Wood windows, aluminum windows, vinyl windows, fiberglass windows and hybrids of all the above -- there are a lot of options to consider when you're buying windows.
The most basic consideration (right after you answer the question, Can I really afford this?) is how you want the windows to look from the street.
If your house is in a historic area, or you just want to do the most historically sensitive job possible, you are probably going to have to use wood windows that can be painted to complement other visual elements of the house.
Wood windows come in two basic forms. One is wood sashes made up by your local mill to fit existing frames, or to fit replacement channels. This is a relatively inexpensive route, but there are a few problems. For one thing, the sashes tend not to fit very tightly into the channels (old or new), so they're not energy efficient. You can add storm windows (on the inside if you're preserving the outside appearance), but you really need two tight surfaces with a dead air space between. If either the sashes or the storm window leaks, condensation will build up on the coldest surface.
The second basic form is a factory-built window system. There are a number of major brands -- like Marvin, Andersen, Pella, Certainteed, Wenco, Weathershield, Pozzi, Kolbe & Kolbe. Some these are available through lumberyards and home improvement centers, and some are available only through factory distributors (though still at retail).
Many of these manufacturers offer two replacement options. There are window-replacement systems that replace the whole window and jamb. They come in a wide variety of sizes and shapes, though they may require altering interior and exterior trim to get a good fit. The other system, the sash pack, consists of replacement sashes and factory-made jamb liners that provide a tight fit. The sash kits leave existing trim alone and are energy efficient, and like the full-window replacements, come in all-wood or exterior-clad versions.
Bill Mold, owner of W. F. Mold Inc., a window, door and millwork distributor in Rosedale, suggests that prospective window buyers ask themselves a number of questions -- and then take the answers to the dealer.
*Do you like the look of wood inside but want a maintenance-free exterior? If the answer is yes, you should order windows with vinyl cladding on the outside. However, if you live in a historic district, or want historical authenticity, don't even think about vinyl on windows visible from the street.
*Do you want replacement windows or sash packs? If you're not disturbing the trim, an experienced carpenter can install sash packs in about 45 minutes. If you replace the entire window, you can still replace the trim with something reasonably historic, but this is a more expensive solution.
you want the window flush with the inside wall, or do you have unusually thick walls that might cause trim problems with a standard-thickness window? Most factories will make windows with thicker jambs.
*Do you want true divided panes, or a single pane that can be modified with a "snap-in" grid? Single panes can be insulated; true divided panes will need separate storms and screens.
*Speaking of screens, do you want full screens or single sash screens?
*If the windows will be wood inside, will they be painted or stained? If you're going to keep the wood look with stain, bronze hardware might look better. If you're going to paint, white hardware usually looks better.
*Do you want to invest in special glass? Mr. Mold cautions window-shoppers to check out manufacturer's claims for glass with special insulating properties, such as "low E" glass. In his opinion, it's an expensive option that's more useful in especially cold or especially hot climates.
The things that make a window thermally effective, Mr. Mold says, are wood, weatherstripping and double glazing. "Wood is a real good insulator," he says.
He also warns people not to be influenced by energy "ratings" manufacturers give their windows. Though the National Wood Window Manufacturers Association is working on developing national standards for window efficiency ratings, no such standards exist yet. That doesn't mean manufacturers' claims are false, but it does mean they can't be compared, because they may be based on different criteria.
"Look at how the window is constructed," Mr. Mold says, "not at the rating."
*Who will fix a window if it breaks? Some windows are much easier to repair than others, Mr. Mold points out; pay attention to ease of repair before you choose a window.
Next: Air handling without air conditioning.
Mr. Johnson is construction manager for Neighborhood Housing Services of Baltimore. Ms. Menzie is Home Editor of The Sun.
you have questions, comments, tips or experiences to share about working on houses, write to us c/o HOME WORK, The Sun, 501 N. Calvert St., Baltimore, Md. 21278. Questions of general interest will be answered in the column; comments, tips and experiences will be reported in occasional columns.