Assemblies Versus Curtain Walls – When to Use

Assemblies Versus Curtain Walls – When to Use

There are two ways to approach storefront conditions on a building – by using window assemblies or by using curtain walls. Before choosing, you need to understand the differences between the two objects:

- Window Assemblies are typically placed in a wall, similar to a door or window. The assembly is simply a frame for doors, windows, spandrel panels, etc. that need to placed as one object, rather than a series of individual objects placed side by side in a wall.
- Curtain Walls are independent objects. For example, if the storefront is self-bearing, and the frames/mullions are the structural elements, then a curtain wall object should be used. Similar to assemblies, the curtain wall is simply a frame for doors, windows, spandrel panels, units, etc.

Therefore, how the component behaves structurally really dictates which object you’re going to use. If you’re placing a frame in the plan that is supported by a wall or other means of framing, then you’d use an assembly. If the frame is self-supporting, then you’d use a curtain wall. Here are some examples of what each will look like in plan.



Example 1 – Use an Assembly!

In the example above, the plan is showing a cleaned, filleted corner. Since a curtain wall treats itself as one continuous object, the cleaned corner can’t be made, as it would have to include a line indicating the mitered frame. Example 1 is the correct way to draft when the storefront is NOT a load bearing item. On the other hand, the below example would typically be built in two pieces, and would ship to the site as such – so the image would really have to look something like this:


Example 2 – Use a Curtain Wall!

So, if you’re looking for your plan to look like example 1, you need to use an assembly as part of a wall. If the storefront is load bearing, then it needs to look like example 2 and be created with a curtain wall object. To get the curtain wall to show a mitered corner correctly you’ll need to edit the profile for the frame. The following is a series of steps to use to get a frame to show the mitered corner or a boxed corner correctly.

Draw the segments of a curtain wall. The style example is a manually spaced grid, with horizontal and vertical mullions. Move the individual segments using end point snaps if you want to clean the curtain walls up along an inside or outside edge.














After lining up the curtain wall, right click on one object and choose Frame/Mullion – from the flyout, choose Add Profile. The program will prompt you to pick an edge; in this case I chose my vertical wall, the top edge of the frame. A dialogue will appear:
















Leave Profile Definition set as start from scratch – if this change is only going to apply at this location, then check As Frame Profile Override under apply profile. I also give this profile a unique name, like Front Façade Left Edge.















The edit-in-place features will now appear. Use the grips to stretch and edit the edges of the frame to the shape you need. In this case, we’re simply making this one corner larger and using a butted frame for our horizontal curtain wall.














And here’s the example with a mitered corner:














This gives us a technically correct corner condition that reflects how the frame will ship, and addresses how a storefront that is a bearing object can be created in Architectural Desktop. Hopefully this will help the users decide when to use each object – enjoy!

Got Desktop? Use It!

It still amazes me how many users buy software, then never get around to actually using what they've purchased. Since I'm from the South (North Carolina to be specific), I liken this to buying that brand new Ford F250 pickup truck with all the bells and whistles, then hooking it up to horse to pull it around because "I don't have time to learn how to drive". That's a sad and unfortunate excuse. At some point, you had to make time to learn how to use CAD in the first place - was it really a waste of time, or would you be better off still drafting on the board?

Of course not - the proof is in how much CAD is used today. While there may be some specific features in a program that we either don't need or think are too difficult to learn to use, there are always improvements to most software programs that are worthwhile tools - and it's you, the user, that are driving companies like Autodesk and Microsoft to improve their products.

Let's address the "I don't have time" issue first. Using plain AutoCAD and drafting with lines, arcs and circles worked great when comparing your work to what you did on the board. You could make changes to lines and adjust penweights, relocate items quickly, etc. in dramatically less time than it took to using the electric eraser to wipeout what you've drawn and re-draft. You're also not wearing out a sheet of paper (although you are wiping out a lot more trees now!) when using CAD. At some point most people had to sit down and learn CAD, as opposed to board drawing. You also had to learn how to use a computer, and Windows, and how to set up a printer, and how to back your files, etc. So the learning curve of going to CAD from the board was dramatically larger than what we're talking about now, which is simply fine tuning methods. You made time to learn before, and the end users were demanding CAD files - that's ultimately why most users switched (you know - the guys who write the checks).

Now the idea is take the repetitive tasks such as setting layers, offsetting lines to make walls, creating and maintaining blocks for symbol libraries to use for doors, windows etc., and instead of spending all that time creating and maintain those items, programs like Architectural Desktop take care of that for us. The time savings is in the little tasks - how many times does an AutoCAD user set a layer current each day (which is roughly equal to how many times a woodchuck chucks wood - you get the picture). Other time savings from using a program such as ADT that has display controls and the Project Navigator wind up drawing the building once and creating views from that base plan - thus eliminating the need to make multiple changes to the same objects.

How long does it take to learn ADT? Most of users that go through training get pretty proficient within 6-12 months with the whole package, usually with 2-4 days of training and follow up support. They start with learning drafting basics such as adding walls doors and windows, then move on to other features such as scheduling, sections, elevations. ADT is not a program that requires you to use every feature when you use it - same as AutoCAD. The overwhelming number of companies we work with that fail do not invest in training - either by buying book or by investing the time, or by working with their reseller or consultant to get training on what they really need. They don't see a return because buying the tool is like buying the car - at some point you have to learn how to drive - who taught you? The other failures occur when time is invested in training, but the users don't follow through immediately by putting what they've learned to use - try remembering every conversation you had last week - can you remember everything you did or said?

There's been a ton of studies of how much more productive BIM and object based programs are than line-based drafting, so I won't go into too much detail here (email me if you want some links), but most clients get a minimum of 15% increased productivity within the first year. Do the math - if I usually spend 60 hours on a project at $60 per hour, that's $3600 - if I do the same project in 45 hours, I'm at $2700 - the difference alone on one project usually saves you enough money to get some basic training. Add that up over a year with a dozen products - and you've paid for the software (a FULL SEAT price) and a year's worth of training.

The biggest benefit to me was that I found that I was leaving work at the end of the business day - instead of pulling all nighters. My home time is a heck of lot more valuable to me than a dollar figure - since you can't buy that time back. How many days are you going to be able to buy back this year from your kids, your wife, your boat, all the great reality shows on TV....???

I'll address some of the other issues and other products later - think about and tell me what you think.

And go home - it's quittin' time, and the fish are biting....!

David B.

Here's a couple of quick tips for Architectural Desktop from Mike Zeeveld in our Charlotte office:

Architectural Desktop Users…
Here are some helpful hints for producing images in Architectural Desktop to show your client or take further and/or apply color for a better presentation look.

Napkin

Do you need to make your drawing(s) look like it was hand drawn? Create freehand sketches from objects in a drawing. There are 3 options which include Tight, Loose and Messy.

Command:_AecNapkin




Hidden Line Projection

Create a 2D block type image from a 3D view. Rotate your view to the position you want. Exectute the Hidden Line Projection command. Specify an insertion point, answer yes to show in plan. You're done!

Command: _AecCreateHLR



You can also use these tools in Building Systems - just type in the commands and you're off to the races!