Accurate impervious cover calculations, comprehensive site dimensioning, detailed grading and drainage plans, compliant ePlan submissions, and the application of Dallas’s local zoning overlays are essential for successful residential permit approvals. Dallas adopts the 2021 International Residential Code (IRC), 2021 International Building Code (IBC), and the Dallas Development Code-especially Chapter 51A, with significant local amendments-affecting how these requirements are drafted and documented on site plan sheets. Every drawing package prepared for the Dallas Department of Sustainable Development (DSD) must reflect absolute fidelity to specification, code, and administrative process.

Precision Impervious Cover Calculation and Graphic Representation on Dallas Residential Site Plans

CAD-Based Area Extraction Workflow

Final impervious cover percentages are scrutinized in Dallas residential permit plan review, requiring a granular workflow in the CAD environment. Each impervious element-main structure, driveways, patios, walkways, AC pads, pool decks-is drafted on isolated CAD layers. For accuracy and auditability, polyline boundaries are created around each impervious surface using object snaps to property and construction lines; these are then grouped per distinct use.

The AREA command (AutoCAD) is used to calculate each surface’s square footage, recorded per element (for instance, 1,452 sf house footprint, 320 sf attached garage, 890 sf driveway). These values are then summed in CAD or in the calculation spreadsheet to show total impervious area. Dividing this sum by the surveyed lot area yields the impervious cover percentage, which is benchmarked against the maximums set out in Dallas Development Code Chapter 51A-4.803(d)(5).

Mandatory Tabular Data Display

Dallas mandates a prominent site data table on every site plan. In compliance with Dallas Development Code Chapter 51A-4.803(d)(5), this table includes:

  • Lot area (both in square feet and acres), as per survey or recorded plat
  • Building floor area (total and per use-residence, garage, accessory-sq ft)
  • Floor Area Ratio (FAR): total building floor area / lot area, carried to two decimals
  • Coverage percentages: both building coverage (sum of all building footprints) and impervious coverage (total impervious area divided by lot area), both as absolute sf and % values. For example:
    “Building coverage: 2,145 sf (28.6%); Impervious cover: 3,435 sf (45.8%)”
  • Parking: required and provided, with stall dimensions and count
  • Dallas zoning classification (e.g., R-7.5(A), R-5(A), SF-2, PD-xxx, etc.)

All values must be internally consistent-errors here are a common source of plan-review “Correction Required” redlines.

Required Graphic Symbology

Standardized visual communication is non-negotiable on Dallas site plans, and impervious cover must be instantly distinguishable. Best practices include:

  • Impervious surfaces: Solid hatching (usually dense diagonal crosshatch or solid fill) for driveways, roof footprints, patios, and walkways. Applies to both proposed and existing surfaces. Use distinct hatch fills for each surface type, e.g., one pattern for concrete, another for roof overlays.
  • Pervious surfaces: Dotted or open hatching, such as scattered dot or grassline, for lawn or planting areas. Never leave these open-city redlines often cite “Unclear pervious/impervious differentiation-revise legend.”
  • Contour lines: Continuous thin lines, labeled at minimum every 10', showing both existing and proposed grades. Elevation labels in feet, e.g., “543.7” at spot elevations.
  • Surface water flow: Flow arrows at all grade breaks, showing drainage direction (“Plan missing surface drainage direction arrows at rear yard-add and label.”)
  • North arrow and scale: Graphic scale bar and north arrow must always appear, usually lower right or upper right above the title block.

Common DSD Plan-Review Redlines

Application missteps nearly always result in DSD plan-review interruptions.

  • Misclassification: Failing to count walkways, pool aprons, or fire pit pads as impervious. Common redline: “All hardscape over 3' wide must be classified as impervious cover (51A-4.803(d)(5)).”
  • Calculation discrepancies: Table totals not matching hand-drawn or CAD-added areas. Corrective note: “Plan data and hatching area sums do not match. Revise CAD area extraction and recalculate.”
  • Omitted elements: “Existing sidewalk not included in impervious cover-add to calculations.”
  • Setback non-compliance: “Driveway encroaches 2.5' into required 5' side yard setback-relocate or reduce width.”

Redlines almost always ask for the supporting calculations as a PDF exhibit or annotated screenshot from CAD, under the plan data table.

Standard Sheet Call-Outs and Material Specs

Site plans require:

  • Title block (project name, address, preparer's info, date, sheet number - typically lower right or right margin, per DSD guidance)
  • Legend (explaining all hatch patterns, with sample swatch and label, e.g., “Solid fill: impervious-concrete”)
  • Detail or note call-outs: bubbles/call-outs referencing “See C-2 for driveway section” or similar
  • General notes, e.g., “All impervious paved areas shall be of 4” min. 3,000 psi concrete over compacted subgrade. Provide surface drainage slope ≥2% away from structure (IRC R401.3).”

The Dallas Development Code does not specify impervious surface materials but references IBC/IRC for construction minimums. For example, driveways and walkways must be a minimum 4” thick, 3,000 psi concrete per IRC R309. Patios, per IRC R507, to use pressure-treated framing where less than 8” above grade.

For code support: Dallas Development Code Chapter 51A-4.803(d)(5)

Comprehensive Site Dimensioning and Setback Compliance for Dallas Residential Permits

Granular Dimensioning of All Site Elements

DSD expects comprehensive dimensioning encompassing every planimetric edge:

  • Building outline: Show wall face to property lines at all corners, with distances to two decimals (“Residence: 27.35’ min. front setback; 5.12’ min. side (west); 5.25’ min. side (east); 23.96’ rear.”)
  • Paving: Dimension from edge of driveway/patio/walkway to nearest property line and house face; width and length of each
  • Accessory structures: “8’x12’ storage shed, 5.02’ from rear lot line, 7.86’ from east lot line.”

Include all projections (eaves, bay windows). Dallas redlines often cite “Missing dimension to eave projection from side/rear yard-add.”

Accurate Representation of Setbacks Per Zoning District

Dallas uses specific zoning districts for single-family residential: R-7.5(A), R-5(A), SF-2(A), and more. Each district sets specific setback, lot coverage, and building height restrictions. For example, per R-7.5(A):

  • Front yard: 25’ minimum from ROW
  • Side yard: 5’ minimum each side
  • Rear yard: 5’ minimum
  • Max. lot coverage: 45%
  • Height: 36’ max. (measured per 51A-4.408, from average front grade)

These must be graphically depicted-drawn setback lines, dimension string annotations, and labeled zones. On the drawings:
“Dashed line denotes 25’ required front yard setback (per 51A-4.401); shaded zone is min. 5’ side and rear yard setbacks.”

Utility/Drainage Easements and Critical Root Zones

All site plans must highlight utility and drainage easements-recorded on plat, title, or survey-typically in dashed lines with widths and recording info labeled:

  • “10’ U.E. (Vol. 95012, Pg. 1647 DRCT, 2010)”
  • “15’ D.E. (Vol. 78075, Pg. 2121 DRCT, 1992). NO BUILDINGS ALLOWED.”

Redlines for missing or erroneous easement annotation are frequent: “Show all easements per plat/record-provide volume and page references.”

Per the Dallas Tree Ordinance (Article X, Chapter 51A), trees ≥6” at 4.5’ above grade are subject to Critical Root Zone (CRZ) delineation-a circle with a radius in feet equal to the trunk diameter in inches. For example, a 15” oak requires a 15’ CRZ. Every CRZ must be geolocated and graphically shown as “Shaded circle, 15’ radius from trunk center-protected CRZ. No construction within zone absent tree mitigation per Article X.”

Typical Plan-Review Comments on Dimensions and Encroachments

  • “Provide setbacks from all projections-dimension from eave/bay to property line.”
  • “Rear patio encroaches into required 5’ setback (51A-4.401). Revise layout.”
  • “Accessory structure sited within 10’ utility easement-relocate or provide recorded release.”
  • “Site plan omits CRZ for 18” pecan tree-add and label.”

Dimensioning errors can delay approvals by weeks. The plan package must contain every dimensioned distance to fixed property lines, setbacks, easements, and protected areas, with annotation bubbles or “keynote” tags referencing detail sheets or code references.

Drawing-Sheet Call-Outs, Details, and Specs

  • Legend with all line types - dashed for easements, shaded for setbacks, solid for CRZ contours
  • General notes, e.g., “No structures or grading within easements without written utility release,” “Protected CRZ per Article X; tree protection fencing to be installed at dripline.”
  • Specific dimensions called out on each feature, measured to two decimals
  • Fire ratings and material specs (where applicable), per IBC/IRC and local amendments

All notes should be linked by call-out bubbles or key numbering-reviewers expect to see “See Note 3 for CRZ fencing detail.”

Reference: Dallas Zoning Districts

Detailed Grading, Drainage, and Stormwater BMPs on Dallas Residential Site Plans

Topography, Spot Elevations, and Contours

Dallas requires both existing and proposed grades to be shown. Site plans must include:

  • Contours: 1’ or 2’ interval (max 10’, though best practice is 2’ or less), labeled throughout, with clear differentiation between existing (dashed) and proposed (solid) topography
  • Spot elevations: Key locations-corners of structure, driveways, high/low points, flow lines-with call-out text, e.g., “FF=549.35”, “Garage slab=548.72”
  • Surface water flow arrows: Labeled and oriented visually; e.g., “Drainage to street,” “Drainage to rear swale-see detail 5/C-3.”

Commonly flagged by DSD: “Existing vs. proposed contours not differentiated-revise line type or color.”

Surface Drainage Elements and Pipe Routing

Every discharge path must be explicit. Swales, catch basins, yard drains, and storm pipes are detailed using standards from the Dallas Drainage Design Manual:

  • Swales: Dimensioned width, side slopes (typically min. 2:1), flowline elevations at 10’ increments
  • Inlets/catch basins: Labeled, with size (“12x12 yard drain inlet”), invert elevation call-out (“Inv.=547.1”)
  • Storm pipes: Centerline, diameter, material (“6” HDPE @ 0.8% min. slope”), start/finish invert elevations referenced to city datum or benchmark

Call-outs reference city standard details: “Install yard drain per City of Dallas Std. Detail D-9; pipe slope min. 1% per Drainage Manual.”

Finished Floor Elevation (FFE) and Floodplain Documentation

Site plans abutting or within the Special Flood Hazard Area (SFHA, per DFIRM) require rigorous FFE documentation. Dallas ordinance and FEMA standards require FFE at least 2’ above BFE (base flood elevation). Report FFE call-outs at the primary entry and document BFE per FEMA FIRM panel:

  • Call-out: “Proposed FFE: 555.10’ NAVD88 (BFE=553.2’ NAVD88, per FIRM Panel 48113C0430K)”

Omitted FFE/BFE data is a plan-review bottleneck: “Provide DFIRM panel number and datum reference-indicate BFE and FFE on plans.”

Common Redlines and Plan-Review Comments

  • “Site plan lacks spot elevations at corners-add and label.”
  • “Swale side slopes not dimensioned-provide width/depth/side slope per City Detail D-7.”
  • “Drainage pipe inverts not shown-add inverts and material spec.”
  • “FFE not documented vs. floodplain-update sheet A1.”

To clear DSD review, every drainage component must have detailing and dimensioning, all contouring and spot grades labeled, and all FFE/BFE relationships expressed visually and tabularly.

Drawing-Sheet Call-Outs and Material Specs

  • Legend: All contour lines, flow arrows, swale/ditch hatches, pipe materials
  • Drainage structure details: “Refer to Detail D-9 for yard inlet; 12x12 grate, 0.5’ sump, frame and cover per City spec.”
  • Pipe spec: “6” HDPE, min. slope 0.8%, Class 120 per DWU Manual”
  • Finished floor elevation boxed call-out at front door location

Reference: Dallas Drainage Design Manual

DSD ePlan Submission Protocol and Plan-Review Redline Resolution

Required Site Plan Content Checklist

  • Property boundaries with bearings/distances (from survey); lot area in sf/acres
  • All setback lines, drawn and labeled (front/side/rear as required)
  • Existing/proposed structures: footprints, roof overhangs, decks, accessory buildings
  • Lot coverage, impervious cover, and FAR tables (per Section 51A-4.803)
  • Parking and drive access; dimensions and compliance (stall width/depth, required vs. provided count)
  • Landscape areas and tree protection (CRZ)
  • Utilities and easements, with recording information and widths
  • Topographical info (contours, FFE, flow arrows, BFE if applicable)
  • Legend, north arrow, scale bar, title block (project/sheet/preparer/date)

Each sheet must display a “Clear area, 2”x3”,” in upper-right for DSD’s electronic approval stamp.

PDF Preparation and ProjectDox Protocols

Every drawing sheet is uploaded as a single PDF per sheet-multi-sheet PDFs are rejected. PDF file names follow DSD naming: “C-1 Site Plan.pdf”, “A-1 Floor Plan.pdf”, etc. Ensure landscape orientation, purged of unnecessary layers, with all fonts embedded and not outlined. PDFs must be fully searchable with bookmarks for sheets where applicable. Leave batch stamp area blank. DSD Best Practices offers precise formatting requirements; violations receive instant “Resubmit” requests-e.g., “PDF contains multiple sheets in file-resubmit as individual PDFs,” “Approval stamp area not clear.”

Resolving DSD Plan-Review Comments

  • “Cloud” all revisions on the affected sheet(s), with revision #/date in the revision block.
  • For each reviewer comment, write concise “Response” in ProjectDox comments (“See A-1, revision 3; added required driveway dimension to side property line as requested”).
  • Never alter file names; always overwrite existing file in ProjectDox to preserve automated version history.
  • Administrative comments are typically: “Documents missing signature,” “Site plan incomplete-add legend,” or “Project address not on every sheet.” Respond promptly within ProjectDox; delayed responses pause review “clock.”

Drawing-Sheet Conventions and Code-Specific Specs

  • Title block is right-margin or lower right; project info, sheet #, preparer, date
  • Revision block for date/description of each change (preferably upper right or immediately above title block)
  • All scale bars graphic and labeled (1”=20’-0”) on each site sheet
  • Setbacks and lot lines called out with bold dashed lines, dimensions, and code section reference
  • Material specs: “All site and foundation work per 2021 IRC with Dallas amendments. Concrete walkways 4” min., 3,000 psi,” etc.

Consult 2021 Dallas Amendments to IBC/IRC for local material specs. DSD expects all code references cited-e.g., “Side yard setback per 51A-4.401; FFE per 51A-5.105.”

Applying Dallas Zoning Overlays and Code Amendments to IRC/IBC on Residential Site Plans

Interpreting and Depicting Local Amendments

Section 51A-4.400 and 51A-4.602 of the Dallas Development Code contain critical overlays and amendments governing accessory structures, fence heights, and sight-visibility triangles, frequently overriding IRC/IBC minimums.

  • Accessory structures: Rear yard setback for sheds and detached garages is at least 5’ per 51A-4.401(a)(3), superseding IRC’s 3’ min. for accessory “tool sheds” (see Section R302). Plan annotation:
    “Accessory building located >5’ from rear lot line per 51A-4.401(a)(3).”
  • Fence heights: “Fences in required front yard shall not exceed 4’ in height (Section 51A-4.602(a)), except by specific variance.” Fences in rear/side may be 8’ max.; plan must show elevations and call-outs:
    “Proposed fence: 6’ wood, rear yard, compliant with 51A-4.602(a).”
  • Sight-visibility triangles: Any feature obstructing visibility in these defined triangles (20’ x 20’ at street corner, 10’ x 20’ at driveways-51A-4.602(a)(2)) is not permitted above 2.5’ high. Plan detail:
    “Dashed triangles at driveways, labeled ‘Sight-visibility triangle per 51A-4.602(a)(2); no obstructions above 30” high.’”

Mandatory Notes and Drawing Citations

Reviewers expect code-cited notes on all plans, both on overall site sheets and in details:

  • “Note: All accessory structures comply with setback requirements as per Dallas Development Code Section 51A-4.400.”
  • “Note: Fence heights per Section 51A-4.602; see site plan for height zones.”
  • “Note: Sight-visibility triangles protected per Section 51A-4.602. No fences, walls, or landscaping over 30” in this area.”

Failure to cite sections is a common redline: “Missing code references for setback and fence height-add Dallas City Code section call-outs to site and fence details.”

Overlay Districts: Conservation Districts, PDs, and Common Errors

Overlay zones such as Conservation Districts (CDs) and Planned Development (PD) districts impose additional or superseding controls over base zoning. Some CDs mandate specific facade proportions, porch dimensions, or garage placements. PDs may create entirely bespoke setbacks, height limits, and architectural style constraints.

Frequent drawing errors:

  • Using base zoning setbacks within overlays-“Plan applies R-7.5(A) rear setback, but site is in CD #16 which requires 15’ rear. Revise site plan setback lines and dimension labels.”
  • Omitting required overlays-“No Conservation District regulation reference-add note and refer to CD overlay sheet.”
  • Failing to include overlay-specific submission: “CD district requires Certificate of Appropriateness-provide with resubmittal.”

Every plan must document all overlay requirements, with explicit notes and drawing conventions. If in a CD or PD, provide a summary chart or bubble call-outs cross-referencing both base and overlay requirements: “Setbacks and fence heights per CD #3 (Ord. 22314), Section 7(a).”

Drawing-Sheet Call-Outs and Detail Conventions

  • Setback lines: bold dashed lines on site sheets, labeled with “5’ rear setback per 51A-4.401 or CD overlay”
  • Fence elevations: exterior elevation/section drawing, height dimension and note (“8’ max. per 51A-4.602(a)”)
  • Sight-visibility triangle: dashed lines with diagonal “T” hatching, note restricting height
  • Accessory structure location: call-out with explicit setback, note code section

For detailed overlay requirements, consult Dallas Site Plan Requirements Guide and CD/PD district ordinances.

Conclusion

Achieving approval for Dallas residential site plans requires rigorously accurate impervious cover tabulation, unambiguous dimensioning, adherence to drainage and grading standards, meticulous documentation of all overlays and code amendments, and strict alignment with DSD’s digital submission protocols. The city’s plan reviewers rely on both the accuracy of the site’s data and the clarity of its graphical communication-errors delay approvals, while comprehensive, standards-driven drawings streamline the process. Kingsway Drafting & Design delivers compliance-driven drafting that meets or exceeds the expectations of Dallas permit authorities and builders.