Turnarounds change everything about how a facility operates. Headcount increases, work scopes overlap, and activities that are normally separated in time or space are compressed into a narrow window. The result is a higher concentration of people working in areas where hazard conditions are also changing.
Temporary buildings are often brought in to support that surge. Offices, break areas, control spaces and planning rooms all need to be placed somewhere inside an already constrained unit. These temporary occupied buildings can range from standard trailers to blast-resistant buildings, depending on the level of protection required. Where those structures are located and how they are designed will directly affect both safety and compliance.
This is where planning temporary buildings during a turnaround tends to fall short. The level of protection those structures provide varies significantly, and that difference is central to how they should be planned and placed. Blast-resistant buildings should not be treated as a late-stage logistics task, after layouts are already defined and space is limited. At that point, options narrow quickly, and decisions are driven more by availability than by risk.
The need for blast-resistant buildings should be addressed early, alongside siting, headcount projections, and unit layout, not after them. Understanding how that process actually unfolds is the difference between a plan that works on paper and one that holds up in the field.
The Real Timeline for Planning Occupied Buildings for Turnarounds
Turnaround planning follows a predictable sequence, but decisions around occupied buildings—particularly those requiring blast resistance—introduce additional constraints at each stage.
6–12 Months Out: Early Planning and Hazard Review
Before any buildings are ordered or placed, the focus is on understanding risk, not selecting structures. Within that process, planning for temporary occupied buildings—particularly those requiring blast resistance—introduces its own set of constraints and decisions.
Facility siting studies, typically aligned with API RP 752 and 753, provide the baseline for evaluating where personnel can safely occupy space. These studies define hazard zones, expected overpressure ranges and acceptable building locations within the unit. For turnarounds, those assumptions often need to be revisited, based on the planned scope of work.
It’s during this time frame that early headcount projections begin to take shape. Contractor labor, inspection teams and specialty crews can significantly increase the number of personnel on site. Those individuals will require space for planning, coordination and breaks, which means identifying where temporary buildings could realistically be placed.
This is also when early conversations with vendors should begin. Start by talking about the site's constraints and looking at feasibility. Waiting until later stages to have those discussions often leads to limited options and rushed decisions.
3–6 Months Out: Engineering and Siting Decisions
As turnaround planning progresses, planning for temporary occupied buildings shifts from general assessment to defined engineering decisions.
Blast loads are confirmed based on updated facility siting studies, including both overpressure and impulse. These values determine what level of protection is required in specific locations. In areas where siting studies support non-blast construction, standard offices may be used. In high-risk areas, blast-resistant buildings would be necessary to meet recommendations.
Layout constraints become more defined during this phase. Access routes, equipment spacing, crane paths and work zones begin to solidify, which directly impacts where temporary buildings can be placed. Space that appeared available earlier in planning may no longer be viable.
This is typically where the distinction between standard offices and blast-resistant buildings becomes critical. The decision is no longer about convenience or cost alone. It is about whether the selected structure aligns with the required level of protection for that location.
1–3 Months Out: Procurement and Logistics Lock-In
By this stage, flexibility begins to narrow.
Building types, quantities and locations should be finalized to support procurement and scheduling. Lead times become a major factor, particularly if leasing blast-resistant buildings is required. Availability, fabrication schedules and transportation logistics all need to align with the turnaround window.
Delays or indecision at this point often force teams into suboptimal choices. Standard trailers may be used where higher protection is warranted, or buildings may be placed in less-than-ideal locations due to availability constraints.
Coordination across teams becomes critical. Procurement, operations, safety and turnaround planners all need to be aligned to ensure that selected solutions can be delivered and installed without disrupting the overall schedule.
Final Weeks: Installation and Readiness
In the final weeks leading up to the turnaround, execution takes priority.
Site preparation, delivery sequencing, and building placement must be coordinated carefully to avoid conflicts with other pre-turnaround activities. Once installed, temporary occupied buildings need to be secured appropriately, including anchoring and tie-downs where required.
Access and egress paths should be verified to ensure safe movement of personnel. Buildings must be placed in locations that support both safety and operational flow, not just convenience.
Final checks focus on confirming that the installed structures align with siting expectations and the planned level of protection. At this stage, there is little room for adjustment, which is why earlier planning phases are critical.
Where Turnaround Plans Fall Short on Occupied Buildings
Even when turnaround planning is well organized, decisions about blast-resistant buildings are often where plans begin to diverge from actual site conditions. These issues are usually the result of a series of small assumptions that compound over time.
One of the most common issues is underestimating peak headcount. Early projections may not fully account for all contractors, specialty crews or overlapping work scopes. As the turnaround approaches, additional personnel are added, but the plan for these buildings remains unchanged. This leads to overcrowding or the need to introduce additional structures late in the process, when placement options are already limited.
Another frequent gap occurs when standard trailers are used without fully evaluating whether they meet the required level of protection for their intended location. In some cases, an evaluation would indicate that blast-resistant buildings are required to meet siting expectations for that area. In lower-risk areas, trailers may be appropriate. In higher-risk zones, a blast-resistant building aligns better with siting expectations. When that distinction is not addressed early, it often results in last-minute adjustments or acceptance of higher risk than originally intended.
Siting decisions are also commonly delayed until layout constraints are already established. By the time building placement is finalized, access routes, equipment spacing and work zones may leave few viable locations. This forces buildings into suboptimal positions, where they may conflict with operations or fall outside preferred siting zones.
Timing plays a critical role as well. When decisions about occupied buildings are pushed too far into the planning process, procurement options become limited. Availability, fabrication timelines and transportation constraints begin to dictate what can be deployed, rather than what is most appropriate for the site.
In many cases, these limitations are not immediately visible on paper. Plans may appear complete, but once execution begins, the constraints become clear. Addressing these gaps requires recognizing that planning for occupied buildings is not a secondary task. It is a core part of turnaround planning that needs to be addressed with the same level of rigor as siting, scheduling and execution.
Critical Decisions That Impact Safety and Schedule
Turnaround planning involves many individual decisions, but some have a significant impact on both safety and execution. Decisions about occupied buildings fall into that category because they influence where people are located, how they move through the unit and how protected they are during high-risk activities.
One of the first critical decisions is where occupied buildings can be safely placed. This is not simply a matter of convenience or available footprint. It is driven by siting evaluations, which define acceptable locations based on potential blast loads and other hazards. Placing buildings outside of those preferred zones introduces risk that is difficult to mitigate later.
Closely tied to location is the question of what level of protection is required. Blast loads vary across a unit, and not all areas require the same level of protection. In low-risk areas, standard trailers may be appropriate. In higher-risk zones, blast-resistant buildings needed to meet the requirements of siting evaluations.
Another key decision is whether the selected structures match the intended use and occupancy. Planning spaces, break areas and control rooms may have different occupancy durations and densities, which can influence both their placement and protection levels. Treating all temporary buildings the same often leads to mismatches between how they are used and how they are designed.
When buildings are placed is another factor that directly affects both safety and schedule. Buildings must be available when needed, but they also need to be placed in a way that does not interfere with ongoing work. Late-stage changes can disrupt access routes, create congestion or conflicts with other tasks that directly impact the schedule, like shutting down a unit, repairing equipment or restarting the unit.
Finally, plans need to account for changes as work unfolds. Headcounts shift, scopes expand, and conditions evolve as the turnaround progresses. If building placement and selection are rigid, even small changes can trigger problems. Flexible planning, with an understanding of what can and can’t be adjusted, helps maintain harmony during the project.
These decisions are interconnected. Location influences protection requirements. Protection requirements influence structure selection. Structure selection affects procurement, logistics and placement. When these decisions are made early and in coordination, they support both safety and execution. When they are delayed or made in isolation, they tend to introduce constraints that are difficult to resolve once the turnaround is underway.
When planning starts early and is aligned with siting requirements, teams have more flexibility to select appropriate solutions and place them where they belong. When those decisions are delayed, options narrow quickly, and compromises become more likely.
Understanding how occupied building planning fits into the broader turnaround process helps reduce constraints and leads to earlier, more informed decisions. This understanding will also help you avoid last-minute adjustments and maintain alignment between safety expectations and execution.
In higher-risk areas, those decisions make blast-resistant buildings necessary to meet siting requirements. When that need is identified early, teams have more flexibility to select the right structures, place them appropriately and integrate them into the overall turnaround plan.
If you’re planning an upcoming turnaround and need to evaluate occupied building requirements—including where blast-resistant buildings may be necessary—RedGuard can help assess siting constraints, protection levels and deployment options.
