Windows in New Hampshire meet very different weather within one state. Seacoast sash takes salt and wind-driven rain. Mountain houses collect ice on the sill and condensation when a wood stove loads the air with moisture and the night drops hard. Lakes camps often still have single glass and storms that do not latch. Valley double-hungs rattle because the openings have settled. Say which of those houses you have.
A soft sill, fallen putty, and a snapped cord are separate repairs. Storms that trap moisture against the prime sash rot it from the outside in. A stock unit jammed into an old opening foams up and then leaks at the foam in the first serious rain. Look at the apron inside. The brown line means the water is already past the glass, which is common on the ocean side and on any wall that takes the prevailing wind.
Fog between panes is a dead seal. Sweat on a single pane may be cooking, a shower, or a damp crawl under a camp, not a reason to replace the wall of glass. Large cold windows in an older house will always feel cold in a mountain night. That is not the same defect as a rotten stool. Know which complaint you have. Brick and post-and-beam openings are often odd sizes.
A window that must remain a way out of a sleeping room has to work after the work. Shutters and storms are part of the description. Weights and pockets are worth keeping if the wood is sound. If a key sinks into the sill, the opening needs more than a cord. Exposed Seacoast paint fails faster. Mention the exposure so the repair matches the wall.
List the bad openings and the rooms. Say repair or replacement, and name storms or bays. Have the town and whether the house is camp, cape, or village. Call the number on this page.