Generally, the estimated useful lives of assets are:
Land improvements5to40 years
Buildings and improvements7to40 years
Plant, office and lab equipment5to10 years
Property, plant and equipment, net, consist of the following (in thousands):
 March 31,
 20252024
Land and improvements$3,112 $3,162 
Buildings and improvements56,982 54,411 
Plant, office and laboratory equipment136,244 127,344 
Construction in progress10,296 11,409 
206,634 196,326 
Less: Accumulated depreciation(113,219)(103,515)
Property, plant and equipment, net$93,415 $92,811 

About PP&E Disclosures

The PP&E disclosure details a company's physical asset base — land, buildings, machinery, and equipment — along with the depreciation methods and useful life assumptions that determine how these costs flow through the income statement. Capitalization policy thresholds reveal management's judgment on the boundary between expense and asset, directly affecting both reported earnings and asset values.

Key signals: changes in estimated useful lives or depreciation methods can materially shift reported earnings without any operational change. Compare capital expenditures against depreciation expense — when capex consistently trails depreciation, the asset base may be aging and underinvested. Watch for large asset impairments or write-downs that signal overvalued carrying amounts. Asset retirement obligations reveal future environmental or decommissioning costs that are often underappreciated. Compare PP&E intensity (PP&E-to-revenue) against industry peers to assess capital efficiency and competitive positioning.