Founded in 1909

Irwin & Leighton was founded in 1909. The company maintained its headquarters in Center City Philadelphia until 1974 when it moved its operations to King of Prussia.

Employee Held

Irwin & Leighton’s stock is held exclusively by its key employees. Stockholders include personnel from virtually every department in the organization and include corporate officers, project managers, estimators, superintendents, accountants, secretaries etc. This unique structure promotes vitality within the organization and a motivation for employees to excel.

Long Term Relationships

Irwin & Leighton’s hallmark is its long-standing professional relationships with its customers and employees as well as its surety, banking, accounting/tax and insurance partners. Many of the company’s client relationships are measured in decades. The average employee tenure exceeds 10 years. Consequently, daily operations are focused on providing outstanding service to every customer in order to earn their trust and future business.

Broad Experience and Expertise

Irwin & Leighton has extensive experience in the corporate, educational, healthcare, pharmaceutical and retail sectors for projects involving new construction and renovation of existing facilities. Many of these projects have included historical renovations and/or sustainable design.

Customer Focus - Project Size

Irwin & Leighton is customer oriented and is, therefore, flexible as to contractual role and the size of project it is willing to undertake.

The company is organized to effectively provide services on a construction management, general contracting or design-build basis. Recent project sizes range from less than $1 million to over $70 million.


Irwin & Leighton is organized to provide services on a union or open shop basis dependent upon customer preference and geographic location of the project.

Regional Capabilities

Irwin & Leighton maintains operating capabilities in Pennsylvania, New Jersey, Delaware and Maryland. In addition to its headquarters in King of Prussia, the company maintains satellite offices in Allentown, Pennsylvania, and Princeton, New Jersey.