Tilt and Turn vs Casement Windows

A tilt and turn window swings inward on side hinges and also tilts inward from the top, all from one handle; a casement, in its common US form, swings outward on side hinges with a crank. Both are hinged-sash windows that press the sash against a gasket when closed. Natural Resources Canada lists them as separate operable types alongside awning, hopper and slider windows. The choice comes down to swing direction, screens, clearance and how the window is used day to day. For the full mechanism, see tilt and turn windows.

Side-by-side comparison

Operation

A casement sash is hinged on one vertical edge. The crank pushes the sash out on an arm; most US units are built this way. A tilt and turn sash has a hinge point on the bottom and one on the side, and the handle decides which one is active. Tilt and turn therefore has a mode that a casement does not: a small controlled opening at the top, with the sash held at the bottom pivots and limited by a stay arm.

The mechanism also differs in how the sash is held shut. A tilt and turn window locks at several points around the perimeter through a drive rod, while a casement typically uses a handle that moves a limited number of latch points, depending on the product. Counts and arrangements vary by maker, so ask the supplier for the lock-point layout rather than assuming.

Sealing, rain and wind

Both types seal with gaskets that compress when the sash is closed, and both are rated through the same North American standard as any other window. That standard, AAMA/WDMA/CSA 101/I.S.2/A440, certifies air leakage, wind pressure and water penetration resistance. FEMA explains that the PG rating shows the lowest outcome of the applicable tests and that a PG 60 product has passed the water test at 9 psf, which is 15 percent of its 60 psf design pressure.

What matters for the comparison:

• Compare the PG rating and the test report of the actual unit, not the category.
• An inward-opening sash closes toward the frame from the inside, so the exterior side carries the weather detail. Inward-opening windows explains sill and drainage considerations.
• An outswing casement puts the hinges, operator and open sash outside the building, so they face the weather when open.

Screens

Casement screens are normally mounted on the room side because the sash swings outward. A tilt and turn sash swings into the room, so the screen cannot sit in that space. Screens go on the exterior, and one US screen maker states that its fixed exterior screen works only when the sash is offset from the frame, not with flush sash and frame designs. If screens are required on every operable window, check this at the frame-profile stage.

Clearance and use

• Tilt and turn: needs open floor and wall space inside. Curtains, blinds, radiators and deep sills must clear the swing arc.
• Casement: needs open space outside. A balcony, walkway, porch rail or shrub within the swing arc can block or be struck by the sash. A wide outswing sash catches wind when open.
• Cleaning: in turn mode, the outside of a tilt and turn window can be reached from inside. An outswing casement usually needs outside access unless it has a special cleaning hinge.

Hardware weight and size

The hinge carries the sash weight in both types. Published ratings show how large the numbers get for tilt and turn: one heavy-duty line is rated for sash weights up to 440 lb (200 kg) in tilt and turn mode and up to 660 lb (300 kg) in turn-only mode, with a tilt depth capped at 80 mm (about 3 in). Casement operators and friction hinges are rated differently, and wide, tall casements are usually limited by the operator and by wind loading rather than by the sash weight alone. In both cases, ask for the maximum sash weight and size of the hardware set and compare it with the glazing weight.

Egress

Operable windows can serve as emergency escape and rescue openings. Under the 2021 IRC, the opening needs at least 5.7 sq ft net clear area (5 sq ft at grade floor), 24 in clear height and 20 in clear width, with the bottom of the clear opening at most 44 in above the floor (R310.2.1 to R310.2.3), and it must be operable from inside without keys, tools or special knowledge (R310.1.1). The dimensions are measured as the result of normal operation.

• A tilt and turn window qualifies in the turn position only. Tilt never counts.
• A casement qualifies when the sash opens wide enough that the hinge-side sash and hardware do not reduce the clear opening below the minimums.

Both are subject to local amendments; confirm with the building official. See egress window requirements.

Which to choose

• Choose tilt and turn when inward opening is wanted: upper floors, tight exteriors, cleaning from inside, two ventilation modes, a European-style sash.
• Choose casement when interior space around the window is tight, when occupants expect a crank, or when exterior clearance is not a problem and room-side screens are required.
• Neither type changes the thermal performance by itself. U-factor and SHGC come from the glazing, frame, spacer and size, and are read from the NFRC label on rated products.

For how these conventions differ from mainstream American windows, see European vs American windows.