The Situation
1) old traditional adobe house in NM with 14 windows that ain't working too well
2) windows are all wood (int. and ext.), single pane, double hung. Each sash contains only one vertical mullion - so two lights per sash.
3) we considering all wood replacement sashes with dual pane, low-e glass and would like to stay as true as possible to look and feel of original windows.

The Dilemma
1) architect (accomplished, reasoned, tasteful, and definitely not pushy) insists we will do ourselves and the house an injustice if we don't stick with True Divided Light on the replacements. He realizes the dual panes will require a 1.5" mullion in order to hide the spacer bar in between. He says it won't matter, seeing as how there is only one vertical mullion per sash and the windows are fairly large. In his opinion, Simluated Divided Light would make an undesireable aesthetic difference in the way light is diffused through this particular house.
2) Window dealer says architect is coo-coo. That we would never be able to tell the difference, and that the expense ain't worth it. (Besides, his company doesn't make dual panes with TDL, though I have found others who do.)

The Questions:
1) Can anyone describe for me the subtleties we're talking about? What are the aesthetic characteristics of TDL vs SDL?
2) Does anyone own TDL windows with dual panes? Are there risks involved with the durability and integrity of such windows?
3) Will I notice a big difference in the color and quality of light coming through once we switch to low-e glass (as opposed to single pane clear)?
4) Is there a bigger nightmare than remodeling a house? Geez.

Well, the answer to the TDL v SDL question is easy. In true divided lights -TDL-each pane is installed in its own frame that goes clear through the window. In SDL there is some sort of grille appplied to one surface of the glass, or worse both surfaces, but there is only one pane of glass, so when you look sideways at any angle but dead on you can see the fakery. If I couldn't have TDL, I'd change to a different muntin pattern. You architect is correct, there would be a significant aesthetic loss. Especially since you don't have have that many muntins, in the first place. I'd economize elswehere to make sure I could have TDL.

However, before I'd exchange the original older windows for modern ones, I'd look into getting them brought up to good consition, adding wooden storms, etc. This is often cheaper than quality replacements. (Though maybe not so much $$$ for the architect....) You could be saving original stuff and getting excellent energy improvement at the same. Problem is finding someone to do this work in your area. I have just located someone near me to work on my own windows, and delivered four there yesterday for an initial project to see how this worker does. If you keep asking around I think you'll turn up somebody. I found the guy I hired yesterday by keeping my eyes peeled for years and asking around all the time. When I saw a window in at the hardware store awaiting measurement for a reglazing, I recognized it as something that was being rehabbed. I looked it over carefully, and noted the contact phone number on the sash, and scurried home and called it. Turns out my guy does it all the time, but is so busy he never advertises. My advice: keep asking till you find the local version of my window genius.

Molly~

Housekeeping - thanks for the helpful post. It seems like I have been researching this window stuff for a long time, but I guess I just need to stay the course until we find the right dude (or dudette). I'm encouraged that your persistence paid off.

Skywagon185--

I recently ordered a great book (Colonial Style by Treena Crochet) and she had this to say about how to construct "perfect storm windows":

"There is an aesthetically pleasing way to add storm windows to historic homes without having to resort to the aluminum, prefabricated kind. This resourceful homeowner first designed a special frame to fit the outside dimensions of the window. Next, the frame was divided into an upper and a lower sash, matching the alignment of the sash of the interior window. The frame was then attached to the top of the window with hinges, leaving the bottom open for an easy escape in case of fire. A wrought-iron handle was added to the frame, making it convenient to transport it to the cellar for storage."

There is a small picture, and it shows the storm window virtually resting (maybe not quite) on the exterior window sill. There is a wider margin of the existing window frame that is exposed at the top and on the sides. The horizontal board that divides the storm window is located at the point of the interior window sash that divides the nine over nine panes. Two hinges are attached at the top and the slender, vertical wrought iron handle is secured on the left just above the horizontal board. The unit is painted white to match the existing window trim. It is a very good looking storm window!!

I would include the picture, but I haven't figured out how to do that yet. I hope this helps.

We are restoring an 1880's farmhouse and have run into some issues with our windows. The drafts upstairs are so bad that you can hear the wind whistling through the rooms. We plan to move in this October after our wedding and would like to get these insulation issues taken care of before then. Is there any way some one could give me an idea of the cost of custom storm windows. Our windows are beautiful... they're oversized with all the original moulding and glass from the time period and we wouldn't replace them for anything! We have eleven single windows and two doubles that overlook the front porch. I just don't want to get taken by someone because we don't know what to expect!

You can maintain the integrity of the original windows and get an upgrade in efficiency by refitting your sashes with insulated glass. They did this awhile back on an episode of This Old House. They also upgraded the balances and eliminated the sash weights and insulated the empty pockets.
Ron

If you can build (and easily install) exterior storm windows, then you might want to build the storms with insulated glass. I did for most (ongoing project) of the double hung (not really, a piece of spring holds them up through friction) windows on my 18th century house.

I used full size insulated 3/4" glass in 5/4 lumber and trim pieces to hold the glass in place

I still have to swap the storms for screens or vice versa twice a year, but they allow me to use top and bottom style window openings during temperate weather.In my case (single story stone house) the swap isn't a problem - but the weight might be a problem up on a ladder on a windy day.

Aesthetically, the single panes are not noticed because the 6 over 6 panes of the sash are clearly visible - the storms are almost invisible - need to measure better!

We had ours totally rebuilt.downstairs are 9/6 window panes.with the bottom half screen (removable)Then we had storm window one piece of glass,with piece of wood 1/2 down.It has clips at the top then on bottom pins you pull and they snap in a hole in trim.Upstairswindows are 6/6.old wavy glass.We had 24 windows total.