FenestraPro for Forma – Envelope Analysis Extension

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For release notes for the current version of the FenestraPro Envelope Analysis extension in Forma, please see HERE

Note: Our Code Database is being improved to support more regions. Code values will be calculated from metric values for regions which use metric units (metric U-values for all elements) and imperial units for USA locations (imperial R-values for roof/floors and walls) and imperial U-values for glazing.

You can review our current regional Energy Codes or request a new Code be added on this page HERE

Install the Extension

Go to Autodesk Forma online and open a project. It is currently recommended to use the Chrome Browser as other browsers may not be fully compatible. If you have view access only, you may need to join a project in your hub to get editing permission (please check if the project is locked or contact the project owner for access). Click on the ‘Extensions‘ icon. There are several ways to access this: (1) either on the left hand side toolbar, (2) on the main building modeller toolbar or (3) in the analyses options on the upper right of the screen.

Then click on ‘Add Extension‘.

Find the FenestraPro extension in the list and click on the Add button. Agree to the terms of use and then close this window. Refresh your browser to update your Forma screen with the new extension.

When you hover over the extension option now (‘Analyses by Extension‘), the FenestraPro extension should be listed (amongst others). Click on the extension to load it into Forma and it will display in the panel below.

When the extension loads, there is an information panel. You may review this and close the panel if you wish, using ‘dismiss‘. There are also buttons to link to this Support Page.

Select the Proposed Design

It is important to select the entire building that was modelled in Forma before using the extension. Selecting individual storeys or including the site context/surroundings should be avoided. Selecting only parts of the building will not produce expected results and the calculations may not complete. You may need to hover over a corner or roof edge to assist in selecting the entire proposed design.

It is best to finalise your design before using the extension, rather than starting analysis and then adjusting the building height/shape etc. If the model is modified while the already extension has launched, refresh your browser and select the entire model again (otherwise the original design will still be analysed). Then allow the application to calculate the overall results. Then adjust the glazing percentage that you wish to apply. Note: the less storeys the building has, the faster it will be to process calculations. You can select the roof of a building and push or pull in Forma to adjust the height or use the inputs on the right hand side panel to define storeys and storey heights.

Select an Energy Code

A default FenestraPro Energy Code is currently used for regions where actual Energy Codes are not yet in our database (these are typically countries that use metric units).

U-values used to calculate the results are as follows:

Wall 0.3067 metric u-value

Floor 0.5225 metric u-value

Roof 0.5225 metric u-value

Glazing 3.13 metric u-value / SHGC 0.39 / VLT 0.59

This default Code is used when no other energy standard can be found for the site location.

The default performance of model elements are assumed to be:
Wall = 0.31 u-value, Floor = 0.15 u-value, Roof = 0.15, Glazing = 1.53 u-value (metric values)

Wall = 18.32 R-value, Floor = 37.86 R-value, Roof = 37.86 R-value, Glazing = 0.27 U-value (imperial values)

Window to Wall Ratio

Next, select a Window to Wall ratio to apply to the Forma model. This will be the percentage glazing for the project. Use the slider provided to adjust the glazing percentage that you wish to apply. Once this is done, calculations will be performed. Please allow this to complete. Results will then display depending on the amount of glazing applied. Note: the less storeys the building has, the faster it will be to process the calculations.

Apply by Facade

First ensure that the model proposal has been selected in Forma and the extension has calculated initial results and areas.  You may use the tab key on your keyboard to help select the entire model.  Opening the Façades List before this is done will not display any information.

You may open controls for the Façades List which will allow you to set glazing percentages separately for individual Facades.

Click on the icon for slider controls beside ‘Apply by Façade’ to open a panel, listing all Façades on the model.  You can set the Total Window to Wall (WWR) ratio first  and then adjust values for individual Façades, or open the Façades List first and set separate glazing percentages here (the Total WWR for the overall model will then update).

Depending on the design, there may be multiple model planes facing one orientation. There may be several South facing facades for example.  You may highlight the Façade which you wish to adjust using the eye icon. The model will rotate to display and highlight this area for easy identification.  Use the sliders to adjust the window to wall ratio for that Façade. A Façade can be set to any percentage in increments of 5 (from 5% to 95%).  A Façade may also be set to zero percent.

Then use the ‘Apply Here’ button to update the Total WWR (window to wall ratio) for the model.  Results for Solar Load and Heat Gain will also update in the dials. The glazing zones displayed on the model will also update to reflect the current percentages.

Note: If you close the Façades panel and reopen, all Façades will reset to the value displayed for the Total WWR.  This will be acceptable only if all Façades have been given the same value.  If you wish to continue adjusting percentages for separate Façades independently, the Façades List must remain open. 

You may also minimize the Façades panel (to view more of the Forma screen), by using the icon shown. Façade settings will be preserved when the panel is maximized again.

Where Façades have been given separate values and the Façades List is closed, the values shown will reset and currently will not store the previous settings.

If the Façades panel is left open and the Total WWR is adjusted, this will override the Façades List.  Façade percentages will not update immediately but will update when the panel is closed and re-opened (as there is a one-way update only from the Façades List to the Total WWR).  Glazing zones will also update on the model. 

Multiple Models

If you have multiple proposed buildings in the project, close the Façades List and reopen it when switching from one model to another, to allow it to reset with the new list (and possibly new number) of Façades for the active building.

Currently, there is no redistribution of glazing percentages throughout the model (e.g. if the Total value is defined and one Façade is adjusted, other Façades do not adjust to maintain the total).

Construction Types

The assumed default Construction Types in Forma will be listed here under the dials, with the associated thermal properties. Currently these are not editable in Forma. If you choose the option to ‘Use Code Benchmark Properties‘ (which assumes that the model will have thermal properties that comply with the target Energy Code), the properties listed for the Forma Construction Types here will still display as before and will not update. In the example below, the wall thermal value does not comply with the selected Energy Code and displays in red when the setting is ‘Use Modelled Properties‘. If a value does not comply with the selected Energy Code, it will show as red. A value which does comply with the target Code values will display in black.


Results will then display in the dials for Glazing Percentage on the model, U-Value for the model facade (including walls and glazing), Solar Load and Daylighting (total for the model) based on the window to wall ratio selected and if you are using the construction types’ properties or the selected Energy Code values. The arrow in the dial will indicate where the current result value is located within the range provided for that parameter. Results will be displayed as metric or imperial values depending on the model location.

Element Areas

These areas will be displayed for Glazing, Walls, Roofs and Floors. These areas will be displayed as metric (m2) or imperial (ft2) depending on the model location.


Known Issues

  • Currently the Basic Building type in Forma is supported to create geometry for analysis (‘Line Building’ and ‘House’ types are not yet supported)
  • Results will not be produced if the entire model is not selected (if only one floor or selected floors are selected). In this case please select the entire proposed design.
  • Adjusting the Forma model while the Envelope Analysis extension has already loaded will not automatically update the extension. In this case, please use the Escape key on your keyboard to disengage from the editing mode and select the model again to analyze.
  • Larger models will take a little longer to process since glazing has to be applied to each storey, so please allow the calculations to complete.
  • Energy Code values that are referenced may be simplified where there are multiple recommendations for construction types (eg. flat roof, sloped roof, heated/unheated floors, element materials wood/metal etc)
  • If you wish to add or delete internal walls to/from the model, you may need to refresh your browser to update the extension with the new model condition. It will then recalculate the results.
  • Roof area should generally match the Ground Floor area displayed but may sometimes be different – this issue is being explored
  • If you have multiple buildings in your project, only one can be analyzed at any one time. Selecting all buildings will only produce results for one. Currently, as you select another building, calculations will commence and then display for this (results for the previous building do not continue to display but are stored if you wish to return to the first building).


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