y the end of his three-hour visit, Page has gotten stuck in a ceiling hatch, tearing off the molding and covering his backside with plaster dust (they made these things smaller back then, he says in a muffled voice, his upper body still jammed in the attic as he tries to steady the lower half of his six-foot frame on a wobbling ladder); shimmied through storage spaces on his hands and knees (in one of them, next to a box of Christmas ornaments, he spies a duct that's been leaking hot air into the attic); reversed the spin direction of the fan that hangs from the cathedral ceiling in the living room (for better heat distribution); and set up a giant fan in the front door to suck all the air out of the house. This last part, called the Minneapolis Blower Door Test, is an add-on that costs an extra 75 bucks and involves a large fan suspended in the middle of what looks like the frame of a storm door, shrink-wrapped in red nylon and outfitted with enough dials to command a submarine.

The blower door test was devised in Minneapolis (no surprise there) in the early 1980s, when energy efficiency made its first appearance in the public consciousness. It measures energy loss in terms of how much air is exchanged between the interior and exterior of a house. Page takes several minutes to assemble the contraption and wrestle it into the door frame while Katie bemoans the drafty stone fireplace and the rate at which the family has been using heating oil. Page chuckles; he expects high readings on his blower door gizmo. "It's quite common for this to detect leaks that I've missed," he says, fiddling with dials and jotting down the air pressure in the house. Before he turns on the fan, he tells Katie to cover the fireplace ashes with newspaper while he shuts off the furnace. Katie glances anxiously at her white couch.

Clipboard and pen in hand, Page flips the switch. The large fan whirs loudly, sucking air out of the house; the change in pressure is noticeable. He marks down a couple of readings. With the fan still blowing at top speed, Page leads Katie around the house like a blind man, running his hands along windows and walls, hunting for drafts. There are many: Cold air streams in along the joints in the brand-new windows, between the pine planks in the cathedral ceiling, around the original metal-frame windows in the babies' rooms, around the doors that lead to the garage and to the attic -- even from the recessed lights in the newly remodeled kitchen.

he UPS man arrives as Page is disassembling his contraption. Tiki, the family dog, is running around with a ball in his mouth. The babies are crying. It's hard to imagine there's much time for home improvement projects in this busy household, but Page's initial suggestions are reassuringly simple: Apply clear caulk between the tongue-and-groove planks in the ceiling and along window joints; place foam sealant in the gaps in the floorboards around the pipes that lead to the sinks and Jacuzzi; add weather-stripping and an extra layer of insulation to the doors that lead to the attic and old darkroom upstairs. (Page also mentions drapes for the picture windows, but Katie either doesn't hear him or doesn't want to. He later says that most people aren't willing to make aesthetic changes if they can afford not to.) Page gathers up the last of his gear and promises to send along a full report.

More than half of all energy used in the average home is spent on "conditioning" -- heating and cooling interior spaces. About 15 percent is used to heat water, 6 percent to refrigerate food, and 25 percent to run other appliances. Of all the energy wasted, about one-third is lost through windows and doors, and the Abstoss home is no exception. All of the rooms have picture windows, many of them single-pane glass in metal frames. Single-pane glass is a poor insulator, and metal frames actually conduct cold into the house. Double-pane glass has twice the insulating power, and wood frames are best at keeping out the cold. (Vinyl is a pretty good alternative -- and much cheaper.)

The report that arrives a couple weeks after Page's visit indicates that Katie and Nick will quickly see a return on the improvements he has suggested. The packet includes do-it-yourself instructions for the simpler caulking and insulation projects as well as Page's recommendations for an Energy Star-rated programmable thermostat, reliable home-heating contractors, and the name of a company that will make a glass door for their fireplace. Katie and Nick also learn they can add inexpensive storm windows to their existing frames rather than replace the windows altogether. It will cost them about $800 to implement all of Page's suggestions, but by doing so they can expect savings of nearly $400 a year. Not a bad deal -- and spring is already on its way.