Office buildings present a specific set of radon challenges that a single-family home simply doesn’t have: multiple tenants under one lease structure, ground-floor lobbies and parking areas in direct contact with soil, shared HVAC systems serving many separate suites, and a workforce that spends the entire business day in the building. This post covers what office building owners, property managers, and tenants in Pennsylvania need to know about radon testing and mitigation. For the complete picture, see our complete guide to commercial radon testing and mitigation in Pennsylvania.
Why Office Buildings Are a Distinct Case
An office building differs from other commercial radon scenarios in a few important ways:
- Full-day occupancy. Office employees typically spend 35 to 40+ hours a week in the same building, week after week, year after year — comparable exposure duration to a homeowner, but across a much larger group of people and often without any awareness that testing has or hasn’t happened.
- Ground-floor and below-grade space. Lobbies, ground-floor suites, mailrooms, and especially below-grade parking garages sit in the most radon-exposed part of the building, yet are often the least-monitored spaces because no single tenant is responsible for them.
- Multi-tenant complexity. In a multi-tenant office building, radon testing and mitigation decisions often sit with a landlord or property management company rather than any individual tenant, which means the party best positioned to notice a problem is not always the party who would occupy the affected space.
- Engineered HVAC systems. Office buildings typically run variable air volume (VAV) systems or similar engineered ventilation that actively manages air pressure and exchange throughout the day — a factor that has to be accounted for in both testing and mitigation design.
Whose Responsibility Is Radon Testing in a Leased Office Building?
This question comes up constantly, and the honest answer is that it depends on the lease. In most commercial leases, responsibility for building systems and structural elements — which is where radon testing and mitigation typically fall — sits with the landlord or property owner, not individual tenants. That said, tenants are increasingly the ones asking the question, particularly larger employers with formal environmental, health, and safety policies, or tenants in fields like healthcare, education, or childcare who have their own duty-of-care obligations to their own employees or clients. If you are a tenant and radon has never come up, it is a reasonable, low-friction question to raise with your landlord or property manager — testing costs little relative to the liability question it resolves for everyone involved.
Testing an Office Building
Office building testing generally focuses first on every ground-contact and below-grade space — lobbies, ground-floor suites, mailrooms, storage areas, and parking structures — since those are the areas where soil gas infiltration is most likely. Upper floors are typically not tested unless there is a specific reason to suspect vertical migration through shared shafts, elevators, or stairwells, which can occasionally carry radon upward from a below-grade source in older or less airtight buildings. Testing follows EPA protocol for measurement in large buildings, and results are compared room by room against the EPA’s action level of 4.0 pCi/L rather than reduced to a single building-wide average.
How Mitigation Works in a Multi-Tenant Office Building
Mitigation design in an office building has to account for the fact that the building will keep operating with staff and visitors present throughout installation, and that the finished system will need to coexist with the building’s existing HVAC rather than override it. Common approaches include:
- Sub-slab depressurization systems placed to address the specific ground-floor zones that tested elevated, rather than the entire building footprint by default.
- Coordination with the building’s mechanical contractor so the mitigation fan’s exhaust and pressure relationships don’t conflict with rooftop units or makeup air intakes.
- Mitigation of below-grade parking garages, which sometimes requires a different approach than occupied office space, since garages are semi-ventilated by design.
- Discreet routing of piping and exhaust stacks to minimize visual impact on a building’s exterior — a common concern for Class A office properties and multi-tenant landlords.
The underlying engineering principles are the same ones covered in our post on how commercial radon mitigation systems work, applied specifically to the multi-tenant, HVAC-integrated layout an office building presents.
Radon and Commercial Real Estate
Radon testing history is also worth checking before buying, selling, or leasing office space. A clean, documented test is a selling point in a competitive leasing market, and a building with no testing history at all can raise questions during due diligence. If you are evaluating an office property as a buyer, seller, or tenant, our guide to commercial real estate radon testing before you buy or lease covers what to ask for and when to order your own independent test.
Mixed-Use and Coworking Buildings
A growing share of Pennsylvania’s office stock isn’t a single-tenant corporate building anymore — it’s mixed-use retail-and-office buildings, converted historic properties, and coworking spaces with dozens of member companies sharing one floor plan. These properties add an extra wrinkle: ground-floor retail tenants and upper-floor office tenants may have completely different landlords or management structures even within the same building, and a coworking operator managing a shared floor for hundreds of daily visitors has an even broader group of people relying on someone else having already checked the air quality. If you operate or manage a mixed-use or coworking property, it is worth confirming explicitly who owns the radon question — rather than assuming another tenant or the base building owner already has it covered.
Get Your Office Building Tested
Whether you own, manage, or lease office space in Central Pennsylvania, radon testing is a straightforward way to close an open question about the building’s safety for the people who spend their workday there. PA Radon Pros provides certified office building radon testing and mitigation across the region, with mitigation systems designed to work alongside your building’s existing HVAC. Request a free quote or call us at (844) 945-4329.
