After searching for a new headquarters for five years, Seiler Instrument and Manufacturing Co. Inc. is moving its corporate offices, manufacturing, survey and microscope divisions from Webster Groves to a single building in Tree Court Industrial Park in Kirkwood.

The move combines all of Seiler’s operations into one 148,000-square-foot facility at 3433 Tree Court Industrial Blvd.

Seiler’s Webster Groves headquarters was so cramped that co-owner Tom Seiler said the company has lost business due to the lack of space.

Seiler said his search for a new location ended with the company’s $5.8 million October purchase in Tree Court Industrial Park, which will nearly triple the amount of space the company occupies.

Seiler is financing the deal through UMB Bank.

Seiler is a contract manufacturer, specializing in fire-control equipment, and a distributor of surveying instruments, microscopes and Zeiss planetaria. The manufacturing division produces optical fire-control equipment and components, such as periscopes, telescopes and gunsights, primarily for the military. The division accounts for about half of Seiler’s revenue, which was nearly $50 million in 2008.