Detect Windows Kit 8.0 and Windows Kit 8.1 SDKs

I'm working on a test script for Windows Tablets, Windows Phones and Windows Store apps. The scripts are mostly working for under Visual Studio 2012 and Windows Kit 8.0 SDK. It appears Microsoft changed some things for Visual Studio 2013 and Windows Kit 8.1 SDK, and its causing a failure:

cl.exe /nologo /W4 /D_MBCS /Zi /TP /EHsc /MD /FI winapifamily.h /D_ARM_WINAPI_PARTITION_DESKTOP_SDK_AVAILABLE=1
/DWINAPI_FAMILY=WINAPI_PARTITION_DESKTOP /Yc"pch.h" /Fp"pch.pch" /c pch.cpp
pch.cpp
C:\Program Files (x86)\Windows Kits\8.1\include\shared\winapifamily.h(116) : fatal error C1189:
#error :  Unknown WINAPI_FAMILY value. Was it defined in terms of a WINAPI_PARTITION_* value?
NMAKE : fatal error U1077: '"C:\Program Files (x86)\Microsoft Visual Studio 12.0
\VC\BIN\x86_ARM\cl.exe"' : return code '0x2'

How can we detect the Windows Kit SDK being used?