Introduction:

In Revit, you can enhance the accuracy of your performance analysis by using Revit spaces, rather than Revit rooms, to export your energy model.

When you export your model using Revit rooms, a single set of assumptions based on the building type is applied to all of the rooms in the building. You can use Revit spaces to precisely describe the type or use, the occupancy schedule, and the energy use profile of each individual space in the model.

Creating and using spaces gives you a more accurate model of the occupant, heating, and cooling loads, as well as the power usage for the building.

Note: In Revit, rooms and spaces are not required for energy analysis. This is an advanced exercise and if you are not familiar with spaces and associated definitions, it will be useful to review this information here

 

This video shows the workflow for creating spaces in Revit.

Workflow Steps:

Open a Project

• Open the Building Model – Simple L Building – With Rooms Revit model.

Review the Export Category in the Energy Settings

• Go to the Analyze tab and open the Energy Settings.
• Open the Advanced Energy Settings, for Other Options, by clicking Edit.
• In the Advanced Energy Settings dialog, verify the Export Category in the Room/Space Data section.

Note that by default the Export Category is set to export rooms.

• Click OK twice to close the Energy Settings dialog.

Generate Insight for the Room Based Model

• Click the Analyze tab and click Generate.

Open the Space tool

• Open a floor plan view, for example, Level 1.

Note the room tags indicating that Revit rooms have been created in each of the enclosed spaces.

• Open the View tab and open the Visibility/Graphics tool, then switch to the Annotation Categories tab and uncheck the Room Tags to hide them.
• Click the Analyze tab and open the Space tool from the Spaces and Zones panel.

Add a Space Tag if Needed

• If prompted that no space tags are loaded in the project, click Yes to load one now.
• Navigate to the Annotations/Mechanical folder in your Revit library.  
• Select Space Tag, then click Open.

Place Spaces on One Level of the Model

• In the Option Bar or Properties palette, specify the parameters for the spaces that will be created such as the Upper Limit and the Offset.

A good practice is to set the offset to match your floor-to-floor height – for this model, 15 feet.

You can modify these parameters at a later time by selecting a space with the Modify tool, then editing these constraints in the Properties palette.

• Hover the cursor over an enclosed region in the drawing area, then click to place a space.
• Double click on the word Space in the space tag, then enter a name that will make it easy to identify the space.
• Repeat these steps for all of the enclosed regions on Level 1. 

To place spaces in the semi-bounded or unbounded area, you can use the Space Separator on the Space & Zones panel from the Analyze tab to create space separation lines to separate one area into many areas where a wall between areas is not desired or not possible. The space separation lines create areas that become full-bounded.

Place Spaces on Other Levels of the Model

• Open another floor plan view, for example, Level 2.
• Turn off the Visibility Graphics of the Room tags.
• Open the Analyze tab and open the Space tool.
• Again, specify the parameters for the spaces that will be created such as the Upper Limit and the Offset in the Options bar.
• Rather than placing spaces individually, click the Place Spaces Automatically button in the Modify | Place Space tab.
• Change the names of the spaces on this level.
• Repeat these steps for each of the levels.

Create a Schedule Showing All of the Spaces

• After all of the spaces have been created, create a new Schedule displaying all the spaces to easily edit their properties.
  • Open the View tab and open the Schedules pull-down menu, then choose Schedule/Quantities.
  • Select Spaces as the category to Schedule, then click OK.
  • Add these parameters to the Schedule fields.
    • Name
    • Space Type
    • Area
    • Number of People
    • Condition Type
  • Click OK to create the Schedule view.

Edit the Space Type for Each Space in the Schedule

• Open the Space Schedule view.
• Click the action button at the right end of the Space Type cell in each row of the Schedule.
• Select the Space Type that most accurately reflects the use of the space.

Note that as you change Space Types, the assumptions about the Occupancy Load and Schedule, the Lighting Load and Schedule, and the Power Load and Schedule for that space are applied to that space.

• Click OK to close the Space Type Settings dialog.
• Repeat these steps for each of the spaces in the Schedule.

Set the Export Category in the Energy Settings to Use Spaces

• Open the Advanced Energy Settings, for Other Options, by clicking Edit.
• In the Advance Energy Settings dialog, for Export Category, select Spaces from drop-down list of the Room/Spaces section.  
• Click OK twice to apply Energy Settings.

Save this Model Using a New Name

• Click the Revit application icon
• Select Save As to save the project as Building Model -- Simple L Building – With Spaces

Generate Insight for the Spaces Based Model and Access Results

• Click the Analyze tab and click Generate.
• Click Optimize to access the results.

Set the Baseline Assumptions and Save as a Scenario

• Set a range or value for the following Factors:
  • Operating Schedule: 12/6
  • Lighting Efficiency: 0.7 – 0.3 W/sf
  • Plug Loads Efficiency: 0.6 W/sf
• Select the Add Scenario button at the top right of the model viewer.
• Click the action button (the three dots to the right of the Untitled Scenario name), then choose Rename from the pop-up menu to change the name of this scenario.
• Set the name of this scenario to Baseline Scenario.

Create a New Insight to Compare the Space Based Versus Room Based Models

• Click Back to Insight and click Insights.
• Click Create Insight and select the submitted room based and space based models for comparison, then click Done.
• Click the action buttons (three dots) to the right side of the tile and choose Rename from the pop-up menu to change the name of the Insight. Set the name of this Insight to Spaces vs Rooms.
• Open the Insight by selecting the tile.

Use Scenarios to Apply Shared Assumptions within an Insight

• Select Back to Insight at the top left of the Model Viewer.
• In the Model Comparison dashboard, select Baseline from the Scenarios drop-down menu to apply the same assumptions to all the energy models in this Insight.

When you create a new Insight, the preferences may default back to Metric and Annual Cost. Be sure to reset the preferences to match the way you are viewing and comparing the data.

Note that improving the accuracy of your model by using spaces will not necessarily reduce the EUI mean. Even if the EUI mean is higher when computed with spaces than when computed with rooms, it is important to keep in mind that is a more accurate reflection of how the building will be used and a better prediction of true building performance.

 

Exercise:

Follow the steps outlined below:

1. Open the E1c_Rooms model in Revit
2. Open the Location tool and set Project Location
   • Change Project Address to Minneapolis, MN
   • Select Weather Station 32579
3. For the first energy simulation, run energy analysis using Rooms
   • Set the Energy settings to the following:
     • Mode: Use Conceptual Masses and Building Element
     • Building Type: Retail
     • Make sure to select Rooms as the exporting category
   • Generate Insight
4. For the second energy simulation, run energy analysis using Spaces
   • Save the project as E1c_Spaces
   • Access Energy Settings
     • Make sure to select Spaces as the exporting category
   • Generate Insight
5. Go to Insight.
6. Create an Insight to compare models
   • Create a new Insight and add the last two submitted models to this Insight for comparison.
   • Open the Insight you have just created by selecting the tile.
7. Open one of the models and create the baseline
   • Set a range or value for the following factors:
     • Operating Schedule: 12/6
     • Lighting Efficiency: 0.3 – 0.7 W/sf
     • Plug Load Efficiency: 0.6 W/sf
     • HVAC: ASHRAE Heat Pump
   • Save this scenario and rename it as Baseline
8. Select Back to Insight
9. In the Model Comparison panel, select the baseline scenario and compare the performance of each simulation.
10. Switch between the Visualization options of each model to see the computed heating and cooling loads.