What does T1 typically refer to in project documentation?

In project documentation, T1 typically refers to the layout of a complete building per floor. This level of documentation provides crucial information about how each floor of a building is structured, including the placement of walls, doors, and other architectural elements, which is essential for understanding how the space can be utilized. Clear representation of each floor's layout aids in planning for installations, such as cabling and networking, ensuring that technicians and engineers have a comprehensive overview of the environment in which they will be working.

While the other options are relevant in different contexts, they do not embody the full representation of a building's layout as effectively as the correct choice. Service zone boundaries relate to specific areas where services are managed, safety compliance pertains to meeting regulatory requirements, and horizontal cable pathways focus on the routes cables will take rather than the complete layout of the building. The layout of complete building per floor captures a broad and essential element of project documentation, making it the right choice in this context.