Q. My clients love the look of the original diamond-grid metal casement windows in their historic stone house, but they are not happy with the windows' performance in cold winter weather. The outswinging casements have been fitted with fixed interior storm windows, but they can't be opened for ventilation during the spring or fall and they are difficult to install and remove. Are there any companies that manufacture storms and screens or an insulated sash for outswinging single-glazed metal casement windows?

A.John Seekircher, owner of Seekircher Steel Window Repair in Peekskill, N.Y., responds: The best solution I've found to this tricky problem is a magnetic storm window offered by New York Window (347/538-2075), a fabricator/supplier that specializes in the repair and restoration of commercial and residential metal windows.

In some cases, the company's magnetic storm windows can be mounted directly on the interior side of a casement window sash, so they won't interfere with the window's operation.

Where a handle or window operator interferes with this kind of installation, the company will fabricate an auxiliary track that can be mounted to the existing window; the magnetic storm then mounts to the track.

The window is easy to remove and satisfies code and egress issues.

It has a narrow 7/8-inch-wide profile and an integral bellows (similar to the gasket found on a refrigerator door) to account for atmospheric pressure differentials, and it can be fitted with acrylic, laminated, or tempered glass in various thicknesses.

Costs start at about $10 to $12 per square foot. As you might guess, accurate dimensioning of the existing window is important for these custom-fabricated storm units.

The windows accommodate a couple of different types of screens. There is a magnetic screen that can be snapped into place on the same track. On larger windows, a wicketlike opening built into the screen can be used to access the window's operator, while on smaller windows the screens can simply be removed and replaced to open or close the window.

Prices for screens start at about $100 for a typical 3x5 window.

For high-end applications, the company also offers a rollaway screen; prices for a 3x5 window start at about $225 or so.