A capable remodeler installing windows today is far more likely to insulate the rough opening around the new window with an air-impermeable material than with the old standby: stuffed-in fiberglass insulation that allows air to move through it relatively easily. He is also more likely to understand what sill pan flashing is and the correct protocol for installing flashing tape on a window with integrated flashing flanges.

Such air and water management is essential in home performance, but we need a more comprehensive definition to bring all the parts of home performance together. I propose the following — but read carefully; every word counts!

“Home performance” is the science and practice of building and improving homes according to a comprehensive package of measures that make the home as safe, comfortable, efficient, and durable as possible.

Each home is a distinctive system involving the building itself, the mechanical equipment, and the occupants.

A home performance professional understands and addresses the subtle interactions of the components of the house as a system and considers, at every step, that a change to one part of the system can (and almost certainly will) have an effect on the other parts.

The remodeler who uses spray foam around a window or a door is borrowing one technique from methods of home performance, and this is a good thing. But home performance contracting meets the complete definition when a project’s scope of work anticipates and guards against possible problems and maximizes available benefits by recognizing that the house is a system.

When you change a window, it’s possible to do an excellent job, and it’s also possible to screw it up. In the end, however, it’s just a window.

If, on the other hand, you change all the windows and doors and air seal and fully insulate the house but leave the 1980 furnace, or you don’t add effective bath fans or a rangehood, you could set the stage for problems ranging from moisture issues to increased radon levels. Understanding the house as a system solves problems in the short term and avoids future problems. That’s home performance.

Ed Voytovich, now retired, is a 40-year veteran of the remodeling and energy-efficiency industries.

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