Timelines, Cost, and Process: Greenfield vs. Adaptive Reuse Data Center Construction

Adaptive reuse, the strategic repurposing of existing buildings and infrastructure, offers a compelling solution for developing data centers in the AI era. Modern AI workloads depend on low-latency, high-performance networks to support real-time inference, which usually makes urban locations more desirable than traditional, large rural campuses for user-facing AI deployments. AI-optimized data centers require liquid cooling systems, meaning operators must either construct new facilities designed for these demands or adapt existing buildings to support advanced cooling infrastructure.

When executed well, adaptive reuse can significantly accelerate time-to-market and deliver meaningful cost savings. It is also a more sustainable alternative to new construction, reducing waste from demolition, emissions from heavy equipment, and the need for new steel and concrete. With experienced data center developers and operators, existing facilities can be engineered to meet both current and future computing requirements.

Although greenfield data centers (purpose-built on undeveloped land) and adapted facilities (brownfield or retrofit projects) follow similar construction phases, the scope, complexity, and challenges within each phase differ substantially.

Greenfield vs. Adaptive Reuse: Pros and Cons

There are always exceptions, but generally adaptive reuse projects are going to have a shorter timeline to completion and require fewer resources. However, adaptive reuse projects can be more restricted but may offer more flexibility when it comes to location.

The Assessment Phase

The assessment phase is critical for both greenfield and brownfield data center development, but evaluating brownfield sites is often more complex and demands broader expertise. Developers must begin by understanding a client’s IT requirements, projected demand, and security and redundancy needs. Only with this information can they determine whether a potential site can support the required infrastructure.

For greenfield development, assessments focus on the availability (or future availability) of power, fiber, and water, along with geological surveys and hazard screenings. Developers must also secure a Power Purchase Agreement for new utility power and determine how that power will be delivered. In many cases, they may need to help fund upgrades or expansions to nearby substations. Given today’s constrained utility environment, securing new power can take several years.

Adaptive reuse projects must account for all the above considerations but add another layer of scrutiny: the existing building’s structural capacity, layout, HVAC systems, security systems, plumbing, electrical infrastructure, and maintenance history. The more known about a building up front, the more issues can be avoided, or proactively mitigated later on. One key advantage is that many existing facilities already have stranded power that has been allocated but is not being consumed. However, developers still need to conduct studies and negotiate with utility providers to secure additional power for future growth.

The Permitting and Design Phase

Both adaptive reuse and greenfield projects require building and environmental permits. Although existing buildings may already hold zoning approvals, additional permits may be necessary for water withdrawal and discharge, noise, air quality, waste management, and other environmental impacts. Zoning changes may also be required if the property is not already entitled for data center use. Generally, greenfield developments experience longer permitting timelines.

The design phase is typically more complex for greenfield projects, which require a full architectural and engineering program, from below-slab utilities to the structural frame to the roof. Adaptive reuse shortens this process because the core and shell already exist; most design work focuses on reconfiguring white space and updating power and cooling systems. Once design is approved and all permits are in place, the project can advance to construction or renovation.

Renovation or Construction Phase

Greenfield construction starts below ground, installing fiber routes, water systems, and power infrastructure, along with pylons if required by the foundation design. After this, work progresses to the building’s core and shell. These early stages alone typically require at least 12 months.

Adaptive reuse bypasses the need for foundational and structural work. Renovation begins with removing outdated mechanical equipment and installing new piping, conduits, and mechanical systems. The project team then adapts or builds new white floor space according to the client’s specifications. Once all new equipment is in place, the project moves into testing and commissioning.

Testing and Commissioning Phase

Regardless of whether a facility is newly constructed or adapted from an existing building, the testing and commissioning phase is largely the same. Although all equipment is tested by manufacturers before shipment and retested on site upon arrival, data center operators must perform integrated systems testing once all equipment is installed and connected. This ensures that power and cooling systems work together across all load levels. Teams also simulate utility outages to confirm that UPS systems and generators activate as expected in an emergency.

Greenfield Vs Adaptive Reuse Timelines

If you’re interested in adaptive reuse as an option for data center space, contact us at sales@raeden.com to get started.