Bay and Bow Windows in Lansing: More Light, More Room

A bay or bow window pushes the wall outward, adding a few square feet of floor space and a view in three directions. In a Lansing winter, when daylight is short, that extra glass can change how a room feels. It also adds a lot of work above and below the window, which is where many older bay units around town have started to fail.

Bay or Bow?

• Bay windows use three units: a wide fixed or double-hung window in the middle and two narrower windows on angled sides, usually at 30 or 45 degrees.
• Bow windows use four, five or more equal-width units in a shallow curve. They project less and look softer from the street.

Which one fits depends on the width of the opening, how far you want it to stick out and the style of the house.

What Goes Into a Good Installation

Because a bay or bow hangs outside the wall, it needs support. That may be cable systems anchored to the framing above, knee braces underneath, or a framed base on a foundation. On top it needs a small roof, either a copper or metal cap or shingles tied into the siding, with flashing that holds up to ice and snow. Underneath, the seat board and the space below it need insulation, because a cold seat is the most common complaint we hear about older units.

Signs an Old Bay Window Needs Replacing

• A seat board that sags, feels cold or shows water stains
• Gaps between the unit and the wall, or daylight at the corners
• Ice buildup on the roof cap or leaks into the ceiling below
• Fogged glass in one or more of the units

Replacing a failing bay or bow is usually done as a complete assembly, with new support and a new roof cap, rather than swapping the glass alone. If you would rather keep a flat wall, a large casement or picture window combination is another way to get the light.