If you have been working with custom MvBlocks in AutoCAD Architecture 2008, you may have noticed that they don't come in at a scale of one.  MvBlocks, like those for appliances, should only be scaled when changing from Imperial to Metric units but now they are scaled based on the new Annotation Scale feature introduce in AutoCAD 2008.

AutoCAD 2008 does not have the "Annotation Plot Size" option that AutoCAD Architecture 2008 has on the Scale tab of the Drawing Setup (type "Units") dialog.  Essentially there is now a type of redundancy in the ACA system where one value sets a general insertion scale while the other provides the automatic adjustment.  Both are only supposed to affect Annotation Objects but I have found that for some reason all MvBlocks are treated like Annotation Objects upon insertion from the Content Browser and Tool Palettes. 

After working on this problem from as many angles as I could come at it from, including using the "AnnoAutoScale" system variable, I came to the conclusion that it is a software bug.  Then, I focused on the cause of the problem so I could circumvent it.

In the illustration to the right I show that I have used the "Edit Scale List..." button on the Drawing Setup dialog to add a custom Scale to the default list.  The new scale I have created is specifically for inserting MvBlocks at a scale of one so I named it "MvBlocks".  The custom Scale value has to be the opposite or inverse of the "Annotation Plot Size" listed on the Scale tab.  By inverting this value, the scaling bug is negated.

In the illustration to the right I show how a custom MvBlock from one of ARCHIdigm's eKits will now insert at a scale of one when the new "MvBlocks" Annotation Scale is used.

To make this new Annotation Scale value part of your regular work, you will need to add it to your template files.

I have no idea why this bug exists but this is the only work-around solution that I have been able to come up with.  I am currently using ACA 2008 on Vista 64 so there is the possibility that this bug doesn't exist on other OS's but in case it does, you will need this tip.