| Inswing French doors | Traditional rooms where outdoor space is limited and there is clear interior floor space. | Two hinged panels; common overall widths are about 60–72 in. and heights about 80 in. | Check that the opening is square, plumb, and level. Allow for the swing of both panels and verify the threshold height. | Inspect the meeting astragal, weatherstripping, hinges, and threshold. Keep the swing area clear; clean tracks or thresholds as directed. | Compare NFRC whole-unit U-factor and SHGC for the project’s climate. Check the published air-leakage and water-penetration ratings. |
| Outswing French doors | Homes with limited interior clearance and adequate exterior landing space. | Two hinged panels; often available in similar nominal widths to inswing units, with panel sizes depending on the model. | Confirm that steps, railings, walkways, and screens will not obstruct the outward swing. Check sill support and drainage details. | Check hinge alignment, compression seals, and the center meeting seal. Keep the exterior landing and drainage path clear of debris. | Review the same NFRC energy values, plus air-leakage, water-penetration, and structural-performance information where published. |
| Two-panel sliding patio doors | Everyday access to patios or decks where a swinging door would take up space. | One fixed panel and one sliding panel; common overall widths are about 60–96 in., with heights often near 80 in. | Check the opening width, level sill, header support, and room for the frame. Follow the unit instructions for sill pan and flashing. | Vacuum the track, clear weep openings, and inspect pile weatherstripping and the interlock. Avoid abrasive cleaners on glass and frames. | Compare NFRC U-factor and SHGC, and look for published air-leakage and water-penetration results for the specific configuration. |
| Three-panel sliding patio doors | Wider views and larger openings where a broad glazed area is desired. | Three panels with one or more operating panels; overall widths commonly start around 90 in. and vary by design. | Verify the wider opening, header capacity, floor level, and installation access. Confirm which panels move and where they stack. | Keep the full track clean, check rollers and locks, and inspect the seals between panels. Use adjustment procedures specified for the unit. | Check energy and air-leakage data for the exact panel arrangement; a larger glazed area can affect heat gain and heat loss. |
| Multi-slide patio doors | Large indoor-outdoor openings in renovations or new construction with suitable structural support. | Multiple panels that slide, sometimes into a wall pocket; panel counts and total widths are highly system-specific. | Coordinate the opening, structural header, floor finish, drainage, and any pocket framing before construction. Use the exact installation drawings. | Maintain tracks, drains, rollers, and inter-panel seals. Schedule periodic checks of panel alignment and locking hardware. | Request tested performance for the exact number of panels and configuration, including U-factor, SHGC, air leakage, and water resistance. |
| Folding patio doors | Open-plan spaces where panels can fold to create a broad opening. | Several hinged panels that fold to one or both sides; overall width and panel count vary substantially. | Check structural support, finished-floor height, threshold details, and clear stacking space. Ensure the opening is accurately measured and square. | Clean tracks and hinges, inspect multipoint locks and compression seals, and follow the specified lubrication and adjustment schedule. | Compare ratings for the complete installed configuration, not just a single panel; review energy, air-leakage, and water-test data. |
| Center-hinged patio doors with sidelights | Entry-like patio openings where fixed glass panels add daylight beside an operating door. | One hinged door with one or two fixed sidelights; overall width depends on the selected door and sidelight layout. | Measure the complete frame assembly. Check hinge-side support, sidelight framing, threshold level, and the required rough opening. | Inspect the door perimeter seals, glass seals, threshold, and lock alignment. Clean glazing and check for damaged or loose weatherstripping. | Use the NFRC label for the whole assembly when available. Compare U-factor and SHGC and review published leakage and water ratings. |