Overhead sectional
- How it operates
- Panels travel up and back on horizontal tracks
- Space it needs
- Interior headroom above the opening and track depth behind it
- Typical use
- Workshops, garages, commercial vehicle access
Selection guide
Doors and Openings
Every hole in a steel building is a structural decision made at order stage, not a fitting installed later. This guide explains what a framed opening is, how the common door types differ in practice, and which decisions must be settled before the building is engineered.
Buyers usually think about doors last, somewhere after size, colour and price. On a pre-engineered building that ordering is backwards: an opening is cut into the wall framing, and the framing around it is designed as part of the building. Choose late and you are changing a design, not adding an accessory.
This page is about that sequence and about the differences between door types that actually change a project. Sizes are a separate subject and we keep them separate — our dimensions reference covers standard door sizes.
Written by Gary Thompson · Steel Building Research EditorSteel Building Research EditorReviewed by Find Steel Buildings Editorial Team
A framed opening is the real product
When a supplier quotes a roll-up door, two different things are being bought. One is the door itself. The other is the framed opening: the additional members around the hole in the wall that carry the load the removed girts used to carry, and that give the door something to fix to.
That distinction explains most of the confusion on quotes. A proposal can include the framed opening and exclude the door, or include both, or include a door with a different opening than you assumed. Ask which, in those words, for every opening on the drawing.
- Framed opening
- The structural provision in the wall. Designed with the building, and expensive to move afterwards.
- Door assembly
- The door, track, hardware and operation. Sometimes supplied by the building manufacturer, often by a specialist.
- Trim and closure
- The weathering detail where the opening meets the panel. Easy to leave out of a comparison.
Openings in a sidewall
- 01Framed opening — the structural framing designed around the hole, part of the building
- 02Jamb — the vertical member at each side of the opening
- 03Header — the member across the top; sized by the building's engineer
- 04Vehicle door — supplied with the building or by a specialist
- 05Walk door — the pedestrian route
- 06Window and louver — also framed openings, on the same schedule
The opening types you will be choosing between
Most steel buildings use a small set of opening types, and the interesting differences are about space and operation rather than appearance.
Overhead sectional doors travel up and back on horizontal tracks, so they need clear space inside above and behind the opening. Roll-up doors coil into a drum above the opening and take less interior depth, which is why they are common on self-storage and compact workshops. Walk doors are the pedestrian route and are almost always worth having in addition to a vehicle door. Windows and louvers are openings too, and they interrupt the girt line the same way a door does.
The order in which these decisions have to happen
The useful mental model is that openings are part of the building's geometry. Before the drawings are sealed, changing an opening is a conversation. After, it is a change order, and after erection it is a structural alteration requiring the engineer of record.
So the practical rule is to think about the whole life of the building at quote stage. Vehicles get bigger. A workshop becomes a shop front. A future extension needs a doorway on the gable end. It is far cheaper to frame an opening now and fit the door later than to cut one afterwards.
Door and opening types compared
Operation and space consequences, not sizes. Dimensions are covered in the dimensions reference.
Roll-up
- How it operates
- Curtain coils onto a drum above the opening
- Space it needs
- Headroom for the drum; little interior depth
- Typical use
- Self-storage, agricultural, compact shops
Sliding
- How it operates
- Leaf slides sideways across the wall face
- Space it needs
- Clear wall length beside the opening
- Typical use
- Agricultural and equipment buildings
Walk door
- How it operates
- Hinged pedestrian door
- Space it needs
- Swing clearance only
- Typical use
- Every building that people enter on foot
Window
- How it operates
- Fixed or opening glazed unit
- Space it needs
- Framed opening in the girt line
- Typical use
- Offices, shop areas, daylight at eye level
Louver
- How it operates
- Fixed weatherproof air opening
- Space it needs
- Framed opening plus interior clearance
- Typical use
- Ventilation air paths
Operation descriptions are general. What your building can accommodate depends on its engineered design.
Ask this for every opening on the drawing
Is the framed opening included?
- Why it changes the quote
- The structural provision and the door are separate scopes and are often split.
Who supplies and installs the door?
- Why it changes the quote
- Vehicle doors are frequently a specialist scope outside the building package.
Is the door manual or powered?
- Why it changes the quote
- Powered operation adds an electrical scope nobody in the building quote owns.
What trim and closures come with it?
- Why it changes the quote
- The weathering detail around an opening is a common omission.
Can this opening move later?
- Why it changes the quote
- It tells you whether you are making a preference or a permanent decision.
What sits outside the building supplier's scope
Doors bring in trades. Operators need power, which is an electrical scope. Approach slabs, aprons and thresholds are site work. Fire-rated assemblies, accessibility requirements and egress provisions are governed by the code applying to your building and its use, and they are confirmed with your design professional and the authority having jurisdiction rather than assumed from a catalogue.
None of that is a reason to worry. It is a reason to ask, per opening, who supplies it, who installs it, and who is responsible for the interface.
What belongs to the building's engineer
Headers, jambs, reinforcement around openings and the loads a door assembly must resist are engineered for your building. Nothing on this page sizes an opening, specifies a header or states what any door assembly is capable of resisting.
Settle these before the building is engineered
- 01Opening schedule. Every opening listed on the drawing with its location, before the design is sealed.
- 02Framed opening vs door. Which of the two each line item covers.
- 03Clear opening. The usable dimension after framing and hardware, not just the nominal size.
- 04Power. Whether any door is powered and who provides the supply.
- 05Future openings. Whether to frame now for a door fitted later.
- 06Approach and thresholds. Who is responsible for the slab, apron and threshold at each vehicle opening.
Terms used on this page
- Framed opening
- The structural framing around a hole in the wall, designed with the building.
- Jamb
- The vertical member at the side of an opening.
- Header
- The member across the top of an opening. Sized by the building's engineer.
- Clear opening
- The usable width and height once framing and door hardware are in place — not the same as the nominal size.
- Walk door
- A pedestrian door, as distinct from a vehicle door.
Frequently asked questions
That depends on what has to pass through it and what the building is for, and it is a dimensions question rather than a component question. Our reference guide to standard garage door sizes sets out the common sizes and how to think about clearance. What this page adds is the reminder that the opening has to be framed for that size before the building is engineered.
Sometimes, but it is a structural alteration rather than a fitting job, because the wall framing at that location was designed without the opening. It has to be assessed by a qualified engineer for the specific building. Framing an opening at order stage and hanging the door later is nearly always the cheaper route.
Often not, or only partly. Building packages commonly include the framed opening and sometimes a basic walk door, while vehicle doors and operators come from a specialist. This is why comparing two building quotes on price alone is unreliable until you have asked, per opening, exactly what is in the box.
How they store when open. A roll-up curtain coils onto a drum above the opening, needing headroom but little interior depth. A sectional door travels up and back along horizontal tracks, needing depth inside the building above the ceiling line. The choice usually follows how much interior space you can afford to give up.
Yes. Anything that interrupts the girt line needs framing designed with the building, which is why windows and louvers appear on the same opening schedule as doors. Louvers also form part of the ventilation strategy, so their positions are worth settling alongside the ventilation decisions.
Verification and sources
Every material statement on this page maps to a published source, and each record states what that source does not cover. Where something was not verified it is recorded as not verified rather than estimated.
Openings are part of the engineered system · Tier 1
Framing around openings in a metal building system is part of the engineered structure rather than a field-added accessory.
Establishes that openings are engineered. No member, header or reinforcement is specified here.
Metal Building Manufacturers AssociationDoor types and operation · Tier 2
Sectional, rolling and other commercial door types are published as distinct product categories with different operating mechanisms by the door industry's trade association.
Supports the category descriptions only. No product, size or performance claim is made.
International Door AssociationCode and accessibility boundary · Tier 1
Egress, fire and accessibility requirements for doors are set by the building code adopted in the project's jurisdiction.
Points to where the requirements live. No requirement is stated, interpreted or applied to any building.
International Code CouncilNot verified · Tier 4
No opening size, header size, clearance figure or wind-load value is published on this page.
Records a deliberate absence. Sizes are covered in the dimensions reference; structural provision belongs to the engineer of record.
Find Steel Buildings editorial policyWhere to go next
Next step
Standard garage door sizes
Dimension intent belongs to the reference silo, and this is where buyers go next.
Also useful
Compare building quotes
Openings must be on the specification before quotes are comparable.
Planning a building?
Compare steel building quotes
Openings are the easiest thing to leave vague and the most expensive to change. Fix the opening schedule before you ask suppliers to price the building.
Requests go to Find Steel Buildings so we can compare whole-building options. Find Steel Buildings does not sell individual components, no component manufacturer or named company receives your request, and we are not affiliated with the companies referenced on this page.