How to use IPD for design-bid-build success
By engaging all the players in a building’s design or retrofit, integrated project delivery (IPD) can ensure the project runs smoothly.
- Know the basics of an integrated project delivery (IPD) philosophy, and when it can best be applied.
- Develop an approach to completing an IPD building project.
- Learn from an example of how to best implement IPD in a building retrofit.
Since the turn of the 21st century, integrated project delivery (IPD) has been developed as both a project delivery method and a philosophy in response to a desire to reduce waste, improve productivity, embrace technological evolution, and support increasing owner demands for value. IPD as a delivery method was developed in the 1990s and patented in 2000. It involves defined collaboration between all project stakeholders—including the owner, design team, and contractor—to ensure that best practices are leveraged at all phases of a building project through a multiparty contract. Lower project costs and higher-quality work are incentivized with this method, along with consistent communication and transparency among all stakeholders. The open nature of the process balances the goals of each stakeholder from the beginning of a project.
An engineer’s role in the delivery process is critically important due to the increasing cost of technical systems, their level of complexity, and the increasing pursuit of high-performance outcomes for indoor environment quality and resource use.
IPD is a more comprehensive version of the design-build procurement model. Both design-build and IPD include a single design-builder entity. IPD, however, further defines specific roles for the owner and specific responsibilities for decision making. IPD holds all parties involved to a shared and transparent risk-reward structure. Typically, a project that does not meet prescribed quality metrics results in a shared loss of financial success.
IPD was developed in response to challenges with design-bid-build (DBB) delivery, which is still considered the most widely used project delivery method. In the DBB model, the owner engages in two separate contracts: one with a design team and the other with a general contractor. This split system amplifies the potential for adversarial team relationships, resulting in potential budget-control issues for the owner, as constructability or quality issues come into play. A design team does not benefit from constructability input during the design phase, and a contractor does not benefit from the project knowledge developed through design team interaction with the owner. Once a project enters construction, the design team’s involvement reduces, increasing the risk for miscommunication or misinterpretation of design intent.
Leveraging IPD principles to DBB
A Construction Management Association of America study from 2012 indicates that only 1% of projects use IPD as a delivery method. Yet, it is possible to apply an IPD philosophy to any project, even if there is no formal multiparty contract. This can be referred to as IPD lite, IPD-ish, hybrid IPD, or technology-enhanced collaboration.
IPD-lite projects may incorporate the following components described by the Associated General Contractors of America:
- Fiscal transparency between key participants.
- Early involvement of key participants.
- Intensified design.
- Jointly developed project target criteria.
- Collaborative decision making.
- Mutual respect and trust.
- Willingness to collaborate.
- Open communication.
- Use of building information modeling (BIM).
- Use of lean principles.
- Team colocation.
This article focuses on aspects of these elements that are more readily approached in a DBB-delivery framework, but can result in improved project outcomes.
One of the main challenges with DBB is that a contractor is not brought on board until after design is complete. The owner may choose to still bring on a contractor for preconstruction support or identify a project manager that has significant construction experience to assist the design team with lessons learned from prior projects. Projects benefit from early partnering sessions to identify a vision for the project, risk factors, and a communication strategy.
It is critical that as many stakeholders as possible be identified early on and that the natural hierarchy in any organization does not become a barrier to smooth and transparent information flow. Often, facility managers and their operations teams will be integrated into projects relatively late. Their feedback is critical to the long-term success of a building’s operation. An owner’s organization may have final decision makers that cannot participate in a project from day to day; it is critical to determine a series of meetings on a monthly or quarterly basis to keep them informed of critical milestones where their input is needed.
A significant amount of focus has been given to the owner’s project requirements (OPR) as a component of the commissioning process. This document should capture broad project goals and also establish a prioritization to those goals, such as schedule, budget, and quality considerations, so that these can be evaluated through the natural course of a project. These goals serve as a roadmap to keep an entire project team on point.
The OPR document is translated into a design based on a team’s technical expertise and interpretation of a significant number of factors, such as codes and standards, assumptions for occupancy and equipment, or even the project budget. It is important to clearly document these inputs in a basis of design (BOD) document. This should be presented proactively to other design team members and then back to the owner team. If a key design assumption is not fully understood by the owner, it can cause the project to go off course.
At the end of each primary design phase, the design team should present to the owner an overview of their approach as well as risk factors or assumptions. To allow knowledge transfer to occur, the owner should describe special design features in solicitation documents for contractor selection and have the design team participate in prebid activities. Bidding contractors often do not have the benefit of months or years of history with a project and may need additional context beyond what is shown on plans and in specifications.
Once a contractor is selected, the owner, design team, and contractor should have a partnering session to review project goals and provide an opportunity for both the owner and design team to present key project considerations. If the building has a building automation system (BAS), the controls integrator should be brought into discussions with the team as early as possible.
The key takeaway is the importance of sharing, documenting, and building upon subject matter expertise at key milestones of a project. From a consulting engineer’s perspective, establishing strong, collaborative, and trusting relationships early is equally as important as technical know-how.
IPD in existing-building modernization
The IPD mindset is useful when working on a variety of project types, but it is particularly relevant for existing-building modernization projects. It is typical for unforeseen conditions to arise during construction as older systems are removed from an existing building. These conditions must be addressed by a cohesive team that is prepared to communicate openly to find and employ the best solutions.
BIM enhances the transfer of information between stakeholders in a virtual environment. While BIM is often equated to the use of 3-D modeling software, the higher-level goal is to share information across a multidisciplinary team; not only is the information useful during the entire duration of a project’s lifecycle, but also during the building’s lifecycle, which includes post-occupancy. Virtual and augmented reality models are now increasingly being linked within a BIM process to further enhance collaboration and reduce the risk of miscommunication, coordination issues, and project rework.
A data-rich process may allow more real-time quantification of materials for cost modeling, analysis of building systems for their impact on energy and water use, or the visualization of sequencing for complex phases of construction involving multiple subcontractors. Often, work within existing or historic buildings is constrained by spatial or structural limitations, where each building trade must install work in a certain sequence to maintain code-required head heights (6 ft 8 in. is typical) or proper access for equipment maintenance, like filter changes.
Putting IPD into practice
An IPD mindset is particularly useful for work on historic buildings listed on the National Register of Historic Places, which follows the Secretary of the Interior’s Standards for Rehabilitation. These standards consist of 10 guiding principles for historic-building projects. Significant tax and grant incentives available through federal and state programs are contingent on successful implementation of these standards.
The Renwick Gallery of the Smithsonian American Art Museum in Washington, D.C., recently went through a major modernization. This historic institution was completed in the 1860s, listed on the National Register of Historic Places in 1969, and is considered the first purpose-built art museum in the United States. The building was originally designed by James Renwick Jr., the architect of the Smithsonian’s “Castle” and St. Patrick’s Cathedral in New York City. It is often referred to as the American Louvre, with many similarities to the Second Empire Style Tuileries Gallery of the Louvre in France. The Renwick Gallery was at risk of being demolished in the 1960s to make room for a new government facility. In the early 1970s, first lady Jacqueline Kennedy led a successful campaign to bring new stewardship to the facility, including a modernization to restore the building’s use as a museum.
Fast-forward to 2011 and a combination of aging infrastructure, new demands for exhibit flexibility, and updated building codes necessitated a major renovation. Funding for the project was from both private and public sources. As such, visible improvements that energized the owner’s donor base had to be balanced against equally important, but less visible, building system upgrades. The project team was additionally driven by two guiding principles from the Secretary of the Interior’s standards:
- A property shall be used for its historic purpose or be placed in a new use that requires minimal change to the defining characteristics of the building and its site and environment.
- The historic character of a property shall be retained and preserved. The removal of historic materials or alteration of features and spaces that characterize the property shall be avoided.
While DBB delivery was selected by the Smithsonian Institution for the project, several elements of an IPD workflow were integrated. The design process began with a series of partnering meetings to prioritize goals and develop greater connections between team members. These meetings included facility management staff and owner representatives that had recently completed other major construction projects. Creating connections was essential to building trust and sharing ideas among team members. This proved useful for collaboratively developing solutions during design, construction, and commissioning. The goals for the project were set forth in the OPR document, which was developed in the first 60 days of the project and continually updated. These requirements kept the team on track with the owner’s goals.
The design team gathered existing building documentation through interviews, multiple onsite surveys, and a review of historical records dating back to the mid-1800s, which included drawings, utility bills, and environmental-control trends. The building systems had not been updated since the previous renovation in the 1970s and had significantly exceeded traditional service life. Many systems were difficult to access for maintenance and repair or not up to current codes, solidifying the need for comprehensive upgrades.
The history of the building was closely studied, with existing pathways and spaces for building systems noted and included in early design models. More than 30 different vertical pathways exist in the building, created within the historic fabric. Yet virtually no horizontal pathways are available for ductwork on the main floors, due to the inherent architectural characteristics of primary gallery spaces. These spatial limitations demanded collaboration among team members. This led to a strong focus on reduced cooling-load demand, facility operations input, risk reduction for art, and overall space usability.
The most significant achievement to come from an IPD mindset was the avoidance of raising the building’s roof height by 10 ft. The original master plan for the building included accommodating attic air handling unit (AHU) equipment by raising the roof’s height. This plan, however, was not compatible with the historic preservation requirements set forth for the building, and it would have been a costly design feature.
The team developed the following approach:
Clear criteria: For museum projects, the required environmental-control envelope for temperature and humidity needs to be set prior to major design iterations. For the Renwick Gallery, conditions were discussed in the first 30 days of the project and held through the remainder of the project. The overall project construction budget was also firmly set by the owner at an early phase.
Cooling-load reduction: The Smithsonian Institution had previously participated in U.S. Department of Energy research on the use of LED lighting for gallery lighting. In 2012, LED technology still did not have the color stability, color temperature, and beam control required for a fine art museum. The design team’s integrated lighting designer, electrical team, owner’s lighting designer, and a lighting manufacturer collaborated to develop an entirely new line of LED sources suitable for the project. The reduction of lighting-power density from 5 W/sq ft to less than 1 W/sq ft, while not compromising lighting quality, allowed for a significant reduction in overall building airflow, enabling an improved fit of systems within the building.
Maintenance focus: Temperature and humidity control was a challenge prior to modernization due to aging infrastructure that was difficult to access for maintenance. The design team worked closely with the facility manager, field technicians, and controls specialists to understand day-to-day challenges with system operation, as well as physical-space requirements for access to valves, motors, filters, and other components that frequently need service. This process shaped a system approach where all equipment can now be serviced safely and efficiently. For example, critical-zone variable air volume (VAV) boxes are grouped in three areas, rather than spread out throughout the building. Fan arrays with redundant variable frequency drives allow air circulation, even if individual motors require maintenance.
Acoustics focus: The Renwick Gallery is the primary venue within the Smithsonian Institution’s building portfolio for chamber music and lectures. The design team included acoustics engineers that provided very early feedback on targets for sound generation from equipment and other requirements that might have a significant spatial impact on ductwork configuration.
Risk-reduction focus: Hydronic, storm, and sanitary piping previously ran over collection spaces. Through careful team coordination, owner input, and the use of building-science analysis, piping for these systems now run in noncollection zones. A key element was the conversion of hydronic baseboard heating into low-grade electric heating sized only to reduce condensation risk at windows. Thirty-four windows were upgraded with an improved system with more historic profiling, ultraviolet (UV) control, security control, and enhanced thermal characteristics.
Benefits of IPD at Renwick Gallery
Owner structure: The Smithsonian Institution has an extensive building portfolio, which includes many complex structures that have gone through renovations in the past decade. This experience allowed the owner to set reasonable contingencies for construction and provide a decision-making structure that was efficient. This is one example of what an owner can do in a healthy project, which can be contractually required in a formal IPD arrangement. The project was one of the first to use a full virtual-construction model, which has now become a requirement for future modernization projects for the Smithsonian Institute, regardless of delivery model.
Condensate system: The project incorporated an HVAC condensate-reclamation system, which was initially not understood by the contractor during development of the virtual-construction model. This system required a less-traditional piping configuration and was more appropriate for the Renwick Gallery’s specific needs. Regular dialogue allowed the intent of this system to be clarified before an incorrect interpretation of the system was installed.
Basement coordination and space perception: The basement level of the Renwick has limited head height, starting with a 7 ft 10 in. distance from the floor to the bottom of structure and leaving approximately 1 ft for ductwork, conduit, piping, lighting, and other building systems. This demanded extensive dialogue among the design and construction teams to develop an optimized combination of duct construction, duct-insulation type, hanger locations, and fittings to keep a clearance of 6 ft 8 in. in spaces. While dialogue on constructability would have benefitted the team during design, these issues were tackled through the virtual model and by leveraging subject matter expertise from appropriate team members at the right time. One lesson learned is that even a 3-D representative of a space may still be inadequate for stakeholders not traditionally engaged in a major building project. Augmented reality would allow a team to visualize new systems against the backdrop of existing architecture.
Manufacturer engagement: There was a significant contrast in the team’s experience with two systems on the project: gallery lighting and an existing modular chiller. Components of the chiller plant were installed in a replacement project prior to the major modernization. The vendor had very poor performance on the project, with slow, incomplete, and inconsistent responses to design, construction, and operations feedback. This is one of the biggest challenges that faces the building industry. One can select a high-performance team, but because of how products are procured, there can be a lack of consistent engagement from a vendor.
For this project, the gallery lighting manufacturer invested additional time in research and development to create a product that met a whole series of demanding attributes. The manufacturer realized that strong performance would allow for future benefits, including the ability to use the product in retail and hospitality sectors. An IPD workflow should seek to identify critical equipment types and then vet manufacturers not only based on price, but also on past service performance. This remains a challenge in the industry, as final pricing for equipment is generally only provided to contractors and not to design team members.
One of the earliest steps during construction was a multiphase process of laser scanning both the exterior and interior volumes. The design team did not have the benefit of full visibility to interior elements during design, as the building remained fully operational to the public. The laser-scanning process allowed development of a high-fidelity existing spatial-condition model of the building that created a shell for development of a multidiscipline virtual-construction model.
The team’s overall approach was not only compatible with historic-building mandates and the budget, but it also was an efficient solution, reducing energy consumption from prerenovation values by 50%, with an energy-use intensity (EUI) from 199 down to 102 kBtu/year-gross sq ft. None of these achievements would have been possible without the creative discussions held between the owner, design team, and contractor.
The benefits of an IPD mindset are illustrated with several examples from the Renwick Gallery renovation:
The Renwick Gallery reopened in November 2015 with an initial exhibit titled “Wonder.” After opening, the gallery quickly exceeded its previous annual visitation average, seeing more than 500,000 visitors and nearly 180 million social media impressions in its first 6 months. The reopening has engaged new audiences, especially millennials and young professionals, as reflected in increased social media activity. Once considered a "hidden gem," the newly reopened space has become a true destination for art lovers and visitors across all demographics who are passionately excited about its exhibitions, its history, and its importance for Washington, D.C., and the nation. The success of the project would not have been possible without the use of an IPD mindset.
Roger Chang is a principal and an energy and engineering leader at DLR Group. With more than 15 years of experience designing, Chang envisions the continued use of technology in all facets of design through construction and operations.