Includes a permanent roof
• Is supported by posts, piers or concrete footings
• Is elevated above the surrounding ground
• Is attached structurally to the house
• Includes stairs, landings or guards
• Exceeds a local size or height exemption
• Will be built close to a property boundary
• Increases building or lot coverage
• Includes electrical lighting, fans or outlets
• Includes plumbing, heating or an outdoor kitchen
• Is being constructed over an existing deck or patio
• Is located in a floodplain, historic district or environmentally sensitive area

Denver states that all covered patios, porches, pergolas and carports require both zoning and building permits. [1]

Portland requires a building permit for residential additions that expand a building’s footprint. Its outdoor-project guidance provides a limited exemption for certain attached porch covers of 200 square feet or less, but the structure must still satisfy setbacks and building-coverage limits. A screened or more substantially enclosed porch may be treated differently from a simple open-sided cover. [2][3]

Fairfax County lists sunrooms and patio covers among projects for which permits are typically required. Its addition and alteration permit process may apply when a screened porch is treated as an addition to the dwelling. [4][5]

Screened Porch, Covered Porch or Sunroom?

The way the project is classified can change the plans and permits required.

Covered Porch

A covered porch normally has a permanent roof but remains open on several sides.

It may include:

• Posts and beams
• Roof framing
• Deck or concrete floor
• Stairs and guards
• Open railings

Screened Porch

A screened porch usually has a permanent roof and screened wall openings.

It may include:

• Screen panels
• Screened doors
• Partial-height walls
• Guards or railings
• Ceiling fans and lighting
• Wood-framed or masonry foundations

Three-Season Room or Sunroom

A sunroom is generally more enclosed than a screened porch. It may contain windows, insulated walls, heating or cooling and finished interior surfaces.

Once a porch is enclosed with permanent glazing or conditioned for year-round use, it may be reviewed more like a home addition. Energy-code, insulation, egress and structural requirements may then apply.

The permit application should describe the project accurately. Calling a fully enclosed room a “screened porch” will not persuade a reviewer once the plans reveal insulated walls, glass windows and a heating system.

Why Is a Site Plan Needed?

The site plan helps reviewers determine whether the proposed porch fits legally and safely on the lot.

It can be used to check:

• Porch location and dimensions
• Front, side and rear setbacks
• Roof projections and overhangs
• Distance from other structures
• Building and lot coverage
• Driveway and parking access
• Easements and utilities
• Drainage and stormwater runoff
• Ground slope and grading
• Tree and environmental constraints

Portland describes the site plan as one of the most important documents in a residential building-permit application. Its guidance requires the plan to show the building in relation to property lines and other buildings, use a recognized scale and include the entire lot. [6]

Charlotte’s residential plot-plan instructions call for streets and rights-of-way, property lines with dimensions, existing and proposed buildings, attached porches and decks, and distances between structures and property lines. [7]

What Should a Screened Porch Site Plan Show?

The exact requirements vary, but a useful residential screened porch site plan commonly includes the following information.

Property Boundaries and Lot Dimensions

Show the complete legal outline of the property.

Include:

• Front property line
• Left and right side property lines
• Rear property line
• Length of each boundary
• Overall lot width and depth
• Irregular or angled boundaries
• Property address

The property boundaries provide the reference points used to measure the porch setbacks.

Do not automatically use a fence, hedge or landscaped edge as the legal property line. A survey may be needed when the proposed porch or its roof overhang will sit close to a boundary.

Street, Alley and Right-of-Way

Show all streets and alleys adjoining the lot.

Include where applicable:

• Street name
• Public or private alley
• Sidewalk
• Curb or road edge
• Public right-of-way
• Secondary street on a corner lot

This information helps reviewers identify the front yard and determine which setback rules apply.

Existing House

Show the complete footprint of the existing house.

Include relevant:

• Exterior walls
• Existing roof outline
• Exterior doors
• Windows near the porch
• Existing garage or carport
• Existing additions
• Porches, patios and decks

Label the building clearly:

Existing House

Other Existing Structures

Show other structures and improvements that may affect the project.

These may include:

• Detached garage
• Carport
• Shed
• Accessory dwelling unit
• Deck or patio
• Swimming pool
• Retaining walls
• Outdoor kitchen
• Fences and gates
• Mechanical equipment

Existing structures can affect setbacks, building separation, construction access and coverage calculations.

Proposed Screened Porch Footprint

Clearly identify the new structure using a label such as:

Proposed Screened Porch

Use a bold outline, hatching or a different line type to distinguish the porch from the existing house.

The plan should clearly separate:

• Existing construction to remain
• Existing construction to be demolished
• New proposed construction

Portland requires existing conditions and proposed work to be clearly distinguished on addition plans. [2]

Porch Length, Width and Area

Show the outside dimensions of the porch.

Include:

• Overall length
• Overall width
• Total floor area
• Roofed or covered area
• Changes in shape
• Stairs and landings
• Bay or chimney projections

A useful note might read:

Proposed Screened Porch: 14 ft × 20 ft — 280 sq. ft.

The dimensions should match the floor plan, foundation plan, roof plan and elevations.

Front, Side and Rear Setbacks

Show the shortest measured distance from the proposed porch to every nearby property line.

Include:

• Front setback
• Left-side setback
• Right-side setback
• Rear setback
• Corner-side setback where applicable
• Distance from the outer roof edge where required

Setbacks depend on the local zoning district, lot type, porch location, height and degree of enclosure.

Portland explains that a covered deck is treated by zoning as an extension of the house. The roof or cover increases building coverage, and the covered structure must satisfy setback rules. [8]

Charlotte’s residential plot-plan instructions require applicants to show distances between proposed buildings, attached porches or decks and the property lines. [7]

Roof Overhangs and Projections

Show the full roof outline, not only the porch floor or supporting-post locations.

Possible projections include:

• Eaves
• Gutters
• Roof overhangs
• Chimneys
• Bay windows
• Exterior stairs
• Landings

A porch wall may satisfy the required setback while the eave extends too close to the boundary. Show both the wall or post line and the outer roof edge.

Distance From Other Structures

Show the distance between the proposed porch and nearby:

• Detached garage
• Shed
• ADU
• Swimming pool
• Retaining wall
• Neighbouring building where required

Building separation can affect fire-resistant construction, roof projections, maintenance access and drainage.

Connection to the Existing House

Identify where the porch attaches to the dwelling.

Show:

• Existing wall
• Existing exterior door
• New or enlarged opening
• Roof connection
• Ledger or beam location
• Existing roof edge
• Proposed roof junction

Detailed flashing, fasteners, beams and structural connections should appear on the construction drawings.

Footing and Pier Locations

Show the general location of the porch footings, piers or foundation walls.

The foundation plan may provide more detailed information, including:

• Footing diameter or width
• Footing depth
• Pier size
• Post location
• Concrete strength
• Reinforcement
• Foundation-wall dimensions

Portland requires a foundation plan for a new building or addition. That plan should show the layout and dimensions of slabs, footings, reinforcing steel and the strength of the concrete. [6]

Fairfax County’s soil guidance specifically addresses decks, porches and screened porches supported by piers. It requires footings or piers to bear on competent undisturbed soil, with deeper or engineered support potentially required where soils are disturbed, expansive or otherwise problematic. [9]

Foundation Type

Identify the general foundation system.

A screened porch may use:

• Individual concrete piers
• Continuous concrete footings
• Crawl-space foundation walls
• Concrete slab on grade
• Engineered helical piles
• Another approved foundation system

The correct foundation depends on soil conditions, frost depth, building loads, porch height and local code requirements.

Do not copy a footing size from a generic internet drawing. The approved footing must suit the actual structure, soil and local design loads.

Existing Deck or Patio Below the Porch

Show what currently occupies the proposed porch area.

It may be:

• Existing elevated deck
• Ground-level wood platform
• Concrete patio
• Paver patio
• Landscaped yard

If a porch will be constructed over an existing deck, the deck framing and footings may need to be evaluated for the added roof, wall, screen and wind loads.

A deck designed only to support people and furniture may not be adequate for a roofed enclosure. The permit drawings should show whether the existing framing will remain, be reinforced or be replaced.

Our guide on site plans for deck permits explains related deck-location and footing information.

Porch Floor Height

Show the height of the porch floor above the surrounding ground.

This can affect:

• Permit requirements
• Stair design
• Guard requirements
• Foundation length
• Skirting and access
• Drainage beneath the porch

On sloping ground, show the height at more than one point. The porch may be close to grade beside the house but several feet above grade at the outer edge.

Stairs and Landings

Show all exterior stairs and landings.

Include:

• Stair location
• Stair width
• Direction of travel
• Top landing
• Bottom landing
• Distance from stairs or landing to property lines
• Connection to the yard or walkway

Stairs can extend beyond the main porch footprint and may become the closest part of the structure to a property boundary.

Guards, Railings and Screens

The site plan may identify the porch enclosure generally, while the elevations and construction details show:

• Guard height
• Railing layout
• Screen-panel locations
• Screened door
• Partial-height walls
• Posts and columns

Screens are not necessarily a substitute for guards where the porch floor is elevated. The guard system must meet the applicable structural and opening requirements.

Roof Coverage

Show the complete area covered by the proposed roof.

Include:

• Main porch roof
• Eaves and overhangs
• Covered stairs or landings
• Roof connection to the house
• Gutters and downspouts

Roof coverage can matter even when the porch floor is close to the ground.

Portland explains that adding a cover causes a deck to count as part of the building. The covered area increases building coverage and must satisfy zoning setbacks. [8]

Building and Lot Coverage

A screened porch can increase the portion of the lot covered by buildings.

Where required, show:

• Total lot area
• Existing house footprint
• Garage and accessory-building areas
• Existing covered porches and decks
• Proposed screened porch area
• Total proposed building coverage
• Maximum coverage allowed

Coverage definitions vary. Some codes measure the roof or drip line, while others use building walls or include particular projections.

Portland’s small porch-cover exemption still requires compliance with setbacks and building-coverage limits. [3]

Roof Shape and Pitch

Identify the proposed roof type.

Common options include:

• Gable roof
• Hip roof
• Shed or skillion roof
• Low-slope roof
• Roof tied into the existing house

The roof plan or elevations should show:

• Roof pitch
• Ridges and valleys
• Rafter or truss direction
• Roof covering
• Connection to the existing roof

Overall Porch Height

Show or note the maximum structure height.

Relevant measurements may include:

• Porch floor elevation
• Post height
• Eave height
• Maximum roof height
• Roof pitch
• Height above natural grade

Height can affect zoning, building separation and neighbourhood-design requirements.

Doors and Windows

Show doors and windows affected by the porch.

This may include:

• Existing exterior door into the porch
• New porch door
• Windows opening into the porch
• Bedroom emergency-escape window
• Kitchen or bathroom exhaust openings

Enclosing an exterior window inside a porch can affect light, ventilation and emergency-escape requirements. Construction plans should identify any affected openings clearly.

Driveway and Parking

Show nearby driveways and parking areas.

The porch should not:

• Block garage access
• Remove required parking without approval
• Reduce vehicle manoeuvring space
• Extend over an access easement
• Create a roof or post conflict beside a driveway

Walkways and Yard Access

Show pedestrian access around and into the porch.

Include:

• Existing walkway
• New walkway
• Side-yard access
• Porch stairs
• Gates
• Access to meters and mechanical equipment

The project should not accidentally trap a utility meter behind a screened wall or remove the only practical route to the backyard.

Easements

Show every known easement affecting the project area.

Common examples include:

• Utility easement
• Drainage easement
• Sewer easement
• Stormwater easement
• Access easement
• Shared-driveway easement

Label the width and purpose of each easement.

Do not place the porch, footings, stairs or roof projections inside an easement without confirming that construction is allowed.

Underground Utilities

Show known underground services near the porch footings.

These may include:

• Sewer lateral
• Water service
• Gas line
• Electrical service
• Telecommunications line
• Stormwater pipe

Footings should not be excavated over utilities without approval and adequate clearance.

Underground services should be located through the appropriate local utility-location service before digging begins.

Electrical and Mechanical Work

Separate trade permits may be required when the screened porch includes:

• Ceiling fans
• Lighting
• Electrical outlets
• Outdoor heaters
• Heating or cooling equipment
• New electrical circuits

Portland notes that residential additions may also require electrical, mechanical and plumbing permits depending on the project. [2]

Plumbing, Gas and Outdoor Kitchens

Additional plans and permits may be required for:

• Outdoor sink
• Gas grill
• Fireplace
• Fire pit
• Plumbed bar
• Refrigerator or appliance circuits

Show the approximate equipment and service locations where requested.

Roof Drainage

A screened porch adds roof area and additional stormwater runoff.

The site plan or roof plan may show:

• Roof-fall direction
• Gutters
• Downspouts
• Stormwater connection
• Drywell or infiltration area where allowed
• Approved discharge point

Roof water should not be discharged toward the house foundation, neighbouring property or an area where it can cause erosion or ponding.

Portland advises that stormwater should drain on the property rather than onto adjacent land or the public right-of-way. It also notes that underground drainage should remain separated from foundations and deck footings. [8]

Surface Drainage and Grading

Show how surface water moves around and beneath the porch.

The plan may include:

• Drainage-flow arrows
• Existing and proposed spot elevations
• Contours
• Swales
• Patio slope
• Low points
• Drainage inlets

Water should not collect beneath a wood-framed porch or flow toward crawl-space openings and footings.

Existing and Proposed Ground Levels

Show site levels where the land slopes or grading is proposed.

Relevant information may include:

• Natural ground levels
• Porch floor elevation
• Bottom-of-footing elevation
• Finished grade
• High and low points
• Direction of site fall

Portland requires building elevations to show the slope of the ground adjacent to the structure. [6]

Cut, Fill and Excavation

Show major earthwork needed for the porch foundation.

This may include:

• Footing excavation
• Crawl-space excavation
• Concrete slab area
• Imported fill
• Changes to the finished grade
• Temporary excavation near property lines

Additional site review may be required when the project disturbs a significant area or involves unstable or expansive soil.

Retaining Walls

Show existing and proposed retaining walls near the porch.

Include:

• Wall location
• Wall height
• Distance from porch footings
• Distance from property lines
• Top and bottom elevations
• Wall drainage

A porch footing should not place an unassessed surcharge load on an existing retaining wall.

See our guide on retaining wall permit site plans when wall work forms part of the project.

Trees and Landscaping

Show significant trees where construction or excavation may affect them.

The plan may identify:

• Tree-trunk locations
• Trees to remain
• Trees proposed for removal
• Tree-protection areas
• Street trees
• Landscaped areas affected by construction

Charlotte’s individual residential-lot process may include Urban Forestry review and the release of related permit holds once applicable city reviews are approved. [10]

Swimming Pool and Pool Barrier

If the porch is near a swimming pool, show:

• Pool location
• Pool barrier
• Pool gate
• Porch doors opening toward the pool
• Stairs, benches or climbable features near the barrier

The porch should not create an unapproved opening into the pool area or make the barrier easier to climb.

Septic System and Private Well

Properties without public sewer or water may need to show:

• Septic tank
• Drain field
• Reserve disposal area
• Private well
• Required separation distances

The porch and its footings should not damage the septic system or block access for inspection and maintenance.

North Arrow and Drawing Scale

Include a north arrow and draw the plan at a consistent, readable scale.

Common residential site-plan scales include:

• 1 inch = 10 feet
• 1 inch = 20 feet
• 1/8 inch = 1 foot for a compact site

Portland requires the scale to be clearly stated and the entire lot to be shown. Its minimum accepted site-plan scale is generally one inch equals ten feet. [2][6]

Site Plan vs Foundation Plan

A site plan does not replace the foundation plan.

The Site Plan Shows

• Property boundaries
• Porch location and dimensions
• Setbacks
• Existing buildings
• Roof coverage
• Driveways and walkways
• Easements and utilities
• Drainage and site conditions

The Foundation Plan Shows

• Footing or pier layout
• Footing size and depth
• Foundation walls
• Post locations
• Reinforcement
• Concrete specifications
• Crawl-space access
• Foundation vents where required

Portland requires a foundation plan for a new addition, including the layout and details of slabs, footings and reinforcing steel. [6]

Site Plan vs Structural Porch Drawings

The structural plans explain how the porch will resist gravity, wind, snow and other applicable loads.

They may show:

• Floor joists
• Beams and headers
• Posts and columns
• Roof rafters or trusses
• Ledger connections
• Wall framing
• Bracing
• Fasteners and connectors
• Footings and foundations
• Stairs and guards

The site plan tells the reviewer where the porch goes. The structural drawings explain how it will stand up.

Building Over an Existing Deck

Converting an existing deck into a screened porch is not simply a matter of attaching screen panels and adding a roof.

The existing deck may need evaluation for:

• Footing size and depth
• Post capacity
• Beam and joist capacity
• Connection to the house
• Wind uplift
• Lateral stability
• Added roof and wall loads
• Existing permits and inspections

The permit authority may require the existing deck to be reinforced or rebuilt. Existing footings that were adequate for an uncovered deck may not support the additional loads from a roofed and screened enclosure.

Enclosing an Existing Covered Porch

Adding screens to an existing roofed porch may still require approval.

The review may consider:

• Whether the original porch was permitted
• Whether the foundation supports enclosure loads
• Guard and railing changes
• Door and window conditions
• Electrical work
• Pool-barrier implications
• Whether the porch will remain unconditioned

Replacing removable insect screens is different from constructing permanent screened walls, doors and framing.

Converting a Screened Porch Into a Sunroom

Replacing screens with windows can change the project into an enclosed addition.

Additional requirements may include:

• Insulation
• Energy-code compliance
• Heating and cooling
• Foundation verification
• Glazing safety
• Emergency escape and rescue openings
• Air sealing
• Electrical and mechanical permits

Our guide on site plans for home addition permits explains the additional property information that may apply.

Do You Need a Survey?

Not every screened porch permit requires a new boundary survey. An existing survey, house-location plan or recorded plat may provide a suitable base.

A new or updated survey may be needed when:

• The porch is close to a property line
• Property corners cannot be located
• The fence may not follow the legal boundary
• The lot is irregularly shaped
• An easement location is uncertain
• Certified elevations are required
• The property is in a floodplain
• The permitting authority specifically requests one

A drafted permit site plan is not a legal boundary survey and should not be represented as one.

See our guide on site plans versus surveys for more information.

Common Screened Porch Site Plan Mistakes

Permit applications can be delayed when the site plan is incomplete or inconsistent with the construction drawings.

Common mistakes include:

• Property boundaries are missing
• The proposed porch is not clearly labelled
• Porch dimensions are missing
• Setbacks are not shown
• Roof overhangs are ignored
• Roof coverage is calculated incorrectly
• The existing deck or patio is omitted
• Footing locations are not coordinated with the foundation plan
• Porch floor height is missing
• Stairs and landings are omitted
• The connection to the house is unclear
• Other existing structures are missing
• Lot coverage is not shown where required
• Easements and utilities are ignored
• Roof drainage is not addressed
• Ground slopes and retaining walls are omitted
• The pool barrier is not shown
• The drawing is not to scale
• There is no north arrow
• The site plan conflicts with the floor plan, roof plan or elevations

What Information Is Needed to Prepare the Site Plan?

Collect as much of the following information as possible:

• Property address
• Porch length and width
• Total porch area
• Roof dimensions and overhangs
• Porch floor height
• Attached or freestanding design
• Preferred porch location
• Distances to nearby property lines
• Stair and landing location
• Existing deck or patio information
• Foundation or footing design if available
• Photos of the property
• Rough sketch with measurements
• Existing survey or plot plan
• Recorded plat if available
• Architect, builder or manufacturer drawings
• Known easements
• Utility and drainage information
• Site levels or slope information
• Permit-review comments

Screened Porch Site Plan Checklist

Does a Site Plan Guarantee Permit Approval?

No. A clear site plan provides the property and location information needed for review, but approval also depends on zoning, structural design, building codes, soil conditions and the project scope.

The project may also require:

• Foundation and structural plans
• Building elevations and sections
• Licensed boundary survey
• Zoning approval
• Electrical or mechanical permits
• Stormwater or grading approval
• Floodplain or environmental review
• Historic-district approval
• Tree-removal approval
• Septic or health-department approval
• HOA or architectural-review approval

Need a Screened Porch Site Plan?

Site Plan Pros prepares clear residential site plans for homeowners, contractors, porch builders and permit applications.

Your screened porch site plan can show:

• Property boundaries
• Existing house and structures
• Proposed porch location and dimensions
• Boundary setbacks
• Roof coverage and overhangs
• Footings, stairs and landings
• Driveways and walkways
• Drainage and grading
• Easements and utilities
• Other important property details

You may also find our guides on deck permit site plans, home addition permit site plans, patio cover and pergola site plans and permit site plan checklists helpful.

Confirm the local permit, setback, footing, roof-coverage and structural requirements before ordering materials or starting construction.

Sources

1. City and County of Denver — Residential Decks, Porches, Patios, Pergolas and Carports
2. City of Portland — Residential Addition Permits and Plan Requirements
3. City of Portland — Fences, Decks and Outdoor Residential Projects
4. Fairfax County — Permits, Building and Construction
5. Fairfax County — Residential Addition and Alteration Permits
6. City of Portland — Building Permit Plans for Residential Projects
7. City of Charlotte — Residential Permit Plot Plan Instructions
8. City of Portland — Detailed Plans for Residential Decks and Covered Decks
9. Fairfax County — Soil and Footing Requirements for Minor Construction Projects
10. City of Charlotte — Individual Residential Lot Reviews