Exhibit 8.1

List of Subdiaries, Including Their Jurisdiction of Incorporation and Names Under Which They Do Business



|                                         |  |                              
|---------------------------------------- |  | -----------------------------
|Legal and Business Name                  |  | Jurisdiction of Incorporation
|Eastbrook Industrial Constructors Inc.   |  | Alberta, Canada              
|Grand Sierra Construction Inc.           |  | Alberta, Canada              
|Grand Sierra Equipment Ltd.              |  | Alberta, Canada              
|Health Partners Kingston Ltd.            |  | Alberta, Canada              
|Health Partners Markham Ltd.             |  | Alberta, Canada              
|Health Partners Ottawa Ltd.              |  | Alberta, Canada              
|Melloy Industrial Services Inc.          |  | Alberta, Canada              
|Monad Industrial Constructors Inc.       |  | Alberta, Canada              
|Pacalta Construction Inc.                |  | British Columbia, Canada     
|PCL Builders Inc.                        |  | Alberta, Canada              
|PCL Capital Inc.                         |  | British Virgin Islands       
|PCL Construction Group Inc.              |  | Alberta, Canada              
|PCL Construction Holdings Ltd.           |  | Alberta, Canada              
|PCL Construction Management Inc.         |  | Alberta, Canada              
|PCL Construction Resources Inc.          |  | Alberta, Canada              
|PCL Constructors Bahamas Ltd.            |  | Nassau, Bahamas              
|PCL Constructors Canada Inc.             |  | Alberta, Canada              
|PCL Constructors Eastern Inc.            |  | Alberta, Canada              
|PCL Constructors Inc.                    |  | Alberta, Canada              
|PCL Constructors Northern Inc.           |  | Alberta, Canada              
|PCL Constructors Westcoast Inc.          |  | Alberta, Canada              
|PCL Design Builders Inc.                 |  | Alberta, Canada              
|PCL Design Constructors Inc.             |  | Alberta, Canada              
|PCL Fabricators Inc.                     |  | Alberta, Canada              
|PCL Industrial Constructors Inc.         |  | Alberta, Canada              
|PCL Industrial Management Inc.           |  | Alberta, Canada              
|PCL Intracon Power Inc.                  |  | Alberta, Canada              
|PCL Tools Inc.                           |  | Alberta, Canada              
|4102410 Canada Inc.                      |  | Northwest Territories, Canada
|A.T. Curd Structures, Inc.               |  | Colorado, U.S.A.             
|C.C. Conley & Sons, Inc.                 |  | West Virginia, U.S.A.        
|Company 54, Inc.                         |  | Nevada, U.S.A.               
|Green Development, Inc.                  |  | Delaware, U.S.A.             
|Green International Guyana, Inc.         |  | Delaware, U.S.A.             
|Green International, Inc.                |  | Iowa, U.S.A.                 
|Green Investments, Inc.                  |  | Delaware, U.S.A.             
|Green Leighton Contractors, Inc.         |  | Delaware, U.S.A.             
|Nordic PCL Construction, Inc.            |  | Hawaii, U.S.A.               
|Northland Alaska, Inc.                   |  | Alaska, U.S.A.               
|PCL Civil Constructors, Inc.             |  | Colorado, U.S.A.             
|PCL Construction Associates, Inc.        |  | Minnesota, U.S.A.            
|PCL Construction Enterprises, Inc.       |  | Colorado, U.S.A.             
|PCL Construction, Inc.                   |  | Colorado, U.S.A.             
|PCL Construction New Mexico, Inc.        |  | New Mexico, U.S.A.           
|PCL Construction Resources (U.S.A.) Inc. |  | Colorado, U.S.A.             
|PCL Construction Services, Inc.          |  | Colorado, U.S.A.             
|PCL Environmental, Inc.                  |  | Arizona, U.S.A.              
|PCL Industrial Construction, Inc.        |  | Colorado, U.S.A.             
|PCL Industrial Construction Co.          |  | Colorado, U.S.A.             
|PCL Industrial Services, Inc.            |  | Colorado, U.S.A.             
|PCL U.S. Holdings, Inc.                  |  | Colorado, U.S.A.             
|Rialto Holdings, Inc.                    |  | Colorado, U.S.A.             
|PCL Constructors Pacific Rim Pty Ltd.    |  | Victoria, Australia