The Wood Itself
You may be surprised to learn that not all wood was created equal

The stock for wood products that were milled before about 1930 were harvested from "virgin forests," that is, forests that grew naturally and slowly. By the 1930's, though, this first-growth wood had all been used up. To supply our need for timber, "wood farms" were created. Trees in these farms are fed hormones to speed up their growth. As with most things in life, though, this haste has come at a price--the loss of quality and durability.

Wood from virgin forests is, first of all, much stronger than farm-grown wood. Its slow growth has enabled the development of tight graining, which increases its strength. This fineness of graining also contributes to the superior aesthetic quality of first-growth wood. Because of the abundance of first-growth stock, craftsmen were able to select wood for window construction that was clear and free of knots. This abundance of stock also afforded the manufacturing of thicker frames than are manufactured today. All these factors have resulted in windows that are highly durable. Finally, first-growth wood is more absorbent than second-growth wood, enabling it to absorb paint and stain more easily and evenly than does second-growth wood.

The Craftsmanship
Original windows are put together with mortise and tenon joints, the best possible joint for windows. When these joints are restored, the window will not wrack or warp. It will stay square for years. Joints on windows today are put together with inferior, machine-made finger joints, or other styles, and are typically stapled and glued together. Original windows were built right into the wall, carefully integrated into the architectural design. Once disturbed, this fit cannot be recovered.

Original windows have an irreplaceable distinction that newer, mass-produced windows lack. Notably, many of the most interesting profiles are no longer milled and can only be reproduced by hand-tooling or by creating new knives to match the old profiles (an expensive endeavor). Reproductions of older windows inevitably leads to the simplification and downsizing of the original design.

The Mechanism
The weight-and-chain balance system of 19th century window mechanism remains (when measured in the long-haul) the most durable and workable system for historic windows. Newer spring systems may work fine when first installed, but their life expectancy is a fraction of that one can expect from restored weight-and-chain balance systems. In addition, the weight and chain balance system has a graceful charm that is aesthetically pleasing and appropriate to older homes.