Common Window Types Reference
Why this matters
Service techs encounter windows constantly: caulking, painting, replacing sash, troubleshooting drafts, glass repair. The tech who recognizes window types + their parts diagnoses + sells correctly. This is the field card.
Window operating types
Single-hung: bottom sash slides up; top fixed. Most common older + builder-grade.
Double-hung: both sashes slide independently. Easier cleaning; better ventilation.
Casement: hinged at side; crank-operated; opens out. Best airtight seal.
Awning: hinged at top; opens out; rain-resistant.
Hopper: hinged at bottom; opens in. Often basement.
Sliding (glider): horizontal slide; common patio doors + side panel.
Fixed (picture window): doesn't open; maximum view.
Bay: 3-panel projection; center fixed + side angles.
Bow: 4-5 panel curved projection.
Garden: small projection; like a bay; plant-display.
Skylight: in roof; fixed OR vented.
Solar tube: small tube; brings light to interior; doesn't open.
Egress: required size for bedroom; per IRC.
Window frame materials
Vinyl: most common new construction; affordable; low maintenance; expansion/contraction.
Wood: traditional; high-end; high maintenance.
Aluminum: lightweight; conducts heat (poor insulator); common commercial.
Aluminum-clad wood: wood interior + aluminum exterior; best of both.
Fiberglass: low expansion; durable; less common but premium.
Composite: wood + plastic; low maintenance.
Steel (commercial): durable; specialty.
Glazing (covered in glass + glazing types)
Single-pane: drafty; older homes.
Double-pane (insulated glass unit): standard since 1990s.
Triple-pane: cold climates; better R-value.
Argon OR krypton gas fill: noble gases between panes; improves insulation.
Low-E coating: low-emissivity metallic film; reflects heat.
Tempered: safety locations (doors, near floor, etc.).
Laminated: hurricane impact, sound, UV.
Window parts
Frame (outer perimeter); sash (movable; holds glass); meeting rail (where sashes meet on double-hung); mullion (vertical bar between units); muntin (divides glass within sash; or GBG "grilles between glass"); sill (bottom interior + exterior); stool (interior horizontal); apron (trim below stool); casing (interior trim); brickmould (exterior trim); drip cap (above exterior); weatherstripping (seals sash); sash lock (meeting rail); balance (spring/spiral; holds sash); tilt latch (sash tilts in for cleaning).
Common window problems
Drafty: weatherstripping degraded; sash gap; failed sealant.
Hard to operate: paint buildup; broken balance; debris in tracks.
Foggy between panes: IGU seal failed; gas escaped; condensation between panes.
Cracked / broken glass: replace glass (tempered if code-required).
Stuck closed (painted shut): utility knife along sash + frame to break seal.
Stuck open: broken balance; sash falls when released.
Water leak: failed exterior caulk OR flashing; window flashing repair.
Air leak: weatherstrip OR caulk replacement.
Damaged sash: replace OR repair.
Window seal failure (IGU)
Symptoms: fog OR moisture between panes; visible drip pattern.
Causes: aged seal (15 - 25 yr typical lifespan); UV damage; thermal cycling.
Repair: replace IGU (sash often reusable).
Don't repair sealant alone: gas already gone.
Window flashing
Required around windows to prevent water entry.
Components: pan flashing under sill, side flashing, head flashing, drip cap.
Materials: self-adhesive flashing tape (Grace Vycor, 3M All-Weather), aluminum, copper.
Sequence: bottom first, sides, top last (water flows down).
Common failure: water entry behind siding from missing OR improperly-installed flashing.
Storm windows + storm doors
Aluminum storm window: secondary glazing outside primary window; energy improvement.
Interior storm: removable inside.
Combination storm-screen: switchable.
Common in: homes with original single-pane windows.
Window energy efficiency
U-factor: 1/R-value; lower = better insulation.
SHGC (Solar Heat Gain Coefficient): lower = blocks more solar heat.
ENERGY STAR: certified by climate zone.
Typical residential:
- North: U 0.25 - 0.30, SHGC 0.30 - 0.40
- Central: U 0.30 - 0.35
- South: U 0.40 - 0.50, SHGC 0.25 - 0.30
Tax credit OR rebate: federal + utility incentives.
Window install procedure (new construction OR replacement)
- Measure opening (height + width; check square + level + plumb)
- Order matching window
- Prepare opening (remove old, repair framing if needed)
- Install pan flashing in bottom of opening
- Set window in opening; level + plumb
- Shim as needed; secure with fasteners through frame
- Install side + head flashing
- Caulk exterior gap
- Insulate gap between window + framing (low-expansion foam OR fiberglass)
- Install interior trim + casing
- Caulk + paint
Caulking around windows
Exterior: polyurethane sealant (Sika, Bostik); 25-year flexibility.
Interior: latex acrylic; paintable; less flex needed.
Don't caulk weep holes: water needs to drain out.
Reseal every 5 - 10 years: typical lifespan.
Sash rope / chain / balance repair
Older single + double-hung wood windows: sash rope + counterweight system; chain replacement common service.
Modern vinyl + fiberglass: spiral OR block + tackle balance.
Diagnosis: window won't stay up; loose or stretched.
Replacement: per OEM; balance kits available.
Common service-call scenarios
"Window won't close completely": weatherstrip + track inspect; lubricate; replace if degraded.
"Window seal failed (foggy)": order new IGU; replace.
"Painting window casement": prep + caulk + paint; mask glass.
"Replace broken pane": cut new glass; install; glaze + putty.
"Drafty windows": caulk exterior; weatherstrip interior; storm window addition.
Customer education
Energy savings: 10 - 30% on heating + cooling.
Sound reduction: laminated OR triple-pane.
UV protection: low-E coating blocks 99% UV.
ENERGY STAR: rebates + tax credits.
Lifetime warranty: most major brands offer 20+ yr.
ROI: 10 - 15 yr typical to recoup investment in energy savings alone.
Truck stock for window service
Caulk (polyurethane exterior + latex interior; caulking gun), self-adhesive flashing tape, weatherstrip foam, glazing compound + glazing points, putty knife, utility knife, work gloves + safety glasses, IGU measuring tool.
Common code requirements
Egress (bedroom): per IRC R310; 5.7 sq ft net opening (5 sq ft for grade floor); 24" min height; 20" min width.
References
- IRC R308 (glazing), R310 (egress), R703 (water-resistive barrier)
- ENERGY STAR window standards
- AAMA standards (window performance)
- NFRC (National Fenestration Rating Council)
- Manufacturer technical data (Andersen, Pella, Marvin, Milgard, Jeld-Wen)
- Manuall internal: Glass + Glazing Types, Flashing + Weatherproofing