Draft is the most common complaint we hear and the one with the widest range of causes, which is exactly why it is the one homeowners most often get oversold on.
Sometimes it is a genuinely cheap fix. Sometimes the window is fine and the problem is somewhere else entirely.
Four different things get called a draft.
Air infiltration. Actual moving air, through worn weatherstripping, a failed sash lock that no longer pulls the sashes tight, or gaps where the frame meets the wall. This is the true draft and it is usually the most fixable.
Radiant loss. No air is moving at all. The glass surface is simply cold, and your skin reads the heat leaving your body toward that cold surface as a draft. Common with single pane and with failed insulated units.
Frame conduction. Aluminum frames conduct cold straight through to the interior. The frame becomes a cold bridge, the surrounding air chills and falls, and you feel it as a draft near the floor. Very common on Denver and Aurora homes from the 1950s through the 1970s.
Convection current. Cold air near the glass sinks, warm air moves in to replace it, and the room develops a slow circulation that feels like a draft with no actual leak anywhere.
Diagnosis matters because the fix for one is worthless against another.
Depends which one you have.
Air infiltration: usually yes. Weatherstripping replacement, hardware adjustment, sash lock repair, and re-caulking the exterior perimeter are real fixes at modest cost.
Radiant loss from a failed seal: sometimes, via glass unit replacement. See foggy glass.
Frame conduction on aluminum: no. This is the one where we will tell you not to spend money on a partial fix. You cannot weatherstrip your way out of a frame that is acting as a heat sink, and a glass upgrade inside an aluminum frame leaves most of the problem in place.
Convection on old single pane: not repairable in any meaningful sense. That is a replacement conversation.
Two things worth checking yourself, because they cost nothing and they occasionally solve the whole problem.
Feel around the frame perimeter on a windy day. If you find moving air at the edge where the window meets the wall rather than at the sash, the problem may be exterior caulk and trim rather than the window.
Check that your sash locks fully engage. On double hungs the lock does not just secure the window, it pulls the two sashes tight against each other. A lock that is misaligned leaves a gap along the meeting rail every day of the winter.
No number here, for a reason that should be obvious from everything above.
There are four different problems on this page that all get called a draft, and they range from a weatherstripping swap to a full replacement. Quoting a draft repair without seeing the window would mean picking one of four causes at random. That is not pricing, it is a coin flip with a dollar sign on it.
What we can tell you is that repair moves fast. A visit is a look, a diagnosis, and a number, not a four hour presentation. Most draft diagnosis happens on site in minutes, and you will know which of the four you have before we leave.
Then you decide. No deposit to get a number, no pressure at the door, and you set the schedule.
We are not going to hand you a number for what this saves on your utility bill. Nobody selling windows can honestly produce that figure, because it depends on your insulation, your HVAC, your habits, and the weather. Anyone who gives you a specific savings figure or a payback period is guessing with a calculator in their hand.
What we will do is show you the actual performance ratings on whatever we quote and explain what each number means.
Related: foggy glass · windows that will not stay open · all window repair
No deposit to get a number, no four hour presentation, and you pick the start date.