Rick Bonasch wrote an interesting post on wooden window restoration for STL Rising.
What do we think about keeping old wooden windows?
Our house has seventeen window openings. Originally, the front four windows were one-over-one while all others were two-over-two. One previous owner replaced the four third-floor windows with decent aluminum one-over-one windows that fit the existing openings pretty closely. The next owner had a fire in the house and ended up replacing eight windows with ill-fitting one-over-one white vinyl windows, two of which are on the front elevation. This owner did not maintain the historic wooden windows, which have problems.
Our plan? Retain the aluminum windows for a few years, since they provide good insulation, fit the openings well and are barely visible from the street. I will restore all of the wooden windows myself except for the two on the back wall; the plan had been to start this fall but with a back staircase that needs major repairs I'll likely not get started until the spring. The back wall is going to be taken down and relayed, so it's easier to install new windows there. We are using custom-order double-pane, low-E Marvin windows that are solid wooden two-over-two units with authentic dividers. This is a southern exposure, so the new windows make sense in terms of energy conservation. For the openings plugged with vinyl, we will be removing each one and replacing with other authentic wooden Marvin windows like the others, except we will be using their "Tilt-Pack" model designed to fit existing jambs. This replacement will take place inthe spring if we ever close on our loan.
The Marvin windows may upset purist readers, but they were actually recommended to us by a rehabber in Old North who used them on his house, which he and his wife restored to near-exact 1879 appearance. At between $500-600 an opening, the Tilt-Pack units are a lot more affordable than authentic milled replicas, which can run upwards of $800 for sashes before hanging and glazing. they are also easy for a novice like myself to install, so I won't have to pay anyone to hang them for me. The added energy efficiency is a huge bonus; we won't need storm windows on them. Best of all, they will look very close to the original windows, and be real wood on the interior and exterior, so our own purist hearts will be placated.
Now, mind you, if all seventeen openings had their original wooden windows, the plan would be to restore each and every one of them. Since that is not the case, we are choosing to balance historic appearance, cost and our time -- and still get real wooden windows.