What Size Housing Does a Motorized Screen Need?
A motorized screen needs a housing of about 3 to 4 in (76 to 100 mm) for an opening up to about 10 ft (3 m) wide and 8 ft (2.4 m) tall, about 5 in (127 mm) for openings up to 16 to 20 ft (4.9 to 6.1 m) wide, and 6 in (152 mm) or more beyond that, up to about 26 ft (7.9 m), or 39 ft (12 m) with support cradles. Those breakpoints come from the published limits of six makers, gathered below in one table. The size is set by the opening, not the brand: a wider screen needs a thicker roller tube, a taller drop needs a fatter roll of fabric, and the box has to hold both. Privacy fabric and clear vinyl push you up a size, because several makers only offer them in their larger boxes.
Key takeaways
- Compact boxes stop early: Stoett's 3 in housing at 120 in (10 ft) wide motorized, Draper's 3-5/8 in (92 mm) headbox at 11 x 11 ft (3.35 x 3.35 m).
- The 4 in (100 mm) class reaches about 10 to 13 ft wide; the 5 in class 16 to 20 ft; the 6 in and larger class 24 to 26 ft, and 12 m (39.4 ft) with support cradles.
- Privacy fabric and clear vinyl are often limited to the larger boxes.
- Check what the number measures. Draper quotes its ZIP headboxes by height only; a square 105 x 105 mm box needs a different pocket from a deeper one.
Why one dealer says 3 inches and another says 6
Both are quoting real products. Housings come in steps, and each step has a ceiling. Compact-screen brochures lead with the small box ("a compact 3 in protective housing", in Stoett's words); guides to porch screens quote the 5 to 6 in (127 to 152 mm) those openings need, as we do in motorized patio screens. The small number is right only for small openings. For a typical 12 to 16 ft porch bay, plan on the larger one.
Housing size against maximum opening, by maker
Sources: Stoett's PanoramaLite flyer and Panorama flyer; Draper's Exterior Motorized FlexShade and FlexShade ZIP pages and its FlexShade XL announcement; KE Outdoor Design's exterior screen specification sheet; the Phantom Executive Motorised specification from Phantom Screens NZ; the Renson Fixscreen 100 page; and usine-online's ZIP 85 and 105 listing.
| Housing | Product | Max width | Max drop | Stated condition |
|---|---|---|---|---|
| 3 in (76 mm) | Stoett PanoramaLite | 120 in (10 ft; 3.05 m) motorized; 174 in (14.5 ft) spring assisted | 108 in (9 ft; 2.74 m) | Motorized minimum width 24 in |
| 3-5/8 x 3-5/8 in (92 x 92 mm), square or curved | Draper Exterior Motorized FlexShade | 11 ft (3.35 m) | 11 ft (3.35 m) | "Depending on fabric selection"; side channels or cables hold the hem bar, not the fabric edge |
| 85 mm (3.3 in) | usine-online ZIP 85 | 6 m (19.7 ft) | 2.3 m (7.5 ft) | Low drop only |
| 100 x 100 mm (3.9 in) | Renson Fixscreen 100 | Not stated for the base model | Not stated | EN 13561 wind class 3 |
| 100 mm (3.9 in) | Phantom Executive (Phantom Screens NZ) | 3.0 m (9.8 ft) | 2.45 m (8.0 ft) | Compatible insect and solar meshes only |
| 4 in (102 mm) | KE CS4 cassette | 13 ft (3.96 m) | 10 ft (3.05 m) | 70 mm roller tube; clear vinyl to 8 ft drop |
| 105 x 105 mm (4.1 in) | usine-online ZIP 105 | 7 m (23 ft) | 4 m (13.1 ft) | Up to 18 m² (194 sq ft) in total; wind class 6 or 5 by size |
| 92 mm or 127 mm tall (3-5/8 or 5 in) | Draper FlexShade ZIP 92 / ZIP 127 | 16 ft (4.88 m) | 15 ft (4.57 m) | Range limit for the product; the page does not split it by headbox |
| 5 in (127 mm) | Draper Exterior Motorized FlexShade XL | 16 ft (4.88 m) | 11 ft (3.35 m) | Integrated cradle support in the headbox |
| 5 in (127 mm) | KE CS5 cassette | 20 ft (6.10 m) | 16 ft (4.88 m) | 80 mm tube to 16 ft wide, 85 mm to 20 ft |
| 6 in (152 mm) | Stoett Panorama | 288 in (24 ft; 7.32 m) | 156 in (13 ft; 3.96 m) | Maximum for standard and no-see-um mesh only |
| 6 in (152 mm) | KE CS6 cassette | 26 ft (7.92 m) | 16 ft (4.88 m) | Minimum width 6 ft; 110 mm tube |
| 140 or 180 mm (5.5 or 7.1 in) | Phantom Executive (Phantom Screens NZ) | 8 m (26.2 ft); to 12 m (39.4 ft) with support cradles | 5 m (16.4 ft); 3.3 m (10.8 ft) above 8 m wide | Housing and roller "selected for the configuration" |
Read down the max width column and the steps are clear. Among motorized boxes under 100 mm, only the ZIP 85 passes 11 ft wide, and it does so with a drop that stops at 2.3 m, so the roll stays thin. Among the 100 to 105 mm boxes, only the ZIP 105 passes 13 ft, and its 18 m² cap means a wide screen in it has to be short. Every box rated past 20 ft at a full 13 to 16 ft drop is 140 mm (5.5 in) or larger.
What sets the size: the tube for width, the roll for drop
A housing has to enclose the roller tube plus every turn of fabric wound on it.
Width sets the tube. A longer tube sags more in the middle, and a sagging tube winds the fabric unevenly. KE's sheet shows the steps: a 70 mm tube up to 13 ft wide, 80 mm to 16 ft, 85 mm to 20 ft and 110 mm to 26 ft. It lists the 4 in cassette with the 70 mm tube, the 5 in with the 80 and 85 mm tubes and the 6 in with the 110 mm tube, so the cassette width limits (13, 20 and 26 ft) line up with the tube limits.
Drop sets the roll. Every turn adds two fabric thicknesses to the diameter, so a taller drop or a thicker fabric makes a fatter roll on the same tube. How the roll is driven and supported is explained in how retractable screens retract.
Fabric and vinyl can force the larger box
The table's limits are for the fabrics each maker names, and the heavier or stiffer options are often restricted to the big housings:
- Privacy fabric. Phantom Screens NZ offers its Visiontex and other polyester privacy fabrics only in the 140 and 180 mm housings, to 8 m wide by 3.9 m (12.8 ft), and not on oversized spans above 8 m. The 100 mm box takes only "compatible insect and solar meshes".
- Clear vinyl. Phantom Screens NZ lists clear PVC for the 140 and 180 mm housings only. KE allows clear vinyl windows in all three cassettes, but at lower limits: 13 ft by 8 ft in the CS4, 16 ft by 12 ft in the CS5 and 16 ft by 8 ft in the CS6.
- Solar mesh. Stoett's 288 x 156 in Panorama limit is marked "for standard and noseeum mesh only", so its 80 and 90 percent solar meshes are not covered by the headline figure.
So decide the fabric before the box. Mesh weights and openness are compared in screen mesh openness factor.
Which housing size to plan for
Take the smallest measured width and the longest drop (the method is in how to measure for retractable screens) and read across. The breakpoints are the published limits above.
| Opening width | Drop up to 8 ft (2.4 m) | Drop 8 to 11 ft (2.4 to 3.35 m) | Drop 11 to 16 ft (3.35 to 4.9 m) |
|---|---|---|---|
| Up to 10 ft (3 m) | 3 to 4 in (76 to 100 mm) | 3 to 4 in, if the maker's chart allows the drop (Stoett 3 in to 9 ft, Draper 92 mm to 11 ft, KE 4 in to 10 ft) | 5 in (127 mm) |
| 10 to 13 ft (3 to 4 m) | 4 in (KE CS4) or 105 mm | 4 in to 10 ft drop; otherwise 5 in | 5 in |
| 13 to 16 ft (4 to 4.9 m) | 5 in | 5 in (Draper XL, KE CS5) | 5 in (KE CS5 to 16 ft drop) |
| 16 to 20 ft (4.9 to 6.1 m) | 5 in (KE CS5), or 5.5 in (140 mm) | 5 to 5.5 in | 5 to 5.5 in |
| 20 to 26 ft (6.1 to 7.9 m) | 6 in or larger (Stoett Panorama to 24 ft and 13 ft drop; KE CS6 to 26 ft and 16 ft drop; Phantom NZ 140 or 180 mm to 8 m and 5 m drop) | ||
| Over 26 ft (7.9 m) | 180 mm class with support cradles (Phantom NZ to 12 m at a 3.3 m drop), or two screens with a post between them | ||
Surface mount or recessed: what the number means for the build
On a surface mount the box sits under the beam or on the wall face, and the full box height comes off the clear opening unless it is mounted above. On a garage that matters for vehicle height, as covered in garage door screens. A recessed box goes into a ceiling or beam pocket and must be planned before the ceiling is closed, which is the point we make in porch and lanai screen enclosures.
For a pocket, get the maker's section drawing for the exact box, not the headline size, and ask for the depth where only a height is quoted. The tracks need their own allowance on the posts: Draper's ZIP side channels are 1-5/8 in (41 mm) wide, usine-online's 42 mm wide by 55 mm deep. Track profiles are compared in screen tracks and guide rails, and the fixing sequence for the box and tracks is in installing motorized patio screens.
Where these numbers stop applying
A bigger box is not a higher wind rating. Housing size is about fitting the roll, not about wind. Renson's 100 mm Fixscreen is rated EN 13561 class 3, and usine-online rates its 105 mm box class 6 or 5 depending on size. Wind resistance comes from the edge retention and the opening size; see zip track screens and wind.
They are maxima for the products named. Makers cap size by fabric and by width-to-height ratio, and product lines change, so confirm the box for your exact order before framing. Price ranges are in retractable screen cost.
Frequently asked questions
Can a 4 inch housing hold a 16 foot screen?
Not in any maker sheet we read at a normal door-height drop. KE's 4 in cassette stops at 13 ft and Phantom NZ's 100 mm housing at 3.0 m (9.8 ft). The only box near 4 in that goes wider is usine-online's 105 mm box, to 7 m, but it is capped at 18 m² (194 sq ft) in total, so a 16 ft wide screen in it is limited to about 12 ft of drop.
Do 85, 100 and 125 in a screen's model name mean millimeters?
Often, but check. usine-online's ZIP 105 has a 105 x 105 mm box and Renson's Fixscreen 100 a 100 x 100 mm cassette. Draper's ZIP 92 and ZIP 127 are named for the headbox height in millimeters. A model number on its own is not a drawing, so get the dimensions in writing before you frame a pocket.
Sources and standards consulted
- EN 13561:2015, External blinds and awnings (covers vertical external screens and wind classes) (CEN)
- Screen mesh specification sheets (fiberglass, polyester and PVC-coated meshes) (manufacturer documentation)
- Energy Efficient Window Attachments (U.S. Department of Energy, Energy Saver)
- Attachments Energy Rating Council (AERC) rating program (AERC)
See how we research for our sourcing and verification process.