In short
- A shop door size calculator starts with your tallest vehicle (roof air conditioner and antennas included), adds a margin, and rounds up to the next whole-foot door.
- Many builder guides point to a 14 ft door for a Class A motorhome and suggest at least 1.5 ft over the roofline in some cases. Rigs with rooftop gear can need more.
- The door is not the wall: a roll-up needs about 12 to 18 in above the opening and a sectional about 10 to 24 in, so the wall at the door is taller than the door.
- A 12.5 ft rig with a 1 ft margin needs a 14 ft door and about 15 to 15.5 ft of wall behind it.
On this page
This shop door size calculator is for Tyler and Smith County owners planning a barndominium shop who want to know what door and wall height to ask the builder for. Enter the tallest and widest thing you will park inside, pick the door type and a margin, and it gives the door size and the wall height behind it. It supports our shop planning guide.
En español: calculadora de tamaño de puerta para el taller
| Your numbers |
|---|
Example: roll-up, 12.5 ft tall by 8.5 ft wide, 1 ft margin, 4 ft extra width.
How the numbers are worked out
- Opening needed.
Tallest height plus your margin: 12.5 + 1 = 13.5 ft.
- Door height.
Round up to the next whole foot, since doors are quoted in standard sizes: 14 ft.
- Door width.
Widest part plus your extra width, rounded up: 8.5 + 4 = 12.5, so 13 ft.
- Wall at the door.
Door height plus the headroom the door type needs. A roll-up needs 12 to 18 in: 14 + 1.0 = 15.0 ft up to 14 + 1.5 = 15.5 ft.
- Range.
The range runs from the low to the high headroom for the door type. If you enter the supplier number, it shows one value.
Rig height against door and wall
| Rig height | Door height | Roll-up wall |
|---|---|---|
| 12.0 ft | 13 ft | 14.0 - 14.5 ft |
| 12.5 ft | 14 ft | 15.0 - 15.5 ft |
| 13.5 ft | 15 ft | 16.0 - 16.5 ft |
| 14.5 ft | 16 ft | 17.0 - 17.5 ft |
These use a 1 ft margin and the typical roll-up headroom of 12 to 18 in. Heights are examples from builder guides and RV storage guides: Class A motorhomes are often 12 to 13.5 ft, and rooftop gear can push real clearance higher. Measure your own rig.
Door types and headroom
| Door type | Headroom | Note |
|---|---|---|
| Roll-up | 12 to 18 in | Often fits a steel endwall; usually less insulated |
| Sectional | 10 to 24 in | Insulates better; more track and motor space |
Headroom ranges are from builder blogs and vary by model. The door maker's published number for the exact door controls.
Planning numbers, not a door order. The door maker sets the real opening and headroom, and your builder or engineer sets the header and eave height. Wind rating and framed openings matter as much as size: see our windows and doors bid guide.
Where a shop door goes wrong
- Measuring the brochure height. Listed height often leaves out the roof air conditioner, antennas and vents. Measure the real highest point.
- Forgetting the wall. A 14 ft door in a 14 ft wall does not work. Ask for the clear height at the door, not the eave on the plan.
- Planning for today's rig only. The door is cheapest to frame during the build. Think about the next rig, not just the current one.
- Slab and drive in front. A tall rig needs a level approach and a turn-in. Check the slab and drive plan with the door.
What to ask your builder
- What is the door height and the clear height behind it? Ask for both on the plans.
- Which door type and what headroom? Ask for the door maker's published headroom number.
- What is the header and how is it braced? A wide opening carries more load. Ask who designs it.
- What wind rating does the door carry? See the bid guide and the builder guide.
Next step: get a written quote
This tool sizes a door, not the building or the price. We are a referral service, not a contractor; we connect visitors with independent local providers. Use the form below to ask independent barndominium builders near Tyler for a written quote that lists the shop door height, width and wall height, and read how to choose a barndominium builder first.
Sources
- Garage Door Sizes for Class A, B & C Motorhomes, Pro-Built Steel: door height by motorhome class.
- RV Garage Door Sizes, Precision Door: RV door heights and clearance.
- How Tall Is an RV?, RecNation Storage: typical RV heights by class.
- Federal Size Regulations for Commercial Motor Vehicles, FHWA: no federal height limit; states set 13 ft 6 in to 14 ft.
Frequently asked questions
What size garage door do I need for an RV in a barndominium?
Measure the highest point of the rig with its roof air conditioner and antennas, add a margin, and round up to the next door height. Many builder guides point to a 14 ft door for Class A motorhomes, and some suggest 16 ft for a taller rig or one you may buy later. The door maker confirms the real opening size.
Is the door height the same as the wall height?
No. The door hardware sits above the opening. A roll-up coils above the door and sectional tracks need headroom too, so the wall or header at the door must be taller than the door. Published headroom figures run from about 10 to 24 inches depending on door type and model; the door maker's number for the exact door controls.
How wide should a shop door be?
Enter the widest part of what you park, including mirrors and any slide-out or loader bucket, and add room to steer in. This calculator adds a total of 2, 4 or 6 ft that you choose; there is no code rule for it, so pick based on how easy you want the turn-in to be.
Can I make the door taller after the building is up?
It usually costs much more than framing for it up front, because the header and wall panels change. Settle the tallest door you might want before the steel package is ordered, and ask your builder what a taller opening would change.