New Double Glass in Old Windows?
Does anyone know if it’s possible to replace an old single-paned glass window in a brownstone with new double-paned glass that would provide better insulation? These are floor-to-ceiling parlor floor windows, with four panes per window, but very thin glass. Is it possible to make them more energy-efficient, and if so, any recommendations for who…
Does anyone know if it’s possible to replace an old single-paned glass window in a brownstone with new double-paned glass that would provide better insulation? These are floor-to-ceiling parlor floor windows, with four panes per window, but very thin glass. Is it possible to make them more energy-efficient, and if so, any recommendations for who can do this?
Thanks.
BHS — I’m convinced. So where do you get the nice wood historically accurate storm windows? Most of the ones I’ve seen are metal and not very nice-looking.
The problem with double-paned glass is that the seal between the panes often fails after 5+ years and there’s no simple way to fix this. Also, any window made to hold a single piece of glass is going to look different with two pieces in there. Storm windows essentially add a second pane of glass and are simple to maintain and repair and are historically accurate (or can be, certainly there are non-historically accurate ones). Why not have nice wood storm windows made and a little maintenance for your existing wood windows plus some weather stripping? Certainly this is a safer and likely much cheaper path. Old glass and single paned windows look different in a subtle way that’s part of the charm of a historic house.
Happy Daddy and everyone else who’s done this — please do tell us who did this for you, as most people have told me the same thing they told keep — replace with new windows. I’d love to keep the old ones, though, if it’s not more expensive to do that. But want to make sure I’m using someone who knows what they’re doing.
Happy Daddy – Who did you use to restore? It seems like every place I call in Brooklyn wants me to replace rather than restore.
Just curious HD – how much did one window cost? It sounds like a wonderful solution.
Happy Daddy and the last guy are right! Especially with the full height parlour floor windows, you want to keep the weights. Any good finish carpenter should be able to do this
I can vouch for HappyDaddy’s windows, as I have seen them in person and they work well. I can’t overemphasize the importance of weather stripping as he mentioned. In a brownstone window more heat loss occurs due to convection not conduction or radiation. An insulated glass unit will help more with preventing heat gain and reducing sound transmission. FWIW the further apart the two panes of glass are, the more efficient the unit becomes, that is why storm windows are good- basically it is a 4″ thick insulated glass unit.
We did exactly that. When we renovated our brownstone, we decided not to replace the windows, but instead to restore them. Our windows were in pretty bad shape, but the cost to restore them was similar to replacing them with high end Marvins, and we much preferred to have beautifully restored original windows than to replace them with generic new Marvins.
Regarding the glass, we replaced the single pane glass with double pane glass. The double pane glass was purchased from a manufacturer of Insulated Glass Units (IGUs), so they came fully prepared – low E gas, UV protection, warranty, etc. We even had some of the IGUs made with laminated glass to make them impact resistant so we wouldn’t have to put iron bars in front of our windows. My contractor “simply†installed the IGUs in the existing window frame. This involved custom woodwork for each sash.
It is important to note that double insulated glass is much heavier than single pane glass, so we had to change the counter-weights and weight pockets. That took some real calculations, but was straight forward. We also had to change all the hardware (chains, pulleys, latches, etc) to accommodate the heavier sashes and reduced space for the latches.
At the same time also we had the entire windows restored: all the moldings around the windows were removed, the sashes and frames were restored, the IGUs were installed, insulation was put in all around the windows, and we added interlocking bronze weather stripping on all sides of each sash.
We now have beautifully restored original windows that we adore, and which are wonderfully insulated.
Have a fine carpenter rout out the windows so they accept 3/8″ old wavy glass which is available as salvage, or 1/4″ store plate glass, or if you prefer, the double glazed.