Data center shells may be procured separately from fit-out to enable overlapping design and construction. Any schedule benefit depends on coordinated package boundaries, design information and handover requirements. Scope gaps can arise when the parties make different assumptions about what the shell includes.
Use the checklist below to define the shell package before pricing. Requirements vary by owner, design and project; confirm them with the design team and record them in the procurement and contract documents.
01Define what “shell” means on this project
Shell terminology is not standardized. Owners, developers and contractors use terms like cold shell, warm shell and powered shell differently. Write down what the shell package includes rather than relying on a label.
- A written scope description and responsibility matrix for the shell package
- What is included in the building, on the site and in the utilities to the building
- What condition the building must be in at handover
- Which work belongs to the fit-out contractor, owner-direct contractors or the owner
02Site, foundations and slab
Slab and foundation decisions are hard to change once the shell is built. Settle the requirements that fit-out will depend on.
- Slab design loads, flatness and finish requirements from the design team
- Embedded items, blockouts and sleeves needed for future work
- Housekeeping pads and equipment foundations: in the shell package or by others
- Below-slab utilities and future penetrations, and how they will be located
03Structure and enclosure
Define structural capacity for agreed equipment loads, locations and attachment requirements, including applicable construction and rigging loads. Record provisional assumptions; later equipment changes require review by the responsible structural designer.
- Design loads for roof-mounted or suspended equipment and systems, from the design team
- Structural provisions for future supports, openings and penetrations
- Wall openings, louvers and doors for equipment delivery and air paths
- Criteria for the building to be considered weather-tight
- Approval responsibility for later coring, cutting, penetrations and attachments, including verification of concealed services and structural constraints
04Roofing and envelope
Fit-out work often penetrates the roof and walls after the shell is complete. Plan for it so warranties stay valid.
- Roof system and warranty requirements
- Who is allowed to penetrate the roof and envelope after handover, and how penetrations are made and inspected
- Provisions for future penetrations included in the shell
- Envelope performance requirements specified by the design team
05Utilities to the building
Every utility needs a defined point of connection between the shell package and the work that follows.
- Electrical service provisions, duct banks and points of connection
- Domestic water, fire water, sanitary sewer and storm connections
- Telecommunications entries and pathways
- Which utility work is by the utility, the owner, the shell contractor or the fit-out contractor
06Fire protection and life safety
Requirements for the shell depend on the authority having jurisdiction and the intended use. Confirm them with the design team early.
- Fire protection and alarm systems required for the shell, and for any interim use
- Temporary versus permanent systems at handover
- Inspections and approvals required before handover
07Provisions for fit-out
Small provisions in the shell can save large rework later.
- Sleeves, blockouts and embedded conduit for future systems
- Access routes and openings for large equipment deliveries
- Laydown, staging and site logistics available to the fit-out contractor
- Temporary power, water and facilities available after handover
08Exclusions
A clear exclusions list protects the schedule and the budget as much as the scope description does.
- Work excluded from the shell package, listed explicitly
- Allowances and assumptions used in pricing
- Owner-furnished items and owner-direct contracts that interface with the shell
09Handover to fit-out
The handover is a milestone with criteria, not a date on the schedule.
- Condition of the building and site at handover
- Inspections, approvals and documentation required at handover
- Warranties, record drawings and responsibility for damage after handover
- How the shell and fit-out contractors coordinate if their work overlaps