There are 2 distinct working environments in which you can create objects in an M/E/P drawing:
- Model Space. This space is a limitless, 3D drawing area. In model space, you draw, view, and modify your building system designs.
- Paper Space. This space is a 2D sheet layout environment. In paper space, create specific views of your designs, add annotation, and create plotting sheets.
In AutoCAD MEP 2025 toolset, these spaces are accessible on 2 or more tabs at the bottom of the drawing area: the Model tab, the Work tab, and one or more sheet tabs. They are turned off by default. Enter LAYOUTTAB on the command prompt to enable them.
- Model Tab. This tab is available on both the model and sheet templates. It can be set to only TILEMODE 1, which means you can divide the drawing area into multiple viewports (a process called tiling). Each tiled viewport can display a different view of the model. For example, one viewport might display a plan view, and another might display a side view. The same display configuration must be used in all tiled viewports, and you cannot use floating viewports or freeze different layers in different tiled viewports.
- Work Tab. Available on the model templates, this tab enables you to work with your design in both plan and 3D at the same time. The tab contains 2 viewports, each of which is assigned a default display configuration. One viewport is assigned a Top (plan) view direction for working with schematic, single-line, double-line, or reflected ceiling plans. The other viewport is assigned an isometric view direction for creating isometric drawings and performing other tasks better suited to an isometric view. You can create a copy to add a second work tab, or delete the work tab if it is not needed for a particular project.
- Sheet Tabs. These tabs (also called layout tabs) are available on the sheet templates. Use the tabs to configure a layout of your drawing for plotting or printing. The sheet tabs include a border and title block, which you can modify and apply to your projects or replace with a custom border and title block.
There are advantages to working on tabs other than the Model tab. On other tabs, you can assign different display configurations to different viewports, freeze different layers in different viewports, and use floating viewports.
The default templates provided with the software each include one or more layout tabs for designing and plotting building systems. The tabs are configured to promote efficient and accurate designs.