The estimated useful lives of the Company’s property, plant and equipment are as follows:
Laboratory equipment5 years
Manufacturing equipment5 years
Office and computer equipment3 years
Buildings
35 years
Leasehold improvementsShorter of remaining lease term or estimated useful life
Property, plant and equipment, net consist of the following (in thousands):
December 31,
20242023
Land$31,243 $31,243 
Laboratory equipment— 8,291 
Buildings102,433 102,433 
Office and computer equipment509 831 
Leasehold improvements— 1,424 
Manufacturing equipment— 2,017 
Total property, plant and equipment, gross134,185 146,239 
Less: accumulated depreciation(4,779)(7,555)
Total property, plant and equipment, net$129,406 $138,684 

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.