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 Public Buildings Service

PBS CAD STANDARDS

Introduction: The intended audience for the PBS CAD Standards is architects/engineers (A/Es) (or other

contractors) preparing CAD deliverables for GSA, along with GSA staff requesting and reviewing CAD

deliverables. Direct any questions to the GSA Contracting Officer (CO) or Contracting Officer’s Representative 

(COR). Paragraph numbers below are for ease of reference. The PBS CAD Standards and a list of PBS CAD

managers are available at www.gsa.gov/cad or www.gsa.gov/cifm. It is the A/E’s responsibility to obtain its 

own copy of the United States National CAD Standard® (NCS) www.nationalcadstandard.org. 

1. GSA has adopted the NCS. A/Es preparing CAD deliverables for GSA, including design and construction and

spatial data management (SDM) drawings, must comply with NCS Version 6. The purpose of the PBS CAD

Standards is to set the following additional requirements. GSA Regions or other programs may have further

requirements.

2. GSA will not waive NCS or PBS CAD Standards requirements under any circumstances, including when A/Es

use building information modeling (BIM). CAD drawings exported from the building information model must

comply with NCS and PBS CAD Standards requirements.

3. A/Es must submit CAD drawings in DWG file format. The DWG files must meet GSA’s “no error”

requirement, which means that GSA must be able to open the file in its current version of AutoCAD without

being prompted with any error messages. Some examples of error messages include font not found, xrefs

not found, image xref resolution errors, and proxy object errors. The “no error” requirement does not mean

files must be authored in “out of the box” AutoCAD only. A/Es may use the following exceptions with

advance approval and confirmation in writing from the GSA CO or COTR:

• A/Es may author files using all the advanced features (including the 3-D features) of Autodesk AutoCAD

Architecture and AutoCAD MEP.

• A/Es may use an AutoCAD third-party add-on, if the A/E provides GSA with a fully supported and free

object enabler.

• A/Es may use other vendor CAD applications as long as NCS and PBS CAD Standards requirements are

met.

• A/Es may choose to use more recent software versions than GSA is using, but the A/E must provide the

more recent version files and a set of files saved as a version usable by GSA.

4. The A/E must include the following items with each drawing submission:

• A signed cover letter on A/E firm letterhead (in Adobe PDF file format) stating:
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To the best of my knowledge, the DWG files submitted meet GSA’s “no error” requirement when opened. And, 

without the need for any add-on software, GSA can view and manipulate all drawing entities and plot drawings from 

the DWG files submitted that accurately reproduce the PDF files and paper drawings submitted. Further, the 

contents of the DWG files represent all drawing entities, plot drawings, and configuration settings necessary to 

accurately reproduce the PDF files and paper drawings. 

• The completed and signed NCS Statement of Substantial Conformance form (in PDF file format) (see NCS

Appendix A for a blank copy of the form).

• One self-contained file representing each single drawing sheet, with reference files inserted. If using

AutoCAD, the appropriate command is Bind using the Insert selection. Do not explode result. Bound

layers must maintain NCS layer names.

• All project files (such as detail, model, sheet, and reference files) used to produce the paper drawing

sheets. A/Es must make certain to include all base drawings, custom fonts, line types, pen tables, etc.,

used to produce the drawing submission. AutoCAD has an express tool command called etransmit that

can create a package of all reference files.

• List of files and reference relationships (in a Microsoft ReadMe.doc or ReadMe.xls file).

• One full-size set of the drawing sheets (as PDF files) capable of producing a paper drawing set.

5. The A/E is responsible for ensuring that all submissions by any subcontractors comply with the “no error”

requirement and other NCS and PBS CAD Standards requirements. Before the start of the project design

phase, the A/E must submit sample electronic files to GSA to verify that its software (and that of its

subcontractors) complies. Any CAD drawing submission that does not substantially comply will be rejected

and appropriate contract action, including withholding of payment, noting on contractor past performance

reports, and/or other remedies, may be taken by GSA.

6. Electronic files and media submitted to GSA must not contain computer viruses. The A/E must label media

with the contract/order number, project title, project number, submission stage, submission date, and

security imprint at a minimum (see Item 8 below for more information). The A/E must submit all files on

GSA-readable CDs or DVDs, which may not contain compressed (ZIP) or self-extracting (EXE) files. GSA must

be able to read all submitted media and without being prompted with error messages.

7. All digital files, associated data, and other products generated under any GSA design and construction

contract become the property of the Government.

8. The A/E must comply with GSA Order PBS 3490.1A Document Security for Sensitive but Unclassified Building

Information, dated June 1, 2009. The imprint specified in the order is required on the cover sheet and each

drawing sheet, stating the required secure handling of federal building information. The A/E must include

the imprint on the disc label as well.

9. The A/E must name model files using the format below.

A-AA-UU-OOOOO.EXT or

AAAA-UU-OOOOO.EXT

Discipline designator (Level 1 or 2)-model file type-GSA floor 

number code-optional suffix for A/E use.file extension

10. The A/E must name sheet file names using the format below.
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A-NNN-UU-OOOOO.EXT or

AANNN-UU-OOOOO.EXT

Sheet type ordesignator sheet sequence number-GSA floor 

number code-optional suffix for A/E use.file extension

11. The A/E must name any other project files delivered to GSA using the format below.

NN-NNNNNN-UU-OOOOO.EXT OmniClass table number-MasterFormat item number-GSA floor 

number code-optional suffix for A/E use.file extension

NN-ANNNN-UU-OOOOO.EXT OmniClass table number-UniFormat item number-GSA floor 

number code-optional suffix for A/E use.file extension

12. GSA does not use the NCS suggestion for naming detail files and schedule files. The A/E should use the

format above in Item 11.

13. The A/E does not have to submit its library files to GSA, such as blocks; only those files from its library used

on the GSA project need to be submitted.

14. GSA has added the following discipline designators below to those already in the NCS. GSA discourages the

use of the discipline designator “ET” for electrical telecommunications. The A/E must use “T-” or its own T

Level 2 designator instead.

Roof and roofing Public spaces, green roofs, antennas, etc. AR

Skin or envelope Energy performance determinant elements AE

Walls and partitions Nonload-bearing space defining objects AW

Space assignment GSA BIM Guide Series 02 – BIM Guide for Spatial Program 

validation, rent bill management

AS

Doors, frames, and hardware AD

Transportation systems AT

15. GSA floor number codes must be only two characters. Most floors will be designated 01 through 99.

R1, R2, R3, ...R9 Roof level, higher number is higher up

P1, P2, P3, ...P9 Penthouse, not a full floor plate

M1, M2, M3, ...M9 Mezzanine

01 (or GF), 02, 03, ...99 Floor 1 (or ground floor), then floors 2 to 99

L1, L2, L3, ...L9 Lower level, a floor partially below ground, higher number is further down

B1, B2, B3, ...B9 Basement floor fully underground, higher number is further down

SB Subbasement, not full building footprint

SP Site plan

LT Loft, a level with two or less exterior walls

K1, K2, K3, ...K9 Parking, higher number is higher up

NN More than one floor, used for floor stacking in large building model files, 

exterior elevations, etc.

XX No floors, used for G series, most details

16. GSA requires that the A/E use one additional model file type to manage antennas and green roofs.

RO Roof plan

17. The A/E must use the sheet type designators below.

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0 General

1 Plans

2 Elevations, no cutting plane

3 Sections with cutting plane

4 Large-scale views

5 Details that are to scale

6 Schedules, diagrams, and details that are not to scale

7 3-D representations to scale such as axonometric drawings

8 Other, such as photographs, scanned images, animation stills, multimedia, etc. Also, not

generated from the building information model.

9 3-D representations not to scale. Also, generated from the building information model.

18. Although not required to be used, all file names may have an Optional Suffix (-OOOOO) (five characters

shown for example only) for A/E use. However, the Optional Suffix:

• Must start with a single dash.

• Must not exceed 25 characters in length.

• Must not include spaces, periods, or underscores.

• Must not include glyph characters from Asian and Cyrillic alphabets.

19. Model files must include a model file information block with, at a minimum, the GSA project title, building

number, project number, and contract number. The sheet file title block must contain the following

information at a minimum and if applicable:

• GSA contract/order number, project title, and project number

• GSA building name, building number, and street address

• Submission date, stage, and percent (for example, 100 percent construction documents)

• A/E firm name(s)

• Certifications (signatures and seals) (DWGS do not need to display)

• Key plan and North arrow

• Graphic scale

• Drawing date and revision dates

• Drawing title (type of drawing and contents) and drawing number

• Drawing scale (plot scale of sheet file) and sheet size

20. The A/E must comply with the following requirements:

• Draw models life size using architectural units. One drawing unit equals 1 millimeter or 1 inch.

• Use the Metric Design Guide (PBS PQ-260) for projects subject to the Facilities Standards for the Public

Buildings Service (P100).

• Use sheet files to create views to scale of the model for plotting as a sheet.

• Do not use a single file for multiple sheets. Use one file per sheet. This applies to DWG and PDF file

formats.
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• Accurately represent actual building dimensions within 1 inch of exterior and half an inch of interior field

measured conditions.

• Use precision input and object snaps.

• Ensure that line endpoints meet exactly, tangents intersect at a single point, and vertical lines are at

exactly 90°.

• Create entities within blocks on Layer 0 and avoid use of nested blocks.

• Define objects’ layers and line types by layer unless inside a complex block definition.

• Put hatch patterns on their own layer.

• Use PATT to modify any major or minor group in the layer list. Do not explode.

• Limit use of ANNO as a minor group field.

• Include any A/E-defined hatch patterns, line types, and colors with drawing submission.

• Ensure that plotted text does not appear smaller than one-eighth of an inch height (one-sixteenth of an

inch on half-size drawings).

• Purge drawings of unreferenced blocks, layers, and line types. If using AutoCAD, audit as well.

• Delete objects outside drawing limits and zoom to drawing extents.

• All external reference files must use a common insertion point.

21. GSA may provide the A/E with existing CAD drawings for convenience. However, these drawings must be

used as a base reference only. Unless otherwise specified by the contract documents, the A/E is responsible

for field verification of existing conditions and ensuring that all electronic deliverables are accurate and

comply with NCS and PBS CAD Standards requirements.

22. Construction documents must be signed and sealed by the responsible design professional. To meet this

requirement, the A/E must submit a full set of 100 percent final construction documents as PDF files. Each

drawing sheet, as well as the cover pages of the specifications and any engineering calculations, must

display the appropriate signatures and seals.