Attributes - Attributes may be used to store data in the drawing. Do not use attributes to store large amounts of data (greater than 10% of drawing size) or types of data that are better stored in external databases. NIH requires the use of an attributed title block and a model file attributed block to store descriptive data about the drawings, see title blocks.
Blocks - Any graphic entity that occurs repeatedly in drawings should be made into a block. Attributes contained within a block should pertain to the current project. Insertion points for each block shall be consistent with its placement in the drawing. Use logical insertion points such as the center of a circle, bottom left corner of an object, etc. Keep names simple and descriptive. Purge all unused blocks from the drawing. Nested blocks are permitted but should be avoided whenever possible. If nested blocks are used, they must be documented on the Project and Drawing Documentation form (see Section 3 Deliverable Requirements). Draw objects used to create blocks on layer 0 so the block inherits the properties of the layer on which it is inserted. Do not insert blocks on layer 0 (zero). When submitting drawings no objects will be on layer 0 (zero) unless otherwise specified.
Dimensioning - All dimensions shall update automatically when the distance they are measuring changes (associated dimensioning). Refer to the NIH Design and Policy Guidelines for additional standards.
Drawing limits - Do not set the limits any larger than necessary to accommodate the drawing. No entities shall be located outside the drawing limits.
Drawing origin - Organize drawings in model space so that the lower left intersection of the outermost column lines that remain constant on most floors is placed at 0,0,0. In order to ensure proper insertion of xrefs and the stacking of floor plans, the origin point for an entire building must be consistent between model files. Once the origin is established, it cannot be changed. For sheet files, place the lower left corner of the sheet at 0,0,0.
Graphic standards - Drawing standards and symbology shall be in accordance with the AIA Architectural Graphic Standards. The U.S. National CAD Standard is also a good reference for drawing symbols, details, and guidelines.
Hatching - Do not use polylines with increased width for poché or hatching. All hatching shall be associative.
Key Plan - G-SITE is the layer on which the key site plan should be drawn.
Layers - Use the NIH Autodesk Architectural Desktop Layer.
Layer colors – All entities shall be assigned color by layer.
Line types - Contour lines, dashed lines, and other fonted lines shall be made of one continuous line segment, not a series of separate line segments. If line types other than standard Autodesk® Architectural Desktop line types are used the *.LIN file must be provided with the submission. Section 5.0 Files for Download includes a *.LIN file for use. Use of toned or pochéd lines are acceptable for distinguishing between various types of work, such as new from existing, phase 1 from phase 2, or background floor plans. Curved entities such as circles, arcs, and ellipses shall be created of one continuous line segment, the exception being entities that have to be physically constructed in a segmented fashion. These may be segmented to represent the joints in the actual construction.
Line weights – See sample line weight in Part 3.
Scale - Create drawing entities at full size. For example, a 30 meter wall will be drawn to meters and a 1 meter column will be drawn to 1 meter. Drawings considered schematic in nature can be drawn to any scale. Some examples of schematic drawings are schedules, riser diagrams, schematic diagrams, and single line diagrams.
Plan drawings - Create a separate sheet file for each drawing. Use sheet files to combine floor plans with non-plan information or multiple elevations. Do not combine several drawings such as elevations, sections, and details in one model file. When a floor plan is too large to fit on a single sheet at the desired scale use viewports in separate sheet files to show portions of the floor. DO NOT create individual model files for portions of a floor.
Title Blocks - NIH requires the use of a standardized, attributed title block for each sheet file. NIH also requires a standardized, attributed block in all model files. Templates, blocks, and instructions are listed in Section 5.0 Files for Download and are available at http://qualtrax.od.nih.gov/.
Text and fonts - Use only standard Autodesk Architectural Desktop or approved True Type fonts. The text syles.doc contains a list of acceptable fonts. The minimum plotted text size for all full size drawings shall be 2.5 mm. For clarity and presentation purposes it may be necessary to use other text sizes.
Units - Metric units shall be the standard system of measurement for new facilities unless otherwise specified. Ceiling grids shall be designed per metric standards, and metric size light fixtures shall be specified. Imperial units may be used for projects in existing buildings when existing drawings are Imperial. Project scope of work will specify use of Imperial or metric units. Base units for metric shall be millimeters for imperial use inches. For projects in metric system, all dimensions and distances shall be exact multiples of ten(10) millimeters.
Xrefs - Autodesk Architectural Desktop term for external reference. Xrefs help to organize drawing information, enhance coordination, and minimize redundant data. The xref path shall not include drives or directory designations and the xref is placed on layer G-ANNO-REFR. Document the relationship between drawing file and xref on the project documentation report and deliverables matrix. See Section 4.4 Project Documentation.
