For most projects, you should measure from the inside of the building. Interior measurements are more consistent because they’re taken from the structural side of the opening — not from decorative brick, cladding, or stucco that can distort results. Measuring from the inside also allows you to check the subfloor, jambs, and header directly, which are the surfaces that will actually hold the new frame.
However, if your supplier specifically asks for “brick-to-brick” or “exterior reveal” dimensions, take both inside and outside measurements and clearly label them. In European masonry constructions, external brick-to-brick measurements are common, while in North America, most installers rely on inside rough-opening or finished-frame dimensions. When in doubt, record both and note exactly where each was taken — it avoids misunderstandings at the ordering stage.

Every door needs a tolerance gap — a small clearance that allows installers to level, plumb, and insulate the frame properly.
For both entrance and pivot doors, the general rule is to make the door frame 10–15 mm (⅜–⅝ in) smaller than the measured structural opening in both width and height.
This gap ensures there’s enough space for insulation foam and expansion during temperature changes, while still providing a tight, weather-resistant seal.
If the opening isn’t perfectly square, installers can use shims within that tolerance to make micro-adjustments.
Ordering a door that’s the exact same size as the measured opening leaves no room for adjustment and can result in the frame binding or being forced into position — both of which compromise long-term performance.

Uneven floors are a common issue, especially in older houses or spaces that have undergone renovations.
Always check the sill or subfloor with a spirit or laser level.
If one side is higher or lower, measure at multiple points (left, center, right) and base your order on the lowest measurement — installers can always raise the frame slightly using shims, but they can’t make the door shorter once it’s built.
If the variation is more than 5–6 mm, consider having the surface leveled before installation.
For pivot doors, floor levelness is even more critical because the pivot mechanism depends on perfect vertical alignment between the top and bottom pivots.
A sloped or uneven base can cause the door to swing off balance, drag on one side, or damage the pivot bearings over time.

Yes, they do — both in sizing systems and installation methods. In Europe, window measurements are almost always in millimetres (mm) and based on the structural (brick-to-brick) opening. European installers generally leave about 10–15 mm total tolerance for foam and sealing. In North America, measurements are typically in inches and often refer to “nominal” sizes — meaning the advertised 36" × 60" window may actually be slightly smaller to fit a framed rough opening. Also, European windows often open inward (tilt-and-turn or turn-only), while North American ones usually open outward or vertically. When ordering internationally or from metric-based suppliers, always clarify whether dimensions refer to the rough opening size or the actual frame size.

Hinged entrance doors rotate around fixed hinges on one side, so their alignment mainly depends on the frame being plumb and level.
You measure width, height, and diagonals, and ensure the threshold is flat.
Pivot doors, on the other hand, rotate on pivot hardware embedded in the floor and top frame.
Their geometry requires more precision: the pivot axis is offset inward (typically 150–250 mm from the edge), meaning part of the door swings inside and part outside.
If your pivot points aren’t perfectly aligned, the door can tilt or bind.
Additionally, you must confirm that the floor and ceiling structure are strong enough to support the concentrated load at those pivot points — something less critical for traditional hinged doors.

Yes. Pivot doors place significant stress on two concentrated points — the bottom pivot box and the top pivot bearing.
Unlike hinged doors that distribute their weight along the full frame side, pivot doors require solid anchoring in both the floor and header.
The floor should ideally be solid concrete or reinforced wood, and the header should be capable of bearing the top pivot’s load without bending.
Before ordering a large or heavy pivot door (especially over 2400 mm tall), verify with your contractor or KozijnenPro representative that the supporting structure can handle it.
For very tall or wide doors, additional reinforcement plates or concealed steel frames may be recommended to maintain perfect alignment over time.

The pivot offset is the distance from the pivot axis to the door’s vertical edge.
Typical values range from 150 mm to 250 mm, depending on the desired visual balance and passage width.
A smaller offset (closer to the edge) provides a wider usable passage — ideal for narrower openings.
A larger offset creates a dramatic aesthetic effect, as the door seems to “float” and rotate more slowly, but it slightly reduces the clear opening space.
When planning, remember that the pivot offset also affects how much of the door leaf projects inside when open.
If you’re tight on space or have furniture near the door, consider these clearances carefully.
KozijnenPro’s configurator allows you to preview these effects visually before finalizing your design.

Take your tape measure and measure the two diagonals of the opening — from top-left to bottom-right, and top-right to bottom-left.
If the difference between the two measurements is less than 6 mm (¼ in), your opening is acceptably square.
If it’s greater, the frame might not sit flush, leading to visible gaps or uneven operation.
In that case, the opening can either be corrected with minor wall adjustments or compensated for with installation shims.
Checking for squareness is one of the simplest yet most important steps in ensuring long-term door performance.
Even perfectly manufactured doors will perform poorly if installed in a twisted or uneven frame.

Accuracy is everything — especially with aluminium systems, which have tight tolerances. Aim to measure to the nearest millimeter (or 1/16 inch). Avoid rounding up, as it’s safer to have a slightly smaller door with shim space than one that doesn’t fit. Double-check your notes and always label which measurement corresponds to which door. The old saying “measure twice, cut once” applies perfectly here: it’s better to spend extra time verifying your numbers than to face an expensive resizing later.

The top mistakes include:

• Measuring only once, or from decorative trims instead of the actual frame.

• Forgetting to check diagonals and assuming the opening is square.

• Ignoring the impact of new flooring or insulation buildup.

• Confusing width and height entries on order forms.

• Forgetting to label measurements clearly (for example, “rough opening” vs. “finished opening”).

• Not noting the door’s swing direction or pivot side.

• Measuring the old slab or panel instead of the structural opening.
  Avoiding these errors saves time, money, and frustration — and ensures your KozijnenPro door fits perfectly the first time.

Usually not. Unless your supplier requests otherwise, measure from the subfloor to the top of the opening (header) and exclude the existing threshold.
Most aluminium entrance and pivot door systems come with integrated or adjustable thresholds, which are manufactured to match your chosen floor level.
By providing the raw structural measurement, you allow KozijnenPro to determine the correct sill height during production.
If you want a completely flush transition, note your final floor thickness so the new threshold aligns perfectly with the interior surface.