The Architectural Desktop Curtain wall is one of the most powerful tools in the ADT 3.3 toolkit. However, most designers have found the dialog box quite intimidating. Those that have spent the time learning to master this tool have found it very rewarding. However, what about the average user that needs to make a new storefront or curtain wall design quickly? Surprisingly, curtain walls can be designed with very little interaction with the style dialog. This is both fast and user friendly.

The first step in creating a curtain wall quickly is to draw a 2D Layout Grid. The layout grid tool can be found under the ADT Desktop->Layout Tools->Add Layout Grid (2D). This tool has the exact same dialog box both the column grid and ceiling grid tools, so it should look familiar. As with these other tools, I never worry about the initial size, but just throw a swatch on the screen and edit the size later.

Place the layout grid in a plan view. Once placed, select the grid and right-click for the ADT context sensitive menus. Selecting "2D Layout Grid Properties…" will allow the rules for the grid to be edited. For this example, I’ve disabled both the X and Y axis automatic spacing on the Dimensions tab. This lets me grip edit the grid on the screen to the correct size. Now I’ll simply drag the nodes of the grid around to design my curtain wall. If I need to add or remove grid lines, I can again use the right-click menu and select X–Axis or Y-Axis tools. Or perhaps you already know the dimensions of your curtain wall. In this case you can simply edit the X-Spacing and Y-Spacing directly in the 2D Layout Grid Properties panel.

Most of the layout grid lines represent the centerline of mullions. This is true except for the outer edge of the grid, which will eventually become the frame element. The frame, by default, is always placed to the inside of the layout grid. I don’t worry too much at this stage if this is not the case. These settings are easy to change later when editing the frame or mullion properties.

From the Design menu, select Curtain Walls->Convert Layout Grid to Curtain Wall. You will be prompted to select the grid and then asked if you would like to keep or erase this layout grid. I typically keep my sketch geometry, but this is just a personal preference. The next prompt asks for a "Primary Division". Depending on the final design select either horizontal or vertical. In my example, I selected vertical for unbroken vertical mullions from top to bottom. Finally, ADT prompts for a new Curtain Wall Style Name. After entering a name, ADT will add a new curtain wall definition to the Style Manager and create a curtain wall along the X-Axis of the sketch geometry. Notice that although the layout grid was drawn in plan, the curtain wall was correctly placed standing up. In fact it doesn’t matter whether the layout grid is drawn in a plan or an elevational view; it will always convert to the correct vertical orientation.

Select the new curtain wall and right-click. From the right-click menu select "Edit Curtain Wall Style…" If you explore this dialog, you’ll see that ADT created vertical divisions for the primary grid and filled out the manual spacing dimensions of the grid. Any of these values can be edited now or later if the design should change. The "convert to" feature was quick, but didn’t allow for a lot of choices. The new curtain wall used the system’s default settings for frames, mullions and glazing so these are probably the wrong size.

These basic settings of the curtain wall can be changed by selecting the component and adjusting its values. To make this a storefront design and allow for a door, the bottom mullion can be turned off. This is done by selecting "Default Mullion Assignment" and clicking on the "Left, Right, Top, Bottom" column. A small button is exposed which gives us access to the frame position controls. Un-checking bottom eliminates the bottom frame.

The new style also uses the system settings for the sizes of frames, mullions and glazing. For the "Default Frame" I adjusted the width – which is the face of the frame – to 2" and left the depth of the frame at 6". I repeated this for the default mullion. There are other settings, which could be adjusted, such as offsets front to back or custom shapes could be added in the frame and mullion profiles. The names of each of the elements can also be changed for faster future reference, but if in a hurry, just leave things as they are. With this technique, complex naming is avoided and ADT does most of the work.

With so many edges and lines, it can be difficult to pick the correct object when editing a curtain wall. To assist the design process, turn on the Cell Markers by selecting the curtain wall and selecting Cell Marker->All Visible. The Cell Markers perform several tasks.  First they make selecting the glass panels quicker. You can pick the marker in lieu of trying to find the edge of the glass. Secondly, the arrows indicate the direction the curtain wall was drawn. Panel 1 is at the bottom and then each panel is numbered upward from there. If the curtain wall used a horizontal division as the primary grid, they would be numbered from left to right. I typically leave these markers visible as I design. And those familiar with configuring display representations will want these markers placed on a non-plotting layer so they can always remain on.

To make the design more interesting and allow for doors to be placed in some of the panels, several adjacent panels can be combined to make a larger panel. Simply select the curtain wall, right-click and select Overrides->Merge Cells. Pick any two adjacent cell markers and the mullion between the two is eliminated. Repeat this as needed to refine the curtain wall design. As you can see, starting with a few extra grid lines can be very helpful.

If we wanted nothing more than a simple glass curtain wall, the design process might stop here. The next few steps will demonstrate how simple it is to create very intricate curtain wall designs. For our example, I want to first add in three doors in the larger bays.

Open the curtain wall’s style editor from the "Edit Curtain Wall Style…" option on the right click menu. All of the items below Element Definitions on the left panel are the curtain wall’s kit of parts. Right now the kit of parts is very small, but we can add in as many different frame sizes, mullion sizes and panel types as we wish. We are also not required to use these parts anywhere in the design. They are simply a library of items we can draw from as the design evolves and is refined. By selecting the Infills category on the left, we see the Default Infill. This is set to 1" thick glass by default, but could be changed if desired. You’ll also note settings for alignment and offset. These two settings allow the panel to be place in the correct front to back relationship within the wall.

At the lower right corner of the right panel, there is a button that adds in new elements. I added in a new element and then selected "Style as the Infill Type:. This option exposes a list of possible items that can be inserted as curtain wall panels. I chose the Hinged – Double – Full Lite door from the list. Of course if the right item was not on the list, it would first need to be created with the correct tool within Style Manager. Return to the drawing but make sure to use the OK button or your additions to the curtain wall will be discarded.

I did make one adjustment to the door style before starting this last step. I set the door style definition to adjust the width of the door’s frame to 0". This effectively turns the door’s frame off and lets the mullions from the curtain wall be used as the door frame. In a typical commercial curtain wall this is desirable. If we were constructing a wood storefront, the door frame could be used along side the mullion to illustrate a frame and structural mullion condition.

Now that the doors have been added to the curtain wall’s kit of parts, it can be placed in any opening. Select the curtain wall and use the Overrides->Override Cell Assignment tool from the context-sensitive right-click. Look at the AutoCAD text screen <F2> and you will see you are presented with a list of available infill panels. Select 2 and the door will appear.

We do need to take a few precautions when using this technique. The door will be scaled vertically and horizontally to fit the space between the mullions. So be sure to take this into consideration as you space your 2D Layout Grid. Since the mullions are 2" and measured from center-to-center, I spaced the mullions 6’-2" apart for the door. Any fine-tuning of these dimensions can be done in the curtain wall’s style dialog.

This cell override tool is the fastest method for creating unique curtain wall designs. It also allows for fast changes in the future without spending time trying figuring out the complexity of the style dialog.

The next steps illustrate the use of Curtain Wall Unit Styles. Curtain wall units are nothing more than small curtain walls used as panels inside larger curtain walls. Using curtain wall units makes complex curtain wall design much faster than trying to use the nested grid feature from the curtain wall style dialog. Since these elements are just small curtain wall parts, the techniques and dialog boxes will be identical to the main curtain wall’s dialog.

For this example, I started with a 2D Layout Grid just as I did with the main curtain wall. This time, I retained the Automatic spacing feature of the layout grid tool and set the X-Axis to "Space the Lines Evenly: 1" – creating one horizontal bay. In the Y-Axis I created 6 even bays with the "Space Lines Evenly:" option. With the even spacing feature, it does not matter how large or small the original grid is created. It will automatically scale itself to the correct size once assigned to the curtain wall cell and in this case divide any bay into 6 equal parts.

The curtain wall unit style is now created using the Design->Curtain Walls->Convert Layout Grid to Curtain Wall Unit tool. Just as before, a unit is created using all of the systems default settings. Since this is going to be an infill panel between the doors, portions of the frame are not needed and can be turned off.

This particular panel will be used to divide the sidelights next to the doors with smaller glazed areas. It will also provide the lower frame or kick panel of the curtain wall. As we did with the main curtain wall, enter the curtain wall unit’s style dialog. To create the kick panel, turn off all but the bottom frame. Once this is done, set the width of the frame to 12". Since this frame is used as a horizontal element, the 12" is really the frame’s height. ADT always refers to the face of the frame as the width. The default 6" depth will be flush with the other frames and mullions we created. If you were to return to the drawing at this point, you would find that all but the bottom panel is the same size. The new bottom frame has cut off the lowest panel. To retain six equal glazed areas, adjust the "X:" values under the frame’s settings. The X and Y offsets allow the frame to be moved from its default location. Just remember; frames align to the outer edge of the curtain wall and mullions align along their centerline. Using an X value of 12" moves the frame away from the center of the wall. Using a negative value would move it close to the center of the wall.

Getting the curtain wall unit into the proper locations is the same as used in inserting the door. First add a new Infill definition to the main curtain wall’s style. Set this new definition to be style based and use the newly created curtain wall unit as the infill’s style. As many different curtain wall units can be created as needed for your design.

If we were limited to just horizontal and vertical frames and mullions, life would be dull. Since every designer needs to maintain his reputation by blowing the project’s budget, Autodesk gave us another way to create curtain walls and curtain wall units. Just draw some lines. Maybe add in a few circles or an arc or two. From the pull down menus, select Design->Curtain Walls->Convert Linework to Curtain Wall Unit. Grab the sketch and instantly you have a new curtain wall unit.

There are a few rules that make this tool a little more difficult to use. The curtain wall elements created from a sketch do not resize, so you need to make sure your sketch is correct first. The outer edge needs to be closed. Mullions should touch the outer edge of the design. Also these units are inserted at the lower left corner of a panel at the mullions center lines. So some additional planning might be needed.

Another mystical element of making curtain walls and units with this technique is that they don’t show up in style Manager. In fact if you tray to edit the objects style, a cryptic message about in "edit in place" being active. Unless this new unit can be added to the Style Manager library, it won’t show up when we tray to place it in a panel as we did the door.

There is a solution. Once the basic sketch is a curtain wall unit, simply select Edit in Place->Save Changes… from the context-sensitive right click menu. This adds in a new style definition based on the sketched unit. It can now be edited and adjusted as we did with the door and previous curtain wall unit.

So far the curtain wall looks great in 3D and in elevation. However, in plan I prefer to see the inner and outer edged of the frame – not just the glass. The simplest way to include this extra linework is to adjust the curtain wall’s display plan display representation. I always set the cut plane for the plan view so that it is flush with the lowest mullion. In this case, I set it to 12". Actually the top of any mullion would do, but the math is usually simple for the lowest mullion.

Curtain Walls, Curtain Wall Units and Window Assemblies all share the same design techniques and dialog boxes. So how do they differ? Curtain walls are free standing walls. Curtain wall units are used as panels within either Curtain Walls or Window Assemblies. Window Assemblies are curtain walls used within walls. If you need a office door with a side light – it is a window assembly. If you need a storefront – it is probably a window assembly.

As with any design, plan ahead. I often create a sketch on yellow trace with color pencils. Having this simple diagram speeds my design of the main grid and all the needed door, window and curtain wall unit styles. Think about the rules behind each of the elements. Will the wall use explicit spacing? Will it divide a space evenly or will it create equally spaced opening? Adjust your initial 2D Layout Grid to meet these goals.