A changed allowance creates a new geometric scenario
When gap or wall clearance changes, recalculate the layout from the new inputs. A count from a zero-spacing plan is not evidence that the same arrangement fits after separation is added. Distinguish clearance deducted at the outer region edges from the gap between neighboring rectangles. The site’s floor model applies the entered clearance on each side of both axes; it does not treat a wall-clearance value as a single total deduction.
Use the actual usable floor dimensions relevant to the assigned equipment and the measured rectangle you intend to place. Carrier examples and presets are scenario references, not promises about a particular unit. The example below uses a hypothetical floor and explicit allowance inputs for checking the engine’s arithmetic. It does not prescribe a general container gap, wall distance or operational clearance requirement.
Rebuild the old eight-pallet uniform plan
Assume a 4900 by 1700 mm region, identical 1200 by 800 mm pallet footprints and no rotation. With zero gap and zero clearance, the uniform count is floor(4900 / 1200) times floor(1700 / 800) = 4 times 2 = 8. Four lengths occupy 4800 mm and two widths occupy 1600 mm. The unused 100 mm in each axis belongs to that particular zero-spacing scenario.
Now enter a 50 mm neighbor gap and 25 mm clearance at each region edge. Usable dimensions become 4900 − 50 = 4850 mm and 1700 − 50 = 1650 mm. Four lengths with three gaps would occupy 4 times 1200 + 3 times 50 = 4950 mm, exceeding usable length by 100 mm. The earlier four-column arrangement is no longer valid, even though its pallet dimensions have not changed.
| Scenario | Usable region and occupied spans | Uniform count |
|---|---|---|
| Gap 0, clearance 0 | 4900 × 1700; four lengths 4800 | 8 |
| Gap 0, clearance 25 | 4850 × 1650; four lengths 4800 | 8 |
| Gap 50, clearance 25 | 4850 × 1650; three lengths 3700, two widths 1650 | 6 |
| Gap 100, clearance 25 | Two widths need 1700, exceeding 1650 | 3 |
| Floor length 5050, gap 50, clearance 25 | Usable length 5000; four lengths need 4950 | 8 for this different floor |
Use the gap formula with the correct number of neighbors
For n equal rectangles on one axis, occupied span is n times item size plus (n − 1) times gap. Solving against the usable span gives floor((usable + gap) / (item + gap)). In the changed example, floor((4850 + 50) / (1200 + 50)) = 3 along length, while floor((1650 + 50) / (800 + 50)) = 2 across width. The resulting uniform pattern contains six pallets.
Do not add a neighbor gap after the last item and call it edge clearance. Conversely, do not use unused end space to erase a required wall deduction. The two allowances have separate meanings in the input model. With a 100 mm gap and the same 25 mm wall clearance, two widths require 1700 mm and fail the 1650 mm usable width. The fixed uniform arrangement therefore has three along length and one across.
Check the revised coordinates as well as the revised count
For the 50 mm gap, 25 mm clearance scenario, a six-case fixed uniform illustration starts columns at x = 25, 1275 and 2525 mm and rows at y = 25 and 875 mm. The final occupied right edge is 2525 + 1200 = 3725 mm, inside the allowed right boundary of 4875 mm. The second row ends at 875 + 800 = 1675 mm, exactly the upper clearance boundary.
The 50 mm differences between neighboring ends and starts confirm the entered separation. A mixed search has its own actual placement list and proof status; use those returned coordinates when reviewing that result. A larger discovered candidate cannot be carried over from another gap scenario. If rotation is allowed, compare that permission consistently, and inspect the oriented dimensions of each rectangle rather than applying the fixed-row formula to a different pattern.
Create an allowance-change review record
Save the original region, item, gap, clearance, rotation permission and result. Record the changed allowance source and the new usable dimensions. For the example retain eight in the original uniform plan and six with 50 mm gap and 25 mm clearance. Attach revised placement information and the new search status. Mark the earlier count as superseded for the changed scenario rather than deleting its input history.
Rerun the tool using the same model boundary
Use the configuration calculator to compare the stated rectangle region and allowances. Use the container floor planner when the task concerns container floor geometry. Confirm how each visible field describes usable dimensions and edge deductions before copying values. The example’s 4900 by 1700 mm region is hypothetical and should not be relabeled as a carrier specification.
The finite identical-rectangle search may return best-found even when a straightforward fixed grid has been checked. Preserve the status, upper bound and any search-limit flag with the candidate. An area upper bound does not automatically incorporate every gap obstruction and is not a promised count. Validating the returned rectangles checks their entered bounds and separation; it does not approve doorway passage or the physical loading sequence.
Inspect what the revised model still omits
A floor plan does not model pallet height, door aperture, payload, local floor support, fork access or restraint design merely because it includes gap and wall clearance. Review those independent interfaces using their actual evidence. If a wrapped pallet measures wider than its empty deck, revise the rectangle dimensions as well as the allowance fields. Reusing a nominal footprint can conceal a different conflict even after the clearance arithmetic is correct.
Reference scope
NIST length guidance supports consistent dimensional units. The entered 25, 50 and 100 mm allowances are explicit example conditions, not published universal handling requirements.