How does restoration affect the value of antique furniture?

It depends on what was done and how well. Sympathetic, reversible repairs, like regluing a loose joint, replacing a missing knob with a period-correct match, or stabilizing a cracked veneer, usually help a piece sell because buyers can use it with confidence. Heavy-handed work tends to hurt: stripping and refinishing, replacing large sections of wood, swapping out original hardware, or cutting a piece down to a new size.

For high-end, rare or signed furniture, collectors want as much original surface and construction as possible, so even good restoration can lower value. For common, decorative furniture, buyers care more about condition and looks, and a sound, attractive restoration may raise what it brings.

If you are planning to sell, it is often wise to ask an auctioneer or appraiser before restoring. Sometimes the best move is to sell the piece as found and let the buyer decide.