Why Building Systems Define the Deal
Leasing space in an older office tower can offer genuine advantages — lower face rents, established neighborhoods, character floor plates, and landlords who are often more motivated to negotiate. What older buildings rarely advertise is the gap between a lobby that has been renovated three times and infrastructure that has not been touched in decades. When a tenant signs a lease without understanding the state of the mechanical, electrical, plumbing and structural systems underneath the finishes, every capital and operational assumption embedded in that deal is exposed to risk.
The Case for a Systems-First Evaluation
Most site selection conversations start with location, then floor plate efficiency, then rent. Building systems arrive late in the process — sometimes only when a lease is already drafted and due diligence is squeezed into a narrow window. That sequence rewards landlords and penalizes tenants, because the cost and disruption of aging infrastructure falls entirely on the occupier once keys are handed over.
Sophisticated tenant representatives and corporate real estate leads flip the order. They treat the building systems audit as a filter that screens out deals before the team has spent weeks negotiating economics on a building that cannot deliver the operational environment the client actually needs. That discipline requires knowing exactly what to ask, in what order, and what the answers mean for lease NPV.
Reversing the evaluation order also changes the negotiating dynamic. When an adviser can document that the base building HVAC is at the end of its expected service life, that evidence becomes the basis for a landlord work-letter that shifts capital risk back to the owner — or for a rent credit that is reflected in the effective rent calculation. In practice, the 6 Questions to Ask About Building Systems in an Older Office Tower are not just a due-diligence checklist; they are a negotiating framework.
Question 1: What Is the Actual Age and Remaining Service Life of the HVAC System?
HVAC is the system that tenants interact with every hour of every workday, and it is the system most likely to have been deferred in an older tower. A building marketed as Class B with "recent upgrades" may mean the lobbies were renovated while the chillers, air handling units and cooling towers remain on their original installation schedule from the 1980s or 1990s. The useful life of a commercial chiller is commonly estimated at 20 to 25 years; an air handling unit at 15 to 25 years depending on maintenance quality. If neither number has been reset by documented replacement, the building is carrying latent capital risk.
The right questions go beyond "when was the system installed?" A tenant's adviser should request the building's preventive maintenance logs, the most recent service contracts, and any third-party mechanical assessments the landlord has commissioned. The absence of maintenance logs is itself data — it usually signals deferred maintenance, which accelerates wear. When logs exist, the pattern of emergency service calls versus scheduled maintenance tells an experienced engineer more than the installation date alone.
Tenants should also ask about the system's zoning capacity relative to the floor they intend to occupy. An HVAC system that was designed for a dense open-plan office in 1988 may not deliver adequate fresh-air volume to meet current ventilation standards without modifications, and those modifications are typically the tenant's cost unless negotiated into the work letter.
Understanding the HVAC age also matters for modeling lease economics. If a credible engineer estimates a major capital replacement within the lease term, that future disruption — temporary loss of cooling, construction access, potential downtime — has a real value that belongs in the effective rent comparison. A hypothetical example: if a chiller replacement causes four weeks of reduced occupancy capacity, the indirect cost to a 300-person tenant is not trivial, even before accounting for any lease rent obligations that continue regardless of the building's condition.
Question 2: Can the Electrical Infrastructure Support Current and Future Density?
Power infrastructure is the second major fault line in older office towers. Buildings constructed before the widespread adoption of personal computing were typically engineered for lower watts-per-square-foot assumptions than a modern technology-dependent office requires. If the building has not had a service upgrade since original construction, the gap between available power and actual tenant demand can be significant.
The first thing to establish is the building's total electrical service capacity and the allocation available to the target floor. A landlord who cannot produce a one-line electrical diagram for the building, or who cannot answer how much dedicated capacity is available on the subject floor, is signaling that the systems have not been actively managed. The second data point is the available amperage at the tenant's electrical panel, and whether submetering exists or is feasible. Without submetering, a tenant has no independent visibility into actual consumption — which matters when the building charges for electricity as a pass-through.
Dense computing environments, trading floors, data closets and server rooms introduce loads that an older building's electrical riser may not accommodate without an upgrade. Riser upgrades typically require coordination across multiple floors and may require landlord participation in cost. Tenants running server infrastructure on-site should get an electrical capacity opinion from a licensed engineer before committing to a space, not after.
Emergency power is a related question. What generator capacity does the building maintain, and which systems does it cover — common areas only, or tenant floors? For occupiers with business-continuity requirements, the distinction between a building that runs emergency lighting only and one that can sustain critical tenant loads through a grid interruption is a material difference in operational risk.
Question 3: What Is the State of the Building's Plumbing and Domestic Water Systems?
Plumbing rarely appears in a site selection scoring matrix, but it surfaces in the first month of occupancy as a source of operational disruption disproportionate to its apparent importance. Older towers in many markets were constructed with galvanized steel supply piping, which is subject to corrosion, mineral buildup and eventual failure at a rate that accelerates as the system ages. Cast-iron drainage systems have their own service-life characteristics and can develop failures that affect multiple floors simultaneously.
The question to ask the landlord is specific: what material are the domestic water supply risers, what is their installation date, and has the building conducted a pipe condition assessment using internal inspection or ultrasonic thickness testing? A landlord who has this documentation has been managing the asset proactively. One who cannot answer the question is managing reactively, which typically means tenants absorb the disruption of emergency repairs.
Water quality is a separate but related concern, particularly in towers where the domestic water system feeds pantry and drinking water points. Older piping systems can introduce sediment and contaminants that affect water quality at the point of use. If the building does not have building-wide filtration on the domestic cold-water system, tenants typically install point-of-use filters at their own cost.
Roof drainage and storm water management also belong in this question set, especially for tenants on upper floors or tenants with rooftop rights. A roof membrane at or beyond its design life introduces water infiltration risk that affects the floors below. Roof replacement schedules and the most recent roof inspection report are reasonable requests in due diligence.
Question 4: How Current Is the Building's Life Safety and Fire Protection Infrastructure?
Fire protection systems in older office towers present a nuanced due-diligence question because local fire codes have evolved significantly since most pre-1990 towers were constructed. Grandfathered buildings may comply with the code that was in effect at the time of their construction, even when that code differs materially from current requirements. The compliance status of a building's sprinkler system, fire alarm, stairwell pressurization and emergency lighting relative to the current local fire code is not a question most brokers ask — but it is a question every tenant's lawyer and risk manager should.
Specifically, ask whether the building is fully sprinklered on all floors, including the mechanical rooms, stairwells and elevator lobbies. Ask for the most recent inspection and test report from a licensed fire protection contractor, and ask whether the fire alarm system has been upgraded since original installation. First-generation fire alarm panels can be difficult and expensive to service, and replacement parts may no longer be available.
For tenants planning tenant improvements, the interaction between local building codes and existing fire protection infrastructure is particularly relevant. A tenant installing additional partitions, changing ceiling heights, or relocating sprinkler heads to accommodate a new floor plan triggers permit review. If the existing system does not meet current code, the permit process can require the landlord or tenant to bring the system up to current standard — a material cost that belongs in the work-letter negotiation.
Landlords who have recently completed a fire protection upgrade to current code, or who can provide a third-party assessment confirming current-code compliance, are signaling a well-maintained asset. That documentation meaningfully reduces the tenant's risk exposure and should be reflected in the lease as a representation.
Question 5: What Is the Structural and Building Envelope Condition?
The structural frame of an older office tower is rarely the proximate cause of occupier problems, but the building envelope — windows, curtain wall, exterior cladding and roof — is a frequent source of hidden cost and disruption. Exterior glass and cladding systems installed in the 1970s, 1980s and early 1990s were often designed with gaskets and sealants that have finite service lives. Failed sealants admit water and air infiltration that drives up heating and cooling loads, reduces interior comfort, and can cause damage to the floor below the perimeter.
Ask the landlord whether the building has completed a building envelope study within the last five years. These studies, typically conducted by a curtain wall or building envelope specialist, assess the condition of the sealant joints, the glass units for seal failure (visible as fogging between panes), and the cladding attachment system. If the envelope study has not been done, the tenant is accepting unquantified risk.
For tenants on corner floors or high floors where wind pressure on the envelope is greatest, the condition of the curtain wall matters operationally. A poorly performing exterior wall means perimeter offices are cold in winter and overheated in summer, which compromises the HVAC system's ability to maintain consistent conditions regardless of its own condition. The two systems interact in ways that only appear after move-in.
Structural capacity may also be relevant for tenants planning to install dense filing or records systems, server rooms, or trading floors with raised flooring and equipment loads that exceed standard office design loads. Structural capacity certifications for point loads and concentrated loads should be obtained from a licensed structural engineer, not from the landlord's verbal assurance.
Question 6: What Capital Improvements Has the Landlord Planned, and Who Pays?
The first five questions focus on what the building systems are. The sixth question is about what the landlord intends to do about them — and whether the tenant will fund it through operating expenses. In an older tower, the operating expense passthrough is frequently where building system risk transfers from the landlord's balance sheet to the tenant's income statement.
Capital expenditure passthroughs in older buildings can be significant. HVAC replacements, elevator modernizations, electrical riser upgrades and fire protection upgrades all carry costs that landlords may be passing through to tenants as operating expenses, sometimes amortized over short periods. Before executing a lease, tenants should request a full schedule of planned capital projects and the landlord's intended passthrough treatment for each.
A well-structured lease negotiation caps capital passthroughs or excludes certain categories of capital expenditure from the operating expense base entirely. This requires the tenant's adviser to have identified the likely capital needs of the building before the lease is negotiated — which is exactly why the first five questions must be answered before the economics are locked. The effective rent of a lease in an older tower may look favorable on a face-rent basis and unfavorable when realistic capital passthroughs are incorporated into the net-present-value calculation.
Elevator condition belongs in this question specifically because elevator modernizations in older towers are both expensive and disruptive. Buildings with original hydraulic or early traction systems may be approaching mandated inspection thresholds or facing obsolescence of replacement parts. A landlord with a 10-year-old elevator that has had no modernization work is likely to have that expense arrive during the tenant's lease term. Knowing the elevator maintenance contractor, the inspection history and the modernization schedule is part of a complete systems due diligence.
How to Organize the Answers Before the Deal Closes
The six questions above are worth asking only if the answers are systematically organized, compared across candidate buildings, and translated into economic terms before a final site selection decision is made. Many tenant-side teams collect this information informally — a few notes from a building walk, a summary email from the engineer — and then struggle to compare one building's systems risk against another's when the final shortlist is being evaluated.
A more rigorous approach builds a building systems scoring matrix that translates the engineer's qualitative findings into a numeric score for each system category, weighted by the occupier's operational sensitivity. A law firm with paper-intensive operations weights structural load capacity differently than a technology company with dense computing infrastructure. A financial services tenant with strict business-continuity requirements weights emergency power differently than a creative agency. The scoring matrix is a tool for making those priorities explicit and defensible, rather than leaving them implicit in a committee discussion.
Translating Building Systems Risk into Lease Economics
Understanding building condition is only useful if it changes the financial terms of the deal. The translation from technical finding to economic adjustment requires knowing which lease structures transfer risk to tenants and which protect them. In an older tower, the most common risk-transfer mechanisms are broad operating expense definitions, unlimited capital passthroughs, and "as-is" delivery clauses that relieve the landlord of any obligation to deliver systems in working condition.
Effective rent is the right frame for capturing building systems risk. Where face rent is the gross rent per square foot stated in the lease, effective rent accounts for free rent, tenant improvement allowances, rent escalations and operating expense exposure over the entire lease term — expressed as a present-value figure. A building with a low face rent but significant operating expense exposure from aging systems may carry a higher effective rent than a building with a higher face rent and a newer infrastructure base. Modeling both is a basic competency for any tenant-side adviser; accepting only the face rent comparison is not.
Even illustrative scenario analysis of this kind disciplines the client conversation and forces the landlord's team to address the question directly rather than deferring it.
Who Should Be in the Room During the Systems Audit
A building systems audit in an older office tower is not a task the leasing broker or the in-house real estate lead should conduct alone. The scope of expertise required spans mechanical, electrical, plumbing, fire protection, structural and building envelope disciplines. The right composition for a systems review team depends on the building's age, the tenant's operational sensitivity and the lease size, but the minimum bar for any significant older-tower commitment is an independent mechanical and electrical engineer and a building envelope consultant for buildings with curtain wall systems older than 25 years.
The timing of the engagement matters as much as the team composition. Commissioning an independent engineer only after the LOI is signed limits the team's ability to use the findings in the negotiation. If the LOI is already drafted, it should include a due-diligence contingency that allows withdrawal or renegotiation if the systems audit reveals material deficiencies. A landlord who resists that contingency for an older building is a signal worth taking seriously.
Applying These Questions Across a Portfolio
For occupiers managing multiple locations simultaneously, the six questions scale into a portfolio-wide building systems assessment framework. Rather than approaching each building ad hoc, a portfolio real estate team can establish a standard data request that every prospective landlord completes before site visits are scheduled. That standardization reduces the variation in how findings are reported across different markets and different engineers.
Portfolio-level building systems data also informs lease renewal decisions. A tenant in a building whose HVAC is approaching end of life has a different renewal calculus than one in a building with recently replaced infrastructure.
The portfolio dimension also matters for financial planning. If three buildings in a portfolio of ten are carrying aging electrical infrastructure and the tenant's leases contain broad capital passthrough provisions, the exposure is not purely a leasing risk — it is a facilities budget risk that belongs in the annual planning cycle.
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