IT TOOK A LONG WHILE, but Ontario’s Assessment Review Board (ARB) has injected a little common sense into the chaotic world of municipal assessment.

The board last week overturned a decision of the Municipal Property Assessment Corporation (MPAC) to designate Ken Filsinger’s Sign Needs plant on Orangeville’s Centennial Road as an industrial, rather than commercial, operation, at an annual cost to the business of more than $4,000.

At a hearing last June, the ARB was told that not only had Sign Needs enjoyed a commercial designation at its previous site, but all its competitors enjoyed the same designation.

Mr. Filsinger estimates that he would have needed an extra $100,000 in added annual sales to cover the unexpected tax increase.

He observed — correctly, in our view — that the industrial classification was “wrong from the start ... meant for large factories, not a father/son operation like this.”

If nothing else, the successful challenge illustrates the need to replace the current assessment system with something far less judgmental — ideally, with a taxation system based simply on the quantity of land and occupancy space owned.

Clearly, some signs are manufactured and some sign companies are huge, perhaps even multi-national, while others may be even smaller than Sign Needs.

But it makes no sense to be basing a municipality’s revenues either on someone’s suspicion as to the market value of a given property or as to whether the business enterprise is primarily manufacturing rather than marketing.

And it strikes us as particularly strange that in the midst of the worst economic downturn since the 1930s any small business should be penalized for doing its own manufacturing.

If MPAC exercises its right to appeal and (heaven forfend) is successful, Sign Needs and all other similarly situated businesses will be rewarded with lower property/business taxes if they stop making their own signs and have the work performed elsewhere. (That’s what happened when drug manufacturer Pfizer briefly stopped production at its Orangeville plant.)

We’re sure there are sign makers in New York State or Michigan who would love the business.