Hi - my name is XXXXX XXXXX I'm a Real Estate
litigation attorney. Thanks for your question.
As you know, a triple net lease means that the tenant or lessee agrees to pay all real estate taxes, building insurance, and maintenance
(the three "Nets") on the property in addition to any normal fees that are expected under the agreement (rent, utilities
The real estate taxes and building insurance should be pretty constant, and the maintenance is also fairly constant, so to have an assessment almost double the price is a little difficult to understand.
However, the bad news is that if your lease allows the landlord to make this increase, then you can't make the landlord refrain from making this assessment, but you can refuse to continue the lease (hopefully your lease gives you the right to accept or deny the amount).
IF the lease requires the increases to be justified, then you can request an accounting to make sure that the landlord is actually incurring new costs to justify the increase instead of just padding his botXXXXX XXXXXne.
The only saving grace would be is if your area has a rent control
ordinance to keep renters from being run off by high rents - - this is less common today than in years past, but it's likely something you can consider.