When a window stops working right, the first recommendation is usually replacement. Window replacement is a high-margin product category — sales reps are trained to sell new units, not repairs. This article gives you the other side of that conversation.

What Replacement Actually Costs

A vinyl double-hung replacement window runs $300 to $800 for the unit itself. Installed, with labor and any necessary trim work, budget $600 to $1,200 or more per opening, depending on size and the condition of the surrounding frame. For a house with 20 windows, that is $12,000 to $24,000 — or more.

Restoration of an existing historic window, depending on condition, typically runs $100 to $400 per window. A window with moderate paint failure and a broken sash cord is on the lower end. A window with significant rot in the sill and bottom rail — requiring epoxy repair and full re-glazing — is on the higher end. The cost difference over a whole house is substantial.

The Wood Quality Argument

Pre-1940 windows in Louisiana were almost universally made from longleaf pine, a species so dense it will turn the edge of a pocket knife. This wood grew slowly in old-growth forests; its growth rings are tight and its resin content is high. Water and insects have a hard time with it.

The framing lumber in a new replacement window is plantation-grown pine — fast-grown and porous. It does not have the same rot resistance. Vinyl windows avoid the rot problem but introduce their own issues: they expand and contract aggressively with temperature, they cannot be repaired (only replaced), and they have a service life of 15 to 25 years before seals fail and glass fogs. A restored original window, properly maintained, should last the life of the house.

The Energy Efficiency Comparison

Replacement windows are sold heavily on energy efficiency. The actual performance data is more nuanced.

A single-pane historic window by itself performs at roughly R-1. Add quality weatherstripping and an interior or exterior storm window, and you reach R-2 to R-3. A standard double-pane vinyl replacement window is also R-2 to R-3. The performance gap is smaller than the sales pitch implies.

The Department of Energy and the National Trust for Historic Preservation have both published studies confirming this. Weatherstripping and storm windows on existing historic sash is a cost-effective path to equivalent thermal performance — at a fraction of the cost of full replacement.

What Gets Lost With Replacement

Original historic glass is hand-rolled or drawn glass — it has subtle waves and irregularities that give old houses their characteristic quality of light. A small number of specialty manufacturers still produce it — Bendheim sources mouth-blown cylinder glass from Germany, and Restoration Window Glass produces it domestically — but at $28 to $43 per square foot or more, versus roughly $12 for commodity glass, the cost puts it beyond most residential budgets. When you remove original historic glass, you lose something that cannot be practically replaced.

The proportions of historic windows were designed to the house. Replacement windows come in standard sizes that often do not match the existing opening exactly. Installers shim and fill the gaps with casing, and the result rarely looks quite right on a period home.

Historic Tax Credits

If your property is individually listed on the National Register of Historic Places, or contributes to a listed historic district, removing original windows can disqualify you from the federal Historic Tax Credit (20% of qualified rehabilitation expenses) and the Louisiana State Historic Tax Credit. These credits have real dollar value. A preservation-focused restoration contractor can document work in a way that supports a tax credit application; a window replacement contractor generally cannot.

The Bottom Line

Replacement is the right answer in specific circumstances: the original windows are completely beyond repair, you are not in a regulated historic district, and the budget is available. In most other situations — especially on pre-1950 homes in Baton Rouge — restoration is better on cost, better on performance, and better for the character of the house.

If you are weighing the decision, the first step is an honest assessment of what your windows actually need. "Replace them all" is rarely the right starting point.