There is dust and noise from breaking out the perimeter slab, and the work zone runs along the protected walls, but it is contained to the basement and cleaned up daily. Most of the basement stays usable. Exterior excavation is far more disruptive to the yard; interior is the low-disruption option.
More detail
Interior drainage is the low-disruption choice, but it is honest to set expectations. The work involves saw-cutting and breaking out a channel in the perimeter slab, which is dusty and noisy for the portion of the job when concrete is being cut and removed; we control dust as much as practical and clean up debris daily, but a basement under active installation is a work zone. The disturbance is confined to a band along the walls being protected, so the center of the basement and anything not against the protected wall generally stays in place, though you will want to clear belongings away from the perimeter before the crew arrives and expect that area to be inaccessible during the work. The slab is poured back flush at the end, leaving a clean finished floor, and a typical job is a 1 to 2 day event rather than a prolonged construction project. By contrast, exterior excavation is genuinely disruptive outside: it means an excavator, an open trench along the foundation, and the removal of whatever landscaping, patio, deck, or driveway sits in the way, with restoration afterward, over a multi-day span weather permitting. That contrast (contained interior dust for a day or two versus a torn-up yard for a week) is a major reason interior drainage is the default Cincinnati recommendation when the failure mode allows it. For finished basements, the disruption is higher on the interior side too, because finishes along the protected wall have to come out and go back, which we scope into the job. We walk you through exactly what will happen, where, and for how long during the assessment, so there are no surprises about dust, access, or duration on install day.