Plenty of Austin houses still have single-pane glass. You find it in bungalows and cottages in Hyde Park and Travis Heights, in mid-century ranch homes around Allandale and Crestview, and in some rental properties that have changed hands for decades without anyone touching the windows. If you live in one, you already know the symptoms: the couch by the window is the warm seat in summer and the cold seat in January, and you can hear every car on the street.
Moving to double-pane glass is the single biggest jump in window performance a house like that can make. Here is what actually changes, and what to look for so the upgrade lives up to its promise.
What a second pane does
A single sheet of glass is a thin, fast path for heat. Whatever temperature it is outside, the inner surface of that glass gets close to it, and you feel it from across the room.
A double-pane unit, also called an insulated glass unit, seals two sheets of glass around a spacer with a narrow gap between them. That gap is usually filled with argon, a dense, inert gas that slows heat moving from one pane to the other better than ordinary air does. The inner pane stays much closer to room temperature, and that one change is behind most of the comfort people notice after an upgrade.
Low-E makes the second pane far more useful
Two plain panes help. Two panes with a low-E coating on one of the inner surfaces help a great deal more, especially in a climate where the sun does most of the damage. The coating reflects infrared heat while letting daylight through. When you compare quotes, ask which surface is coated and what the glass is rated for, because “double-pane” alone tells you very little.
Comfort you notice in the first week
Energy savings show up on a bill a month later. Comfort shows up the first afternoon. People who replace single-pane glass usually mention three things.
First, the area near the window becomes usable. A reading chair by the front window or a desk by the back wall stops feeling like a heat lamp in August.
Second, temperatures even out from room to room. Older homes often have one or two rooms that never match the thermostat setting. Glass is a common reason.
Third, cold mornings stop leaving puddles. Austin winters are mild, but on the occasional freezing morning a single pane gets cold enough for indoor humidity to condense on it and run down onto the sill. Over the years that water stains paint and softens wood trim. A warmer inner pane sharply reduces that condensation.
A quieter house
Sound travels through glass much like heat does. Two panes with a sealed space between them interrupt more of it than one pane can. If your street feeds traffic toward MoPac or I-35, if you are under an airport flight path, or if you live close enough to downtown to hear Sixth Street on a Saturday night, double-pane windows take the edge off. They will not make a house silent, but most homeowners find the change obvious, especially in bedrooms.
For houses with serious noise problems, glass with different thicknesses on each side of the gap can help further, because the two panes stop vibrating at the same frequency. Ask about it if noise is your main reason for replacing.
Older homes need a little extra care
Swapping single-pane windows in an older house is rarely a matter of popping in new glass. The original frames may be wood that has been painted many times, aluminum that has corroded at the corners, or openings that have shifted out of square as the house settled. Clay soils in parts of the metro move foundations, and the windows are often where that shows. A good installer measures every opening individually and seals the new frame to the house so that air does not simply leak around it.
If your home is inside a City of Austin local historic district, exterior changes such as window replacement need review first. Check with the City’s Historic Preservation Office before you sign anything, so the style and profile you choose will be approved.
Picking the right style for each opening
Double-pane glass comes in every style, so you do not have to change the look of the house to get the performance. Double-hung windows suit most older homes, because both sashes move and the proportions match traditional openings. Picture windows work for wide living room views, and casements suit spots where you want a tight seal and good airflow. We can match grid patterns and colors to the character of the house or to your HOA’s rules.
If you are living with single-pane glass and are tired of rooms that never feel right, call The Window Source of Austin at (512) 524-9455 for a free in-home estimate. We will look at every opening and tell you plainly what we recommend.