McKinney Green Building 
by Curt Parde 

The McKinney Green Building Project Overview  

HDR is working with West World Management to incorporate sustainable elements from all categories of the USGBC LEED program into its McKinney Green Building .  Since the McKinney Green Building is a speculative office building, HDR and the owner focused on incorporating features that contribute to high energy efficiency and excellent indoor environmental quality.  Concentrating on these items will help reduce long-term operating costs and provide high-quality space for future tenants.  The building, at 4500 West Eldorado Parkway in McKinney , Texas , is located on a three-acre parcel of land adjacent to a large multi-family apartment complex.

This article explains the design team’s process during the development of this exciting project, now under construction.  

Pre-Planning, Space Programming

Proper planning during the early phase of a project is critical to success.  The HDR project team and the owner developed a space program and project budget.  During this pre-planning phase, the team found that the owner was interested in developing a significant sustainable project equal to a LEED platinum building.  Some of the most significant items the owner focused on were in the Energy and Atmosphere credit category.  With the goal of reducing energy consumption in the building by over 60 percent and incorporating on-site energy generation into the project, the team discussed the budget needed to support these sustainable commitments.   

LEED Workshops

During the pre-planning and space programming phase, the team also held Sustainable Design Workshops.  For two days, we discussed sustainable design features focusing on the five basic LEED categories.  We developed a list of ways to incorporate sustainable design elements into the office building and discussed the practicality of these items.   

An example was the concept of operable windows.  These can be an important element in getting fresh air into an office building, thus improving indoor air quality.  However, with building security issues, maintenance, and concerns with HVAC system control, the team decided this was not an option for this project.  

Design Phase

Early on in the design phase, the team worked closely with a day-lighting consultant to discuss building orientation, fenestration, shading opportunities, building layout and floor plate depth.   We also developed site options, including different building orientations, parking layout options and site access.  The owner wanted a minimum of about 60,000 square feet of office space on the three-acre site, so efficient use of the site for parking, landscaping and drainage were important.  Parking decks and underground parking were discussed.  In the end, the most efficient way to orient and develop the site was with a simple rectangular floor plate centered on the site with parking around the perimeter.  

The building floor plate was developed to accommodate an open-office arrangement on the building’s three tenant floors.  The shallow building depth, higher ceiling spaces and many windows allow for more natural daylight.  The non-occupied spaces, including mechanical rooms, electrical rooms, telephone and data rooms, elevators and stairs, are located in the building core in the center of the floor plate, which provides the most efficient use of space and distribution of systems to different floors.  

During the design phase, the team investigated the efficiencies and long-term savings of different HVAC systems using energy modeling.  The modeling was based around ASHRAE standards.  The different HVAC systems modeled included “solar hot water absorbers,” “geo-thermal heat pump” and high efficiency standard systems.  The initial design for the building used the solar hot water absorber system.  Due to complexity and cost of this system, it was replaced with a geo-thermal heat pump system.  

Additionally, the team decided to use under-floor air distribution in the project.  The lighting system selected for the tenant spaces will have occupancy sensors and daylight sensors, enabling the lights to shut down automatically when not needed.  The R-Value for insulation in the walls of the building was increased to an R-30.  The R-Value for insulation on the roof was increased to an R-50.  Highly efficient low-e glazing is being used.  Also, exterior sun shading devices will shade much of the glazing during the day. 

All of these features contribute to the projected decrease in energy use by this building of approximately 62 percent.

Commissioning

During the design phase, a third party commissioning agent was hired to give input on design decisions and help make the building as energy efficient as possible.  The commissioning agent reviewed the documents at different phases to ensure functionality of the building systems design.  The agent will also make sure the building systems operate at optimum capacity when complete.  

General Contractor, Construction Manager Selection and Value Engineering

Because this project will incorporate many sustainable design ideas, the project team welcomed additional reviews of the design documents.  The general contractor and construction manager helped with the reviews, and also selected quality MEP sub-contractors for the project.  This is important as the facility will utilize the latest in technology and energy-efficient equipment.  

The value engineering process provided several opportunities to re-evaluate building materials and systems, including:

  • Changing the elevator to a non-hydraulic machine that does not use hydraulic fluids and uses approximately 50 percent less energy than the previously selected standard hydraulic elevator.

  • As a cost savings measure, the limestone originally specified for the exterior façade was replaced with a locally-manufactured brick. 

  • After visiting other under-floor air installations, the team made a few adjustments to the system so it could provide more flexibility to the owner.

  • The support system for the photo-voltaic panels was revised so it sits on top of the roof, not penetrating the roof membrane at each support, to help provide a better overall roof installation.

  • Some of the specified light fixtures were changed out, offering savings to the owner while still providing optimum energy efficiency. 

LEED Pre-Construction Conference

Before construction started, we held a LEED pre-construction conference to address questions from the owner, the entire design and construction team and subcontractors, and the commissioning agent.  At this meeting, we reviewed the LEED credits the project was targeting so the entire team had an understanding of the goals for the project.  We also discussed the process for LEED submittals, what information would be required, the IAQ plan, the Construction Waste Management Plan requirements, the Recycled and Regional materials documentation requirements, VOC Content, and how to manage all of this information in support of the final LEED submittal.  

LEED Core & Shell

When this project was started in 2002, the LEED program available for the project was LEED NC , which is what the project was registered under.  The LEED Core & Shell Pilot Program has since become available so we changed the registration of the project to this program.  While still in the pilot phase, this new program is designed specifically for speculative office buildings, like the McKinney Green Building , and it enables the owner to receive a pre-certification for the building, which allows them to market it as a LEED project. This is viewed positively by many prospective tenants.  The McKinney Green Building recently received a platinum level pre-certification for design.  

Wrap-up

The project has been under construction for almost six months, and is scheduled to be complete in April 2006.  Upcoming project milestones on this sustainable building include:

  • Structural steel is scheduled to be complete the end of September.

  • The geo-thermal wells being drilled on the site will be complete by mid-September.

  • The storm water retention system installation will begin in September.

  • MEP equipment will begin arriving at the site in mid-September.

 

Curt Parde is a LEED AP and principal at HDR.  He works from HDR’s Dallas office and has worked with the owner on the McKinney Green Building for the past three years. For additional information regarding this article, please contact Curt Parde at curt.parde@hdrinc.com. All comments are the sole responsibility of the author.