Mine is about 15% of NW and paid off, I would consider it an investment in that I could always do a reverse mortgage if all else failed.
"If it didn't have bones in it, it wouldn't be crunchy now, would it?" -M. Python
Age 50, DW is 54, 1.4M split 25 Stock, 40 Mutual Funds, 25 Bonds, 5 Commodities, 5 REIT. Own Home, no debts.