The Leaflet Article
Professional engineering services in a design-build delivery model
Changes in the healthcare industry are increasing the incidence of design-build projects. This article explains how to best utilize professional engineering services within this delivery model to obtain maximum benefit for the owner and user.
In response to the Affordable Care Act (ACA), healthcare providers are shifting their focus to outpatient services. As a result, significant investment exists in medical office building and clinic construction and renovation projects.
A traditional delivery method for the engineering design of MOB and clinic projects is the “design/build” approach. As part of this approach, an engineering design firm is retained to select the MEPT systems and develop concepts, but is not retained as the engineer-of-record to complete detailed construction documents. In doing so, the expense of full design services is eliminated. While the expertise of the engineer is retained as the building is conceptualized, the balance of design is often completed by the installing sub-contractors.
While the design-build model should continue to be successful for owners, there exists a need for clarity regarding the scope of services provided by engineering design firms. Expectations of the engineer’s involvement, or lack thereof, often differ between the owner, builder, architect, and engineer. Clearly defining those expectations will have several benefits:
- It will allow the engineering proposals to be evaluated on an “apples-to-apples” basis. Without clearly defining the expectations, engineering proposals and their subsequent fee arrangements can vary widely. It is in the owner’s best interest to clearly define their expectations.
- It will define the deliverables required of the engineering firm. Without clearly defining those deliverables, drawings and specifications produced by the engineering firm can vary in detail and clarity.
- It will ensure a minimum level of continued engineering involvement through completion of design and construction. Without clearly defining that involvement, the engineering firm may not stay engaged throughout the entire process. This is especially important if the project has LEED or energy efficiency goals that cannot be attained if deviations are taken by the sub-contractor as the design is completed.
The following provisions are recommended for the engineering scope associated with each phase:
SCHEMATIC DESIGN AND DESIGN DEVELOPMENT PHASE SERVICES
1. Schematic Design:
a. Schematic-level drawings and narrative defining space needs, conceptual layout, and system selection
2. Design Development:
a. Flow/one-line diagrams, control sequences, and system descriptions for all major systems.
b. Equipment layouts in mechanical, electrical, and telecom rooms.
c. Main utility routing and coordination, including shafts and horizontal distribution mains.
d. Outline specifications and material lists describing product quality and owner preferences.
e. Sizing criteria for utilities, such as ductwork, piping, etc.
f. Selection and specifications for plumbing fixtures
g. Light fixture selection, layout, and control requirements
h. Fire protection requirements
i. Medical gas requirements, if any
j. Guidelines for layout and wiring of technology and power receptacles
k. Guidelines for fire alarm, security, nurse call systems, etc.
CONSTRUCTION DOCUMENT (CD) PHASE SERVICES
1. Peer Review of 100% CD Drawings
2. Assistance as needed with questions related to design concepts or user group meetings
BIDDING/NEGOTIATION PHASE SERVICES
1. Assistance as needed with questions related to design concepts or user group meetings
2. Assistance with bid evaluation
CONSTRUCTION PHASE SERVICES
One job-site observation during construction, plus one final job-site observation at the end of the construction period
LEED DOCUMENTATION SERVICES (IF APPLICABLE)
Many owners strive for LEED certification. When doing so, it is important to define the engineering consultant’s role in achieving that goal.
Since the scope of documentation ultimately depends on which points are pursued, a sample scorecard should be utilized to determine which points would be required to lead or assist with the documentation. An option to adjust fees as the LEED plan is finalized would be advantageous for all parties.
Assumptions related to LEED:
1. The primary LEED consultant will be identified by the owner. It could be the engineering consultant, but does not need to be. Duties of the primary LEED consultant would include coordinating, monitoring, tracking, and collecting the information and documentation needed for submittal to the United States Green Building Council (USGBC). If not the primary LEED consultant, the engineering consultant would be responsible only for uploading and managing information related to credits assigned.
2. Commissioning services (best provided by the engineering consultant) will be provided separately from LEED documentation services.
3. Energy modeling (best provided by the engineering consultant) will be provided separately from LEED documentation services.
ENERGY MODELING LEED SERVICES (IF APPLICABLE)
Energy modeling is required to document prerequisites and LEED credits, with most work required for EAp2 and EAc1 to demonstrate code compliance and energy savings over a code baseline. This modeling will include energy usage and cost calculations related to energy-using systems. An energy savings goal will be set early in the project that is consistent with the proposed building envelope and conceptual systems and the project budget.
The scope of energy modeling should include:
1. Schematic Design:
a. Develop a preliminary energy consumption model of the baseline building.
b. Develop a preliminary energy consumption model of the proposed building incorporating preliminary energy saving design concepts to determine approximate energy savings and possible LEED credits.
c. Analyze three major system types to confirm overall direction of the project early on.
2. Design Development:
a. Perform an additional iteration of the baseline and proposed building energy models based on the design development documents.
b. Analyze three energy efficiency measures relating to mechanical, electrical, or envelope systems as design develops. These will be identified by the design team and owner.
c. Energy analysis results will be communicated to the team in a brief report or presentation. It is anticipated the design team will make decisions based on these results and incorporate the decisions into the final design.
3. Construction Documents:
a. Develop a final energy consumption model of the baseline and proposed buildings based on the 100% construction documents to determine probable LEED credits.
b. Complete required LEED online documentation and submittal information.
c. Respond to one credit audit from the GBCI related to EAp2 and EAc1. Further correspondence or appeals will be considered additional services.
FUNDAMENTAL COMMISSIONING SERVICES (IF APPLICABLE)
LEED certification requires fundamental commissioning of the building energy systems. The scope of fundamental commissioning would be as follows:
1. Commission the following HVAC, temperature control, and electrical systems:
a. Heating, ventilating, air conditioning, and refrigeration systems
b. Direct digital controls systems and integration to equipment controls
c. Lighting controls
d. Domestic water heating systems
2. Design Documents:
a. Assist with development of Owner’s Project Requirements (OPR) Document, which details the owner's expectations and performance requirements for the project. The owner will be the author of the document.
b. Review and comment on the Basis of Design (BOD) document. This document will contain not only the system design, but also the system concept to allow future operators to understand why the systems were designed the way they were. The BOD is developed by the design team in response to the OPR and other program requirements.
c. These documents will be updated and revised during design and construction by the authors when appropriate.
3. Commissioning Plan, Schedule, Specifications, and Meetings:
a. Develop commissioning plan, which will include:
1) Identification of major tasks and team member responsibilities
2) Detail of the required interaction of contractors and the owner in the commissioning process
3) Description of the scope of the contractor’s work during commissioning
b. Develop commissioning specifications for inclusion into the contract documents
4. Verify installation and performance of commissioned systems:
a. Issue pre-functional checklists to contractors to be used in documenting equipment and component installation.
b. Review completed pre-functional checklists and visually spot check select installations.
c. Develop functional test procedures, based on contract documents and approved submittals.
d. Witness functional performance testing performed by the contractor. Testing shall encompass the systems described above, and include each process in the sequence of operations, including startup, shutdown, capacity modulation, emergency and failure modes, alarms and interlocks to other equipment.
e. Conduct seasonal testing as required, limited to those operations, such as chiller staging, that must be performed during approximate design conditions.
a. Maintain a log of active commissioning items, including the status of each item and dates when status changed or when item(s) are closed.
b. Issue a final binder, including documentation.
c. Upload files and documents to LEED online as required during the certification process.
ENHANCED COMMISSIONING SERVICES (IF APPLICABLE)
LEED awards additional points for enhancing the commissioning process. The engineering consultant can expand fundamental commissioning services to fulfill this credit. In addition to the fundamental commissioning listed above, the scope of work for enhanced commissioning includes:
1. One peer design review prior to 50% design:
a. Develop tracking log of comments and suggestions.
b. Include one design review meeting with the design team and owner to review comments.
c. Review final construction drawings for inclusion of peer review comments.
d. Issue a final report of the peer review process.
2. Review of selected energy system submittals and shop drawings for compliance with the OPR and BOD documents. Comments will be forwarded to the owner and design team.
3. Development of systems manual for future operating staff use to understand and optimally operate the building systems
4. Proper owner training
5. Ten-month warranty review
1. The owner/user has input into the design and systems selection along with approval of all major equipment.
2. Engineers provide designs to fit the needs of the building and not systems or equipment represented by sub-contractors.
3. Documents provided by the engineer are biddable by the sub-contractors. This ensures competitive pricing on an apples-to-apples basis.
4. Bid pricing by the sub-contractors in relationship to conventional design-build pricing will save between 5% and 10% of costs. This can offset most upfront design costs from the engineer.
5. Peer review ensures that the final design from the contractor meets the design intent without cost or equipment deviations intended to save the sub-contractor money.
6. Final job-site observation ensures that the sub-contractors have completed their work in conformance with the construction documents.
This combination of expertise and talents by both the engineer and sub-contractor provide the optimum project value for healthcare construction delivered in a design-build delivery model.
About the authors: David Smith, PE, EDAC, LSS, is a principal and the national director of healthcare for KJWW Engineering Consultants. Derek Schnabel, PE, LEED AP, is a senior manager at KJWW. For more information, visit kjww.com.