Leasing plan efficiencies — aperiodic tiles vs. modular grids

@@ -0,0 +1,78 @@
---
schema: foundry-doc-v1
title: "Leasing plan efficiencies — aperiodic tiles vs. modular grids"
slug: bim-leasing-plan-efficiencies
short_description: "Quantitative case for the aperiodic tile system: irregular Private Office widths produce 1.78 times more distinct leasable configurations than a uniform modular grid at 95 percent of the area, with 78 percent of the door and service hookup count."
category: building-design
type: topic
content_type: topic
quality: complete
status: pre-build
audience: operator
bcsc_class: vendor-internal
language_protocol: PROSE-TOPIC
last_edited: 2026-05-17
editor: pointsav-engineering
paired_with: building-design/bim-leasing-plan-efficiencies.es.md
---

The [[bim-floor-plate-methodology|Floor Plate Methodology]] defends a specific design claim: an aperiodic [[bim-tile-system|tile system]] with irregular [[bim-key-plans-index|Key Plan]] widths produces more distinct leasable configurations per square foot than a uniform modular grid. This topic isolates the quantitative argument and the secondary leasing levers — climate-zone autonomy, demising tolerance, and rolling efficiency. Named assembly examples appear in [[bim-floor-plate-tile-combinations|floor-plate tile combinations]].

## The 16-vs-9 result

A row of nine uniform 325 SF cells yields nine distinct contiguous leasehold sizes: 325, 650, 975, 1,300, 1,625, 1,950, 2,275, 2,600, and 2,925 SF. Total area: 2,925 SF. Combinations: 9. Climate zones: 1. Doors: 9. Service hookups: 9.

The same row length filled with irregular [[bim-private-office-key-plans|Private Office]] widths (325 + 465 + 325 + 685 + 325 + 325 + 325 = 2,775 SF) yields **sixteen** distinct contiguous leasehold sizes ranging from 325 SF to 2,775 SF. Climate zones: 1. Doors: 7. Service hookups: 7.

The aperiodic system delivers 1.78× more distinct leasable configurations at 95% of the area with 78% of the door and hookup count. The leasing instrument can match a wider distribution of tenant-requested footprints without recomposing the Tile.

## Professional Office sub-type combination counts

The same argument extends across [[bim-professional-office-key-plans|Professional Office]] sub-types:

| Sub-type | Aperiodic combinations | Modular combinations | Total SF |
|---|---:|---:|---:|
| Laboratory | 30 | 18 | 5,550 |
| Medical | 30 | 18 | 5,550 |
| Civic | 42 | 27 | 8,325 |
| Academic | 30 | 18 | 5,550 |

The Civic sub-type achieves the highest combination count because the larger plate area (8,325 SF) admits more intermediate demising-wall positions while preserving the irregular-width nesting property.

## Climate-zone autonomy as a leasing instrument

Every Tile is exactly one HVAC climate zone. A tenant who wants full thermostat control must lease a whole Tile; a tenant who leases part of a Tile shares the climate zone with adjacent tenants. The leasing agreement makes the trade-off explicit and prices it accordingly.

| Tenant footprint | Tile position | Climate zones shared |
|---|---|---|
| 300 SF Private Office | Tile segment | 4 other tenants |
| 2,700 SF Corporate | Whole Tile A | None — full climate authority |
| 4,900 SF Corporate | Whole Tile F | None — full climate authority |

## Demising tolerance

The methodology permits demising walls to fall on any Tile edge. The cost of crossing a Tile boundary is loss of climate-zone control: the two tenants sharing a partial Tile share the HVAC zone. The HVAC system cannot be split mid-tile without rebuilding the duct routing.

The leasing instrument disincentivises mid-tile demising through a premium rent line item but does not prohibit it. No engineering workaround for a mid-tile demising wall exists short of full HVAC re-engineering — a conclusion documented in the V12 Methodology Solutions section.

## Rolling efficiency

The methodology rejects the traditional efficiency metric (net leasable / gross buildable) in favour of Rolling Efficiency: the share of the floor that is actively leased and represented by a Key Plan matching a real tenant's furniture inventory.

A floor at 88% engineering efficiency with seven tenants in mixed Tile compositions, each at full utilisation within their leasehold, outperforms a floor at 100% engineering efficiency occupied by one tenant whose furniture does not fit the space. The catalogue is sized to guarantee full utilisation is always recoverable from a published combination.

## PC vs SU class distinctions

| Class | Floor plate | Floor count | Tile-family preference |
|---|---|---|---|
| Professional Centres | 19,000–23,000 SF | 3–5 floors | Small + Medium (high climate-zone count) |
| Suburban Office | 17,000–21,000 SF | 6–9 floors | Small at ground; Large for upper Corporate |

Suburban Office buildings are taller and slimmer; their Tile choices skew toward maintaining Private Office sub-types at all floor levels. The variation lives in Special Tiles and Building Width, not in the Key Plans themselves.

## See also

- [[bim-floor-plate-methodology]]
- [[bim-floor-plate-tile-combinations]]
- [[bim-private-office-key-plans]]
- [[bim-zone-depths-per-use-type]]