Look in the output subfolder of the UI folder, e.g. DrawArtUI/output and you should see a zxp file. Install this file using the Adobe Extension Manager.
The only output folder in my SDK folder area is the one in the samplecode where the API files are:
C:\Users\198339\Desktop\AI_CC_2014_SDK_Win_430_3\Adobe Illustrator CC 2014 SDK\samplecode\output\win\Win32\Debug
There are no .zxp files anywhere in my SDK folder area. Do I need to do something to create them other than compiling the associated project in the non-ui folder? For example, I compiled \samplecode\Tutorial\Tutorial.vcxproj which created the.AIP file.
Sorry, I have an older version of the CC SDK.
Looks like they converted all the flex ui stuff to html5 in the CC 2014 (and 2014.1) SDK and didn't include the built versions. I have never built a plugin with an html5 ui. This might get you started: