Goals

  1. Learn how to create a model that will run smoothly in Sefaira (this also includes modifying existing models)
  2. Get access to a model (either by creating or by downloading one) that will run smoothly in Sefaira for your first test run!

This chapter provides essential knowledge for using Sefaira. Depending on your subscription, please look at the section for either SketchUp or Revit models.

TIP

If you’d like to jump over this section and just start looking at Sefaira analysis within a model, you can download our sample SketchUp model at the bottom of this page.

SketchUp

Before You Begin Modeling

Keep in mind that the goal is to create a conceptual model — your geometry can be very simple in order to run an effective energy analysis. Focus on creating the “outer shell” of your building with representative glazing; there is no need to model details such as window mullions or changes in material. Click here for more reading on modeling strategically for Sefaira. If you are working with an existing model which needs simplified, please view this article

Example:

In this example, each facade is considered EXACTLY the same from an energy performance standpoint. The difference is that the Before image has ten planes (eight window planes and two wall planes), and the After image has two planes (one window plane, one wall plane). Less is better.

BEFORE

Facade Before

AFTER

Facade After

Modeling Requirements

TIP

Watch this webinar to understand how you can build a design and analysis model all in one. 
 

In order to achieve a successful and accurate analysis, the following requirements must be maintained:

1. Model using single, thin planes

Do not model thicknesses for roofs, walls, floors, glazing, or shading. This will adversely impact the analysis results and possibly result in upload errors.

mr_1

2. Place the ground floor at the Z = 0 axis

Models should be built up from the Z = 0 axis plane. An error will occur if there is not a floor plane at the Z = 0 axis. Anything below Z = 0 will be analyzed as sub-grade.

Note: Basements should ONLY be modeled if the basement space will be an occupied space and/or a mechanically heated/cooled space.

mr_2

3. Align model with the central axis

Models that are far from the central axis (X=0, Y=0, Z=0) will impact the Sefaira analysis. Place the model close to the central axis.

    

4. Verify entity type assignments

While in the Entity Palette, verify that entities have been assigned accurately by clicking the ‘Show Entity Types’ button. Reassign entities that were misinterpreted by right clicking on the plane, and selecting the correct entity from the menu.

When assigning entity types, keep the following key points in mind:

  • All contextual buildings should be tagged as ‘Shading’.
  • All interior planes should be tagged as ‘Interior Walls’..
  • Any plane on the building that does not enclose a mechanically heated/cooled space should be tagged as shading.
  • In SketchUp 2014 ONLY, there is currently a bug concerning glazing.

5. Clean up model and check total plane count

  • Delete, hide or put on a layer which is turned off any groups, components or planes that are not a part of your project and its context.
  • RTA runs will occur on-demand for models with over  8,000 planes and 1,200 glazing planes. Plane counts over 5,000 glazing planes are currently not supported. 

TIP

If you’re unfamiliar with using SketchUp, you can access some excellent video tutorials here.

Get Started with a Model

If you prefer just checking out Sefaira without creating or adapting a model yourself, you can use one of our sample models to get started:

WHAT YOU’VE LEARNED

  • You can now create new models that will work with Sefaira
  • You can also modify your existing models to work with Sefaira
  • You are ready to get started using Sefaira!