When Apartment Windows Are Due for Replacement

Siding announces itself. A wall that is failing looks like a wall that is failing, and everyone from the board to the residents can see it. Windows are quieter. They degrade across a decade, unit by unit, and the case for replacing them has to be assembled out of records rather than photographs.

This is a guide to reading those records — what actually indicates end of life across a portfolio, what is just a repair, and how to survey a building well enough to put a real number in front of a board.

The signals that matter, in order

1. Seal failure spreading, not scattered

A fogged pane means the seal on an insulated glass unit has failed and moisture is now inside the cavity. One or two is a glazing repair. What matters is the pattern: insulated units installed in the same year tend to fail in the same few years, so fogging that appears across multiple units and elevations within twelve to eighteen months is telling you the whole population is at the end of its service life. Track the count by quarter rather than the total. A rising rate is the signal; the absolute number is not.

2. Operability complaints that repairs do not fix

Sashes that will not stay up, cranks that bind, sliders that need two hands. Individually these are hardware repairs. But balances, operators and rollers are consumables with a service life, and once a building starts through them the repairs recur. When the same unit needs the same fix twice in two years, you are no longer maintaining — you are subsidising a replacement you have not decided to make yet.

There is a habitability dimension too. A window that will not open is an egress problem in a bedroom, and that is a different conversation than a comfort complaint.

3. Air and water at the perimeter

Drafts, condensation on the frame, staining on the sill or the wall below. These usually indicate that the perimeter seal has failed rather than the window, and they are worth separating in your records because the fix is different. Perimeter failures can sometimes be addressed without replacing the window — but if they are widespread, the flashing details behind the cladding are suspect, and that is a conversation about the wall as well as the glass. Our guide to what belongs in a multifamily siding scope covers the wall side of that.

4. Single-pane and early aluminum stock

Plenty of Northern California multifamily stock built before the mid-1980s still has single-pane aluminum windows. These are not failing so much as obsolete: the frame conducts heat, there is no thermal break, and no repair changes that. If you have them, the question is when to replace rather than whether — and our page on upgrading from single to dual pane covers what changes when you do.

5. Energy cost you cannot attribute

Where the property pays for heating or cooling in common areas or in master-metered units, a slow rise in cost per square foot that survives a rate adjustment is worth investigating. It is rarely conclusive on its own — HVAC age and envelope condition both confound it — but it corroborates the rest.

What does not indicate end of life

• Cosmetic frame wear. Chalked or faded frames look bad and tell you nothing about whether the window works.
• Condensation on the glass surface. Water on the room side of the glass is usually a humidity and ventilation problem, not a window failure. Water between the panes is the failure.
• A single bad elevation. West and south elevations take far more heat load and will always look worse. Judge the building on the pattern across all elevations, not on its worst wall.

How to survey a building without surveying every unit

The point of a survey is a defensible number, not a complete inventory. A sample gets you there:

• Cover every elevation. Exposure drives failure, so a sample weighted to one side will mislead you in whichever direction that side is unusual.
• Take the top and bottom floors. Top floors see the most thermal movement; ground floors see the most physical wear and the most security hardware.
• Over-sample west-facing units. In the Sacramento Valley these carry the heaviest solar load and fail first, so they show you where the building is heading.
• Record by failure type, not by unit. A count of “bad windows” does not support a decision. A count of seal failures, hardware failures and perimeter failures does, because each one points at a different remedy.
• Photograph the frame condition at the sill. This is where you find out whether the surrounding wall is dry — and whether a retrofit installation is even available to you.

That last point is the one that changes the budget most. If the frames are sound, a retrofit installation is usually possible and considerably less disruptive. If they are not, you are into full-frame replacement with cladding work at the perimeter. We cover the difference in retrofit versus full-frame windows for apartment buildings.

Building the case for the board

Boards and owners do not fund conditions, they fund consequences. The version of this that gets approved usually has four parts:

1. The trend — window work orders by quarter for the last two or three years, which is the difference between “the windows are old” and “this is accelerating”.
2. The recurring spend — what maintenance is already costing annually, which is the number the replacement is measured against.
3. The survey — a sample-based condition summary with failure types, so the scope is defensible.
4. The funding path — whether this is one project or phased, and what each phase costs. Our page on exterior repair reserve planning covers how this sits in a reserve schedule.

One timing note worth knowing

California’s energy standards for replacement windows changed on 1 January 2026, and they apply according to when the permit application is submitted. For a phased project running across several years, that means an early phase and a late phase can be held to different specifications — which matters if you care about the building matching. It is worth confirming the current requirement before the first phase is specified rather than after. Our guide to Title 24 compliance for multifamily window replacement covers what applies and where.

Working with Heritage Exteriors

We have re-glazed and re-clad apartment communities, condominium associations and commercial buildings across Sacramento, the Bay Area and Northern California, and we are a licensed California contractor (CSLB #1055919). If you want a condition summary you can take to a board, we will walk the property, sample properly, and give you the findings in writing — including the honest answer where the finding is “not yet”.