55 questions, answered plainly.

Restoration keeps the original frame and sash, repairs what has failed, and upgrades performance components such as glass and weatherstripping. Replacement discards the entire assembly.

Repair addresses one failure. Restoration returns the whole assembly — wood, glass, hardware, seals, and finish — to a documented performance standard.

Most can. The deciding factor is how much sound wood remains in the frame and whether the profile can be reproduced.

Shop work is typically several days per sash, with cure times for adhesives and finishes driving most of the schedule.

No. Openings are secured with temporary glazing whenever a sash is out.

Far less than replacement. Interior trim, drywall, and exterior cladding stay untouched.

A properly restored and maintained wood window can serve for decades — many original assemblies are already well past fifty years.

Only by removing decay and failed finish. Sightlines, profiles, and proportions are preserved.

Shop work continues year-round; exterior finishing is scheduled around temperature and humidity windows.

Yes. The methods apply to any premium wood window assembly.

Usually, and the gap widens with unit size, custom shapes, and any opening that would require trim, siding, or interior finish work to replace.

When the frame has lost structural integrity across multiple members, or when the opening itself is being reconfigured.

Not in the wood. Modern glazing is better; old-growth timber is denser and more decay-resistant than most stock available today.

With Low-E argon insulated glass and rebuilt seals, restored units perform comparably at the glazing and often better at the frame.

Preserved original windows are frequently a selling point in architecturally significant homes.

Restoration scales to the failures. Replacement programs rarely do.

Compare scope by component: what is removed, what is milled, what glass package is specified, and what finish system is applied.

The perimeter seal of the insulated unit has failed and moisture is condensing inside the cavity.

No. Drilling and drying treatments do not restore the seal or the insulating cavity. The unit needs replacement.

Almost never. The sash and frame are usually sound; only the sealed unit is replaced.

A near-invisible metallic oxide coating that reflects radiant heat while transmitting visible light.

Yes, in combination with Low-E and warm-edge spacers. Alone, its contribution is modest.

A small annual loss is normal and has minimal practical effect over the life of a well-made unit.

Near doors, in wet areas, at stairwells, and below defined sill heights — code-driven and location-specific.

Adds safety retention, meaningful sound reduction, and strong UV rejection.

Original glass is retained wherever possible; restoration glass is available where it must be replaced.

A low-conductivity spacer that reduces heat loss and condensation at the glass perimeter.

Interior humidity meeting a cold surface. It signals indoor moisture levels more than glass failure.

No — it usually indicates the glazing is performing well and the outer lite is staying cold.

Slow growth produces tight rings, high density, and a much greater proportion of decay-resistant heartwood.

Quarter-sawn fir with rings roughly perpendicular to the face, giving superior dimensional stability.

Early decay responds to consolidants. Structural loss must be cut out and replaced with milled stock.

Selectively. Epoxy suits small voids; it is not a substitute for replacing a failed structural member.

By templating the original section and grinding knives to reproduce it.

Considerably. Mahogany and vertical grain fir outperform fast-growth pine in exposed conditions.

Sustained readings above roughly twenty percent create conditions for decay.

Yes. End grain and hidden faces absorb the most moisture and are the most commonly skipped.

Savings depend on the starting condition. Moving from single-pane and failed seals to Low-E argon with rebuilt weatherstripping produces the largest gains.

The rate of heat transfer through the assembly. Lower is better.

Solar Heat Gain Coefficient — the fraction of solar energy admitted. The right target depends on orientation and climate.

Predominantly at the meeting rail, the perimeter weatherstrip, and the frame-to-wall joint — rarely through the glass.

Yes, particularly with laminated glass and properly restored compression seals.

Interior storm glazing is an effective option for historic sash where the original glass must be retained.

Operation testing, seal compression checks, and documented glass specifications for every unit.

Exposure-dependent — typically every seven to ten years on protected elevations, sooner on weather-facing ones.

Clear weeps, intact finish film, functioning hardware, and prompt attention to sealant separation.

Mild soap and water. Avoid ammonia on coated glass and solvent contact with finished wood.

Yes. Compression seals are a wear item measured in years, not decades.

Soft wood at the bottom rail, peeling on horizontal surfaces, sticky operation, and interior condensation patterns.

Yes — annual cleaning and light lubrication of operators and hinges extends service life considerably.

Regionally, with shop-based restoration and field service coordinated per project.

Yes, though whole-home programs are more efficient to schedule and mobilize.

Every opening is catalogued with condition notes, scope, materials, and finish specifications.

Regularly, including on projects with review requirements.

Coverage varies by component — glass, wood repair, and finish each carry their own terms, provided in writing.