When a Leak Hits a Tenant's Space
How Office Building Owners Use ELD to Settle the Liability Question Before It Becomes One
Water reaches a tenant's server room on the top floor of a multi-tenant office building. The tenant's IT equipment is damaged, their team is displaced for two days, and the first question nobody can answer cleanly is whose responsibility this is. The roofing contractor who installed new HVAC curbs for a different tenant eight months ago says their work was tested clean. The property manager has no record confirming or disputing that. And now there are two insurance carriers, a tenant relationship, and a lease renewal all sitting on an unresolved timeline question.
For office building owners and property managers, a roof leak is rarely just a maintenance event. It's a liability question waiting for a trigger, and the building's roofing history usually isn't documented well enough to answer it quickly.
The Lease Says Who's Responsible. It Doesn't Say When the Breach Happened.
In most commercial lease structures, gross, modified gross, or triple net, the landlord retains responsibility for the building's structural elements, including the roof. That much is usually clear. What isn't clear is when a given breach occurred relative to a tenant's move-in date, a recent tenant improvement project, or the last time anyone tested the membrane. Without that timeline, responsibility becomes a negotiation instead of a fact.
Office tenants concentrate a lot of value in a small footprint, server rooms, data closets, network equipment, and a leak that reaches that kind of space is a business continuity problem for the tenant as much as a maintenance one for the owner. We cover that broader operational risk in more depth on our Property Management page. What this post focuses on is narrower: the moment a leak reaches a tenant's space and the building has no record to say when the breach started or who's responsible for it.
Why Office Roofs Accumulate Risk Over Time
A single-tenant industrial roof is tested once and largely stays the same. A multi-tenant office roof changes constantly. New tenants mean new rooftop HVAC units, new curbs, new cabling penetrations for signage or equipment. Every one of those additions is a fresh opportunity for a breach that wasn't there the last time anyone looked, and few buildings retest after each round of tenant improvement work.
An often-cited industry figure still holds up: water intrusion accounts for more than 70 percent of construction litigation (Architect Magazine, 2011), and buildings with frequent rooftop modifications from ongoing tenant improvement work are exactly the setting where that kind of dispute tends to originate, since responsibility gets harder to trace with every added penetration.
What ELD Gives Building Owners That a Visual Walk-Through Doesn't
An electronic leak detection survey establishes a documented, GPS-mapped baseline of membrane condition at a specific point in time. Run before a tenant improvement project breaks ground and again after it's complete, that baseline turns "the roof was fine before your work" from an assumption into a fact. The survey should come from a third party independent of whichever contractor did the roofing or TI work, not a self-inspection, so the documentation holds up if a dispute does arise later.
What Waiting Costs
Consider an office building that adds rooftop HVAC units for a new tenant's build-out. Eight months later, a different tenant's server room takes on water. The GC who installed the new units says their work tested clean at closeout. The property manager has nothing on file to confirm or dispute that. Both insurance carriers point at each other, the repair happens eventually, but the relationship with the affected tenant, and the renewal conversation that follows, absorb the damage.
Run the same sequence with an ELD survey before and after the HVAC installation. The pre-work baseline and the post-work verification are both on file. When the leak shows up eight months later, the timeline already answers the question everyone would otherwise be arguing about.
Building ELD Into the Tenant Improvement Cycle
Test before and after any tenant improvement work that adds rooftop penetrations, curbs, or equipment.
Schedule a follow-up survey any time a new tenant's build-out touches the roof.
Require third-party, independent testing rather than a self-inspection from the TI contractor.
How Honza Group Supports Office Building Owners and Managers
Honza Group provides electronic leak detection for multi-tenant office properties, before and after tenant improvement work, and as part of ongoing roof maintenance programs. We deliver GPS-mapped reports that establish a clear, independent record of membrane condition, so when a dispute over timing or responsibility comes up, the documentation is already there.
If you're managing a building with active tenant improvement work, or want a documented baseline before your next lease renewal cycle, we'd value the conversation.
Sources referenced in this post:
Architect Magazine — When It Leaks It Pours (2011) — water intrusion's share of construction litigation
ASTM D7877 — Standard Guide for Electronic Methods for Detecting and Locating Leaks in Waterproof Membranes, the governing industry standard for ELD methodology
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