First, I think it's worth checking around the neighborhood to see what's common. If the neighbors have replaced all windows with inexpensive simulated divided lite windows, you won't gain much from a more expensive solution. On the other hand, if your neighbors have used wood replacement windows with real divided lites, it's probably best to do the same on your house.

I live in a town with an older housing stock, and a popular solution is to replace the windows that don't face the street with energy-efficient windows that have fewer or no lite divisions.

People usually keep the original windows facing the street, and either keep the original wooden storms, or replace them with paintable aluminum storms. If the windows require restoration, that's preferable to outright replacement.

In Texas we had the same problem and my husband restored 15 of the 21 double hung windows. We did not have a/c so it was great in the summer that they could open up or down. And since it was Texas, it wasn't so bad heat wise....it is easier to be hot than cold. I voted storm windows; but I have no experience with them. I just love old windows/glass.

I live in a 1929 bingalow where we too have the original windows. About half of our windows are leaded glass, so replacement is simply not an option. What we did was to get custom storms, in aluminum, in the same color as the window frames (in our case a medium brown). They work well, look amazing (especially since they replaced cheap off the shelf silver aluminum frames). The cost was quite reasonable--around $100.00 per storm (we have around 30 windows total), and while we may not get quite the energy efficiency, they did cut our winter heating considerably (we live in WI) and have already more than paid for themselves.

Being in somewhat the same position, budget dictates the solution. My 1920 home has leaky windows, and by leaky I mean the rain sneaks in. They are in really bad shape and restoration is not a cost effective solution.

To replace with mid-grade period windows I'd be looking at about $15K+ for my home. Fakey divided light vinyl windows would set us back about $4K+.

For us, I'm leaning towards the fakey, even though I despise them. I NEED new windows now though, and $4K fits the budget.

Do what you can afford. If you can afford replacement period wood windows - go for it!!

From personal experience, fibreglass doesn't hold-up at all ... It looks good for a few years, but then the colours start to fade and when you go to re-paint it just ... doesn't work. Real wood, if taken care of, can last years upon years.

Plus ... there's something about wood. It's always warm, no matter what the weather or conditions are.

Though, personally, I like the idea of keeping the original windows. Old glass is just beautiful.

In your shoes, I'd opt for storm windows. This is from George Nash's _Renovating Old Houses_ (our bible): "While the thermal performance of a refurbished single-glazed window fitted with a tight storm panel can never quite equal that of the best factory-made double-glazed windows, the difference is not so great as to merit the replacement of old windows solely for reasons of improved energy efficiency. The argument for new windows only makes sense when compared to the cost of doing nothing about the old ones or of paying a professional to improve them. Otherwise, you probably won't live long enough to amortize the investment."

Our old house did not come with its original windows. The owners before us inherited the house with bad replacement windows (just as drafty, but without the charm of leaded glass), so they went ahead and did what heather77 recommends, which is having simulated divided lights on the street-facing windows and just single panes on the back. It cost them a bundle, and it's nice having one fewer project to worry about in this house, but our windows are certainly not as charming as our entryway, which does have old glass and real divided lights. Consider yourself fortunate you get to make this decision!

There are other options besides those 4.

Anderson Windows (as well as others) make replacement sashes: Your existing window frame remains - only the sashes are replaced with new insulated glass panels. As long as your existing windowframes are in good condition and are square - this is a smart and cost effective solution, not only from the basic cost of the window but the reduced labor costs as well as being less invasive - You wouldn't have to replace the exterior and interior trimwork on each window, which can be a very costly project.

http://www.andersenwindows.com/servlet/Satellite/AW/AWProduct/awProductDetail/AWProduct/1135095639822/1102951372825?tab=1-3&tabname=Options%20&%20Accessories&tableftnav=Grille%20Patterns

Regardless of whether you replace the sashes or the entire window frame - They also have the choice of grilles installed in between the glass, inside removable grilles, outside removable grilles, fixed grilles, or both inside and outside permanent grilles with a spacer in between (The most visually-correct solution)

What you don't want to do is go cheap - This is your home and the windows are like the eyes. Plucking them out and replacing them with cheap blank hole windows without divided lites and thin/cheap moulding is never the right choice - It won't help your curb appeal or your resale value.

We have an older home, as well. Ours was built in 1932, so approximately the same age. We have energy efficient windows. They are fiberglass with a wood veneer with the simulated divided panes (with the "dividing trim" encased between the 2 pcs of glass) If you look around, you can find these though, admittedly, it was hard when we had a contractor break our window during inspection.
They don't look original (obviously) but they really look great and sure beat a cold room and drafts, anyday. Their biggest up side is, we have small children so there is no concern of lead in the paint especially when we open & close them (creating the lead dust that is inhaled). All of our moulding was replaced to original specs too.
All of those votes for keeping the originals don't have to live with that decision. I love charm as much as the next person but make your home comfortable, you can always add charm in decor! In my humble opinion, avoid replacing with the cheapest option because you may be cozy but will never be happy with the look.

I have forever coveted a log home near me (actually 3 log homes dogtrotted together), that the 2nd owners refurbished. They had lovingly restored all of the home's details including the beautiful original glass windows with all of their bubbles and waves. The next owners immediately replaced the windows. The home is not the same. Every time I drive by the windows stare at me with blank expression.
Keep the windows.

This is a hard question. Personally, I could get a good simulated divided light window because of cost and energy efficiency, but it sure would be a shame to get rid of the originals :(

I think it would be cool to create a green house with the originals, I've always wanted to do that.

You might want to look into interior storms, too. You can get them pre-made or make them yourself (if you're handier than I am).

I guess where you live is a factor (say Minnesota vs. Texas). Painted shut can be fixed and difficult to operate can be fixed -- they might just need new ropes.

I live in an 1872 house in New England. I have all original windows, and couldn't change them if I wanted to (historic district rules). But I have been replacing the storm windows -- I've gotten ones made by Harvey Industries of MA (some of my windows are the size of doors -- 82x36"), and they've made a noticeable difference.

I've also gotten honeycomb shades (from Symphony Shades, a VT company), that help a LOT with both heat and cold.

The shades ranged from $100 -- $200 per window, and the storms were from $200 -- $350 each.

We just went through this with the windows in our 1915 home. I learned a HUGE amount in the process! First, for anyone with an old house and old windows, I highly recommend Terence Meany's book "Working Windows." It's a wonderful guide to windows, regardless of what you decide to do at the end.

Next, look at your windows individually to find out what the issues are. If they're not fitting properly or are drafty, is there rot, loose or cracked glass, etc.? How bad is the damage? If it's minor, you can get older windows into shape pretty easily with caulk, replacing cracked glass, etc. if the basic window is sound. They won't be quite as efficient as modern double-paned windows, but they'll be a lot closer than you'd imagine. For most of our original double-hung windows, we got rid of the drafts by caulking and weatherstripping (I used spring bronze, but there are lots of easier modern types as well---all are DIY jobs). Weatherstripping improved the sound considerably, too. (We don't live in storm window country, but if we did that would be the very first thing I'd invest in.)

However, we had a few windows that had a huge amount of dry rot in the sashes, and no amount of weatherstripping was going to help with those. We replaced them with wood windows designed to look like the originals (but that function like modern windows, so they do have vinyl slides; for more money you can even get original double-hung sashes with ropes made, but that was way beyond our budget!) If you look closely, of course you know they're modern windows, but from a distance they look just like the original windows in the rest of the house. This was a great middle ground for us, and our drafts are gone except for two leaded glass casement windows that we're saving up to rebuild when we can afford the real deal.

For what it's worth, our city also has requirements for houses over a certain age, and would not have allowed many types of cheaper windows. So that's also something to check.

eek is what you say when you see a mouse,
eke is what you do to get by.

I live near Atlanta in a 1910 bungalow. Most of our windows are original. We've gone the storm window route, with less expensive double hung aluminum windows on the back and side that have been carefully painted to match the two-tone of the windows. The front windows will be storm picture windows. The storms have made a great difference in terms of drafts, but what made an even bigger difference is the in-wall insullation we've been adding this summer as part of our exterior rennovation. So far we have about half of the house insullated and the difference is amazing. We've saved what siding we could using a heat gun and removed the bad. When the walls are exposed we fish the pink batting up the walls - each section has to be cut to fit because of course no measurements are the same - the joys of an old house.

The other thing I'd say about storms is that they are a great crime deterrent. One of the ways criminals access houses is by shoving the flat end of a shovel under the lower part of the window and prying up and then snapping the sash. They can't do this with the storm. yes they can still throw a brick through the window, but that will 'hopefully" set off the alarm and slow them down.

It really would come down to budget. If you can afford it, and the building is architecturally significant to justify it, I'd restore the windows and look into the Slimlite double glazing for period windows (http://www.slimliteglass.co.uk/ ).

I live in a house built in 1790 in Boston. Some windows were replaced in the 30's and 40's but the front windows in the house are all original bubbly glass.
There are outside storms but it was still freezing when I moved in
I built indoor storms and they make a HUGE difference.
My heating bill went from $350 per month to $175. I did other things too, like put up heavy drapes with lining, but the indoor storms made the most difference.
Super easy to make too, I got my directions from google.

I'd keep the historic windows. Even the best replacement windows never wind up looking the same - always seem a little off to me in a historic house. Plus, with the windows properly repaired (a lot of which you can do yourself) and good quality storm windows, you'll get almost the same R-value. See this article from Fine Homebuilding: Should I replace my windows?

John Leeke at Historic Homeworks in ME has great how-to videos for window repairs you can do yourself.

Depending on where you live, there may be historic tax credits available to help you pay for the repairs and storms and other work on the house.

If that is your house shown above or yours is similar, I think you definitely want the appearance of muntins, if not the real thing.

I have a pet peeve with people thinking everybody ELSE should live in a museum. All the advice to "keep the old windows" seems to me to be a reaction against changing anything old. If that's your preference, by all means, go for it, but don't let the votes of people who will never see the house run your decision.

If your architecture and decor are traditional, I'd probably see muntins as contributing to the historical effect. But *I* would probably do it with new double pane "faux" muntin windows. My current home has the kind that are sandwiched between the panes of glass, from Harvey. (Vinyl clad.) Our old home had wooden structures that clipped within the frame to give that look, which was more three dimensional, at least from indoors. Anderson and Pella make really lovely options, but are more expensive.

Old glass has interesting imperfections, but it's brutal to actually SEE through. If you like it and want to live with it, again, that's your choice. I like to watch birds and keep an eye on the strange person idling in their car at the end of the cul de sac -- I want clear vision, thermal protection, no leaks, etc. not arty old panes, no matter how "blank" the "eyes" of my house seem to somebody who doesn't live in it!

If you are on the fence, ask a local real estate agent how your various ideas would effect the market value. If you have an authentic "historic house", as opposed to just an OLD house, different rules apply.

I love those large windows!

Do those windows need to open? They look like pretty special windows. I personally would opt for storms.

We frequently haunt our local Restore (Habitat for Humanity store) to see if we can find newer replacements. Maybe that is an option for you if you're not looking for an exact match.

I kept the original windows because I had to as they were landmarked. So we just installed awesome thermal pane modern windows on the inside of the house, so the look outside was historical, and inside was warm n' toasty. the windows were deep set so we had plenty of room to add the modern window on the inside. Plus it really helped magnify the thermal gain in the winter.

How true! A ‘window muntins’ protagonist now struggles between two radical “goods.” Either it’s true good looking (read: the real thing), authentic, replacement or, the “look” of true, authentic replacement for today’s world. Seems clear. The former doesn’t satisfy us today. Older materials can’t do what is required by our new energy and environmental consciousness. Renewed “old traditional materials” might “look” right, but at what cost to us and the planet? Green plastic window materials would lessen our environmental footprint and “look” right. Since both can “look” right, and one reduces our carbon footprint, this is a no-brainer. We want to increase the window light not increase our chores too: painting, de-molding, unsticking. The organization www.greenbuildingsolutions.org is a not-for-profit. We don’t sell windows, but it’s clear that vinyl windows can have a specific historical look no matter the age, be virtually maintenance free, open easily, never need painting, and, you get a thermal break between the family and the holiday snowstorms outside. Plastic green building solutions can reduce our energy use and the associated heating and cooling energy and pollution. Check out: http://bit.ly/bQgTnG .

Surprised that vinyl windows are not offered as an option on the survey. Vinyl windows represent more than half of the total windows sold in the U.S. (25.5 million in 2009).

Vinyl windows are among the most energy efficient (www.nfrc.org) and have the design flexibility to ressemble their historical ancestors.

For more information on the performance and structural attributes of vinyl windows:
Visit Green Building Solutions’ Website
Visit AAMA’s Website