Andersen Big Doors: Specs, Testing Data & Idaho Fit

Specifications & Testing Data

What Andersen Big Doors Actually Are

"Big Doors" is Andersen's name for its Architectural Collection of moving glass walls — door systems where an entire wall of a room opens. Three of them make up nearly all of what we quote in Idaho. The MultiGlide is a multi-panel sliding door where every panel rides its own track and stacks to one side or disappears into a wall pocket. The Folding Outswing door is a top-hung bi-fold whose panels accordion out of the way. The Liftslide is the premium slider: turning the handle lifts each panel off its weatherstrip and onto rollers, then sets it back down sealed when you close it.

All three are built as aluminum-clad wood by default — wood interior, extruded aluminum exterior — and the Liftslide is also offered in all-aluminum and all-wood. They sit above the 400 Series and E-Series patio doors in Andersen's lineup and are sold through a shorter list of dealers because they need real engineering on the receiving end.

MultiGlide, Folding Outswing and Liftslide, Side by Side

The trade-off the table hides: folding doors give the largest clear opening when open but need more, narrower panels, so when closed you see more frame and less glass than a slider of the same width. Pocketing gives the cleanest look but requires a wall cavity deep enough to swallow the panels.

The Numbers That Matter

There is no such thing as a cheap 20-foot glass wall in a cold climate, and the energy math is honest about it. Andersen publishes NFRC ratings per configuration, and the whole-unit U-factor on a big door depends on panel count, glass package and whether you order the thermally controlled frame. We run the numbers for your exact configuration and compare the wall's heat loss to what the solid wall and slider it replaces were doing. On a well-specified triple-pane MultiGlide the result is often better than the old wall-plus-slider combination; on a bare-minimum dual-pane bid it is not, and we'll tell you.

The performance grades matter in Idaho too. A PG30 rating means the door was tested for structural load, air and water at pressures equivalent to roughly 110 mph gusts — comfortable for most valley-floor lots. Flush-sill units are unrated for water, which is the honest reason we steer exposed installations toward the on-floor drainage sill.

Headers, Pockets and the Builder Conversation

A big door is a structural project first and a door second. Spanning 16 to 24 feet in a bearing wall means an engineered beam — typically LVL, PSL or steel — sized for the roof and floor loads above it, posts and footings that carry that load down, and shoring during framing. Pocketing doors add a framed cavity beside the opening that has to be plumb and dead-level, because the tracks are pre-assembled and don't forgive a bowed stud. Andersen's frames have built-in jacking screws for fine adjustment, but they adjust an eighth of an inch, not an inch.

On new construction in the Boise foothills, Harris Ranch, Avimor and the custom lots around Eagle, we coordinate directly with the builder's framer and engineer: rough opening dimensions, pocket depth, sill recess for a true flush floor, and the sequence so the door goes in after the roof is dried in but before flooring. On retrofits we bring the engineer.

Snow, Ice and the Sill Track

Idaho asks one question of every flush-sill door: where does the snowmelt go? A flush track sits 3/16 inch above the finished floor. Snow that blows against the glass melts on a sunny February afternoon and refreezes at night, and a track full of ice is a door that doesn't open. Andersen's answer is the drainage sill with built-in channels and interior and exterior ramps; ours is a sloped, fully sealed pan under the entire track, weeps kept clear of decking, and a patio surface that steps down at least an inch from the interior floor. Heat cable in the exterior sill zone is a reasonable add on north-facing walls.

Where Big Doors Fit in Idaho — and Where They Don't

The right house for a big door is one with something to look at — foothills, the Boise River, a Bogus Basin ridgeline — and a wall that faces it. The wrong house is one where the view is a neighbor's fence, or where a 16-foot west-facing wall will turn a great room into an oven every July evening no matter what glass is in it. Deep overhangs, SmartSun glass and orientation are design decisions that have to happen before the order.

Sometimes the honest answer is a 4-panel 400 Series Frenchwood or E-Series gliding door instead: at 12 to 16 feet it covers most openings for far less, with a conventional sill. We quote both when the opening allows it.

Warranty and Service, Locally

Andersen's Architectural Collection doors carry their own limited warranty documents rather than the standard 400 Series terms, and the MultiGlide automation system is covered by a separate five-year limited warranty. We walk through the exact document for the door you choose before you sign. Service is ours: Wood Windows Inc has installed and adjusted doors in the Treasure Valley for 46 years with employee crews based in Garden City, and a big door's rollers, weatherstrip and alignment are serviced by the same people who set it.

Ready to see whether your wall can carry the opening you're picturing? Request a quote on this page or call (208) 376-2200.

Last reviewed 2026-09-10 by Wood Windows Inc — (208) 376-2200