Harrison West Case Study

Harrison West Case Study: Introduction

The Harrison West Condominium Association required a re-pipe of their historic 24 residential tower situated in the desirable PSU area of Portland Oregon. Community Engineering Services, PLLC formed a team with engineering specialists Dan Robles, PE,  David Coles, PE, Architect Richard Bosch, AIA and a CM consultant.  Through the client’s commitment to research, analysis, and insisting upon the services of  experienced Engineers and Architects, many unique opportunities were discovered while substantial costs and risks were avoided. 

Step 1: Piping Condition Assessment

The purpose of the piping condition assessment was to determine without doubt, the actual condition of the existing piping system.  This knowledge would drive many decisions such as schedule, material, priorities, proposals, and techniques that could or could not be used when performing the repipe.  A typical Coengineers piping condition assessment may be referenced here (Assessment report)

Step 2: Material Selection Process

The HOA board was especially concerned about various piping materials and requested a review of Epoxy Liner, Copper, and various plastic products.  Epoxy was rejected (Epoxy Report), Copper was compared with alternates such as PEX and Polypropylene (Tech Study Report)

Step 3: Contractor RFI/RFP process

RFI process sought to find the most qualified mechanical services firms who would be willing to undertake such a project.  For each, we requested a rough estimate for performing the job in each of three materials; Copper, Copper/PEX, and Polypropylene. The Board selected Polypropylene. The RFI approached a dozen qualified firms in the Portland Area. 

Step 4: Contractor RFP process

Of the five top candidates from the RFI process, three were selected for the RFP process. Polypropylene (PP-R) was somewhat unfamiliar for many contractors and represented many unknowns.  Ultimately, the board selected McKinstry, Inc due to their excellent reputation and prior experience in PP-R.  The polypropylene piping material and complete plumbing system was supplied by Aquatherm.  

Step 6: Detailed Statement of Work  

As the RFP prices and ideas came in, it was obvious that a different approach to re-piping the building was needed – it would not be possible to rely on the plumbers for a solution. We consulted with Duane Tilden, P. Eng., a member of the Coengineers network, who has re-piped over 40 structures of this type.  His recommendation, based on a similar re-pipe he had performed in Canada, was to send the main risers up through the garbage disposal closet   This suggestion was a perfect fit for the Harrison West Project and ultimately defined the strategy for this re-pipe.  

Step 7: Re-piping The Harrison West.   

Harrison West Case Study

Renderings by Richard Bosch Architecture, Portland OR

Harrison West Case Study

Plan Schematic (click to enlarge) c. Richard Bosch, AIA


The Harrison West Condominium Association received a ultra-clean, high reliability potable water system using non-metallic components.  This project was unique in many important technical areas and will long be considered a landmark re-pipe in the engineering profession.  The price of the project is scheduled to compete with copper while the carbon footprint (over copper mining, smelting, transportation, and recycling) is dramatically lower.  This unique high-profile re-pipe will have a direct and positive impact on home values for this community.

Installation Photos (c. Richard Bosch Architecture, AIA) click to enlarge:



Harrison West Case Study

Risers pass through refuse chute closet void

Harrison West Case Study

Ceiling loop at only 3 hallway floors













Harrison West Case Study

McKinstry provides excellent cleanliness and PM support

Harrison West Case Study

Wall Drops; note service valves