Electrical in Multi-Tenant and Mixed-Use Buildings

How Is the Electrical Arranged in a Multi-Tenant Building?

Multi-tenant electrical arrangements decide who pays for what, who is responsible when something fails, and how disruptive any future work will be, which makes them worth understanding before a problem forces the issue.

The supply comes into the building once. From there it is split, and how it is split is the whole subject. In a typical arrangement each tenant has their own meter and their own panel, fed from a distribution point, and pays the utility directly for what they use. Alongside that sits the house supply, which is a separate meter and panel for everything that belongs to the building rather than to a tenant.

The house side covers common area lighting, corridors and stairwells, exterior and parking lighting, the fire alarm, elevators, boiler and pump controls, and any shared HVAC. It is billed to the landlord or through the service charge, and it is frequently the part nobody has looked at in years.

Where buildings become difficult is where that structure was never clean to begin with, which in converted mill buildings across Manchester, Lowell, Lawrence and Dover is more the rule than the exception.

It is the defining issue in the converted buildings we work in most, across Manchester's Millyard, Dover and Somersworth in New Hampshire, and the Lowell, Lawrence and Haverhill mill districts in Massachusetts.

What Is a House Panel and Who Is Responsible for It?

The house panel feeds everything that serves the building rather than any individual tenant, and responsibility for it sits with the owner or the managing agent rather than with anyone renting a unit.

It is the single most neglected panel in most commercial buildings, precisely because nobody trading in the building thinks of it as theirs, and it is usually the first thing a maintenance program picks up. It carries the loads that matter when something goes wrong, which is emergency lighting, exit signage, fire alarm, and in many buildings the pumps and controls that keep everything else working.

The pattern we see repeatedly is a house panel that has accumulated forty years of additions with no record. Circuits added for a tenant who left a decade ago, feeds to equipment nobody can identify, and labelling that stopped being accurate long ago. In older converted buildings that accumulation is genuinely the main risk in the building.

Getting it surveyed, labeled and documented is unglamorous work that pays for itself the first time something fails, because the alternative is finding out what a circuit does by switching it off during trading hours. Property management and multi-family electrical work is mostly this: knowing what is there before it matters.

Should Tenants Be Separately Metered?

In almost all cases yes, and where a building is not separately metered it is usually worth fixing rather than working around.

Separate metering means each tenant pays the utility for what they actually use. It makes the bill the tenant's problem rather than an apportionment argument, it removes the landlord from the position of reselling electricity, and it changes behavior in a way an apportioned charge never does. A tenant with a meter turns things off; a tenant paying a share of a total does not.

The alternative arrangements are worse in predictable ways. A single meter with the cost divided by floor area penalises the light user and subsidises the heavy one, which in a building with one restaurant and three offices is a real grievance. Sub-metering, where the landlord meters tenants privately and recharges, is workable but brings its own rules about what may be charged and how.

Retrofitting separate metering into an older building is a real piece of work, because it means separating circuits that may have been combined for decades and finding space for meters. Tenant metering and sub-metering is usually the largest single electrical project one of these buildings has. In a converted mill floor that can be the largest single electrical project the building ever has, and it is usually still worth doing.

What Electrical Work Happens at a Unit Turnover?

More than most owners schedule for, and a turnover is by a distance the cheapest moment to do any of it because the space is empty.

The baseline is making the unit safe and legal for the next tenant, so testing what is there, checking the panel and its terminations, verifying GFCI protection where it is now required, confirming emergency and exit lighting works, and replacing whatever the last tenant damaged or improvised.

Then there is removing what they added. Tenants add circuits, and a departing tenant frequently leaves behind wiring for equipment that has gone with them. Leaving dead and unidentified circuits in a panel is how the next decade of confusion starts, which is why tracing and making safe is part of a turnover rather than an extra.

The third part is what the incoming tenant needs, and that depends entirely on the change of use. A retail unit becoming a restaurant is a different order of work from an office becoming an office, and the fit-up scope follows the change of use rather than the floor area. Establishing that before the lease is signed rather than after is worth a great deal, because the answer occasionally is that the unit cannot support the intended use without a service upgrade.

Who Pays for Electrical Work in a Leased Commercial Unit?

The lease decides it, and the disputes almost always come from parts of the building the lease never explicitly addressed.

The general shape is that the landlord owns the building supply, the house services and anything structural, while the tenant owns what is inside their demise and anything they installed. That works cleanly until something sits on the boundary.

The boundary cases are where the arguments happen. The panel serving a unit, which may be inside the demise or in a shared riser. The feeder to that panel, which runs through common parts. A service upgrade needed because of one tenant's equipment. Emergency lighting inside a unit that is part of the building system. Rooftop HVAC serving one tenant but mounted on the landlord's roof.

None of those is an electrical question, but all of them become one when something fails. The useful thing a survey provides is a clear picture of what feeds what, which turns a lease argument into a factual one.

What Are the Common Problems in Converted Mill Buildings?

The mill conversions across Manchester's Millyard, Lowell, Lawrence, Haverhill, Dover and Somersworth share a set of issues, and they come from the same history rather than from bad work.

These buildings were wired for one purpose, converted for another, and then subdivided repeatedly. Each round of tenancy added circuits without removing the previous ones. The result is distribution that grew rather than being designed, with feeders running through spaces they no longer serve, panels fed from panels fed from panels, and circuits that cross what are now separate tenancies.

Three-phase supply is frequently inconsistent within one building, because it was brought to whichever floor a previous tenant paid for. Original industrial-era infrastructure sometimes remains alongside the modern installation. Fire separation between units has often been compromised by cable routes punched through it over the years.

None of this makes the buildings bad, and they are frequently excellent commercial space. It does mean that a survey before a fit-up is worth considerably more in a converted mill than in a modern unit, because the gap between what the drawings say and what is actually there is widest here. Distribution and feeder work in these buildings starts with finding out what exists.

What Should a Property Manager Have Documented?

What feeds what, where the isolation points are, and when anything was last inspected. Those three turn every future incident from an investigation into a job.

Concretely that means an accurate single line diagram or at minimum a clear record of the distribution, every panel surveyed and correctly labeled, the house services identified and separated from tenant supplies, and the emergency and life safety systems documented with their test records.

The value shows up at the worst moments rather than the routine ones, which is when an after-hours callout is either a short job or an investigation. A fault at nine on a Friday evening in a building where nothing is labeled is hours of tracing before any repair starts, and those hours are billed while tenants are without power. The same fault in a documented building is a short job.

Multi-tenant electrical work is mostly about knowing what is there, which is why we start with a survey rather than a quote. We look after common areas, house panels, turnovers and distribution for managing agents across Manchester, Nashua, Portsmouth, Dover and Concord, and in the Merrimack Valley mill cities on the Massachusetts license.