Just to be honest, I'd say your home falls into the fringe of this group--but if you think the style is significant--then I'd fix the windows which are there; if you can find an EXACT match for them, then you could do replacements--but repairing the present wood ones will be cheaper.
No matter what sales people say, replacement windows take decades to recoup any savings from the initial cost.

If you consider this home to be historically significant, scrap the idea of AL or fiberglass clad. As columbusguy said, repair the existing windows.

Pictures wood probably help. If they are a Woodco Window or similar type product probably not worth repairing, but a brand may help as well as pictures.

That window design is one of the many reasons I am glad the 70's are long gone. Don't be influenced by what the architect thinks of his design, of course he loves it. Obviously, I would look for any excuse to replace the windows but then I haven't seen the house. It's really difficult to offer design advice based on a short written statement. Am I wrong to think you are not in love with the house since you did not give us a photo?

I'd love to see a picture of the house.

Thanks guys. Shame on me for attempting this without pics. I just cant get the image to display in the message whicgh annoys me greatly. I started a photobucket account and everything

.

Ok, link to album..

This home was designed by David Lyons. Its located on Signal Mounatin Tn (chattanooga). It overlooks the TN river and Williams island which was once a French Indian trading post.

The windows are Pella. On closer inspection I realized that they technically are not Insulated glazed units. The inner pane can be removed(see interior pic). Interesting.

Here is a link that might be useful: Album of home and windows

You must restore them I'm afraid if you can't replace them with the same wood. They are in a highly visible spot. And it's a WOOD house. (And a lovely one--don't let anyone tell you it's not old enough to be good!)

:)

Wood. Gotta be wood.

Were I to go to the trouble to replace them, it wouldn't be in wood. If you need them in a custom color, you can get them made to match in a clad widow. Wood was probably an economic solution in the 70's; they are really attempting to emulate commercial glazing with that proportioning. The style of window with a larger plate and an operable section beneath goes all the way back to the beginning of the "international style".
Casey

It hurts me to say this because I am so miserly, but this may be a time to work with a firm with some architectural preservation experience. yes you will probably spend more than if you spec and order your own windows and get some random installer off Angies list, but in a case like this, working with a pro will get the look "right" on the first try, and when it comes to windows, paying a premium for professional consulting is cheaper than multiple attempts at getting the right look. Casey is too modest to toot his own horn but he's a professional arch. pres. so you can weight his advice accordingly (and my apologies to anyone else posting helpfully whose credentials I've missed).

your house is COOL and I'm glad you're on the forum. One of the things that makes older houses special is that some of them were custom-designed with the site, views, path of sun, etc. in mind. Your house totally fits that criteria, even if it's not that old yet. If you get around to adding any more photos, especially interior, we will gladly gobble them up.

Ouch.

All for lack of painting.

The problem that keeps showing up with clad windows is that the seal between the cladding and the wood eventually fails, water enters, and concealed rot starts to work.

At least with plastic cladding the joints can be 'glued' ('solvent welded' is a better term) to provide a better seal than aluminum butt joints and some type of sealant.
The sealant WILL fail, the joint WILL leak, and you will not see the damage from the inside till it is serious.

Wood windows require periodic painting, but a good paint job should last at least 10 years or more.

Thank you all! Full disclosure, this is my parents home. Iam a home builder who focuses on new construction and I am inexperienced with historical preservation which is why Iam here. Slateberry, thanks for the recommendation but I dont feel its quite the right fit for a consultant. I could probably get an exact match if me or my parents wanted to but budget and time are limited, its not a famous house, and the desire to be perfectly, historically correct is not there. We are after more of a balance for less maintenance in the future.

Casey, thanks so much for referencing the international style. Also good to hear that my thinking of going with a clad product is recommended by someone with so much more design and historical experience. The existing color is a very close match to most companies standard dark brown color offering.

Brickeyee, are you really recommending vinyl here or saying you think vinyl windows are longer lasting than clad products? I probably wouldnt go with it just from the color restrictions alone but my thinking was that clad products are longer lasting than vinyl. I thought the expansion/contraction characteristics made the welded or fused corners fail(even the high end lines). I suppose that the newer fiberglass FG clad products would suffer from the same weaknesses? Given that FG and glass have nearly identical expansion and contraction rates so the joint sealant should last longer...

I think 10 years would be the absolute max life span given the windows exposure and would suffer from failing sealants as well. At least by pulling the windows out frame and all I could build a durable sloping sill pan which would protect the framing below. I am theorizing that even a clad product would have a longer lifespan with no maintenance needs as compared to painted wood that would need stripping and painting every 10 years or less. The clad product's joints might fail but the framing below would be protected and I imagine the wood below the cladding could dry out well enough between wetting events or if not the cladding would hold everything together for a very long time.

My position is obviously solidifying but would love to hear other opinions.

I'm a preservation carpeneter, etc., but not an architect. I design woodwork, not bldgs.
Casey

And you wouldnt be offended by a unique home with mostly wooden elements yet switched to a synthetically clad window in a particularly vulnerable location?

Let's ask the original architect. His judgment should carry more weight than anyone else.
Personally the macro idea of the house being allowed to age gracefully while becoming more efficient and less rot-prone and keeping the style of fenestration in a more weather-resistant material represents a compromise/cost/value balance that I think a preservation-minded individual would be happy to see. The original widows, as I posited earlier, would have easily been rendered in a commercial anodized aluminum glazing system and been just as true to the overall style of the house.
Casey

Personally from my end I would look into replacing the units with an extruded aluminum product like a Fleetwood, Arcadia or Solar Innovation product. Thee will allow the larger pieces of glass with narrow site lines like you have now yet be pretty much maintenance free, Here on Long Island waterfront homes are built all the time with similar appearing units from the above manufacturers. I am not saying only these brands nor am i saying any of these are great just throwing some recognizable names out there. If it were my house I would look into Arcadia or Solar Innovations (personally not a Fleetwood fan). But I would think an aluminum extruded Architectural product would be the way to go.

Would be interested in seeing what and how things turned out 8yrs later... any updates?

We are in the same events with a home cared for by her owner, built in the early 70s, wood windows and great architectural style for our neighborhood. How did things end up? What would you have done differently??

Another two years from the last comment, and I've arrived in the same situation. Buying a home from 74' that has a wall of wood framed windows, floor to ceiling, six panes, going up to the angle of the ceiling/roofline. The home inspector recommended repair or replacement within the next few years. I would love to preserve the wood framing, but this comes with increased complications.