ITZA Worked Examples: 5 Real-World Scenarios
The best way to understand ITZA is to see it applied to realistic properties. Below are five worked examples covering common retail unit types, each showing the full calculation from floor areas to annual rent. All examples use a Zone A rate of £120 per square foot unless stated otherwise.
1. Standard High Street Unit
A typical rectangular shop on a busy high street, 20 feet wide with a total depth of 60 feet. Three clean zones, no ancillary space.
| Zone | Width × Depth | Area (sq ft) | ÷ Division | ITZA (sq ft) | Rent (£) |
|---|---|---|---|---|---|
| Zone A | 20 × 20 | 400 | 1 | 400.00 | £48,000 |
| Zone B | 20 × 20 | 400 | 2 | 200.00 | £24,000 |
| Zone C | 20 × 20 | 400 | 4 | 100.00 | £12,000 |
| Total | 1,200 | 700.00 | £84,000 |
700.00 ITZA × £120 = £84,000 per annum
Key takeaway: Although this property has 1,200 sq ft of floor space, its ITZA is only 700 sq ft — reflecting that the rear space is worth progressively less.
2. Deep Unit with Remainder
A narrow but very deep unit extending 100 feet from the frontage. Common in older high streets where medieval plot widths persist. 15 feet wide throughout.
| Zone | Width × Depth | Area (sq ft) | ÷ Division | ITZA (sq ft) | Rent (£) |
|---|---|---|---|---|---|
| Zone A | 15 × 20 | 300 | 1 | 300.00 | £36,000 |
| Zone B | 15 × 20 | 300 | 2 | 150.00 | £18,000 |
| Zone C | 15 × 20 | 300 | 4 | 75.00 | £9,000 |
| Zone D | 15 × 20 | 300 | 8 | 37.50 | £4,500 |
| Remainder | 15 × 20 | 300 | 16 | 18.75 | £2,250 |
| Total | 1,500 | 581.25 | £69,750 |
581.25 ITZA × £120 = £69,750 per annum
Key takeaway: Despite having 25% more floor area than the standard unit above (1,500 vs 1,200 sq ft), this property produces 17% less rent (£69,750 vs £84,000). The extra depth adds area but relatively little value — a classic illustration of why ITZA exists.
3. Wide Shallow Unit
A modern unit with a 40-foot frontage but only 30 feet deep. Extends into Zone B but no further. Common in purpose-built shopping centres and parades.
| Zone | Width × Depth | Area (sq ft) | ÷ Division | ITZA (sq ft) | Rent (£) |
|---|---|---|---|---|---|
| Zone A | 40 × 20 | 800 | 1 | 800.00 | £96,000 |
| Zone B | 40 × 10 | 400 | 2 | 200.00 | £24,000 |
| Total | 1,200 | 1,000.00 | £120,000 |
1,000.00 ITZA × £120 = £120,000 per annum
Key takeaway: Same total area as the standard unit (1,200 sq ft) but a much higher ITZA (1,000 vs 700) and rent (£120,000 vs £84,000). The wide frontage concentrates more area in the high-value Zone A, demonstrating why frontage width is so prized in retail.
4. Unit with Basement and First Floor
A mid-terrace shop with a standard ground floor plus a basement used for storage and a first floor used as office/staff space.
| Zone | Area (sq ft) | ÷ Division | ITZA (sq ft) | Rent (£) |
|---|---|---|---|---|
| Zone A | 500 | 1 | 500.00 | £60,000 |
| Zone B | 500 | 2 | 250.00 | £30,000 |
| Zone C | 300 | 4 | 75.00 | £9,000 |
| Ground floor | 1,300 | 825.00 | £99,000 |
| Floor | Area (sq ft) | ÷ Division | ITZA (sq ft) | Rent (£) |
|---|---|---|---|---|
| Basement (storage) | 600 | 15 | 40.00 | £4,800 |
| First floor (office) | 500 | 10 | 50.00 | £6,000 |
| Ancillary total | 1,100 | 90.00 | £10,800 |
Total ITZA = 825.00 + 90.00 = 915.00 sq ft
Total Rent = £99,000 + £10,800 = £109,800 per annum
Key takeaway: The ancillary areas add 1,100 sq ft of space but only 90 sq ft of ITZA and £10,800 of rent — about 10% of the total. The division factors for ancillary space (1/10, 1/15) reflect that these areas contribute far less to a retailer's trading potential than ground floor frontage.
5. L-Shaped Unit with Adjustments
An irregular L-shaped unit on a secondary pitch. The unit narrows significantly beyond Zone A. Adjustments are applied for the irregular shape and the secondary position. Zone A rate for this location is £80 per square foot.
| Zone | Area (sq ft) | ÷ Division | ITZA (sq ft) | Rent (£) |
|---|---|---|---|---|
| Zone A | 450 | 1 | 450.00 | £36,000 |
| Zone B | 250 | 2 | 125.00 | £10,000 |
| Zone C | 180 | 4 | 45.00 | £3,600 |
| Total | 880 | 620.00 | £49,600 |
| Adjustment | Applies To | Rate | Amount (£) |
|---|---|---|---|
| Shape (L-shaped, reduced display) | Whole Floor | -10% | -£4,960 |
| Frontage (narrow, 12ft) | Zone A | -5% | -£1,800 |
| Total adjustments | -£6,760 |
Unadjusted rent: £49,600
Adjustments: -£6,760
Adjusted rent: £42,840 per annum
Key takeaway: The adjustments reduce the rent by nearly 14%. Without them, the valuation would overstate the property's worth because the standard ITZA method assumes a regular, rectangular floor plan. Adjustments exist precisely to handle these real-world variations.
Try These Examples
Enter any of these scenarios into our free ITZA Calculator to verify the figures yourself. The calculator supports all five zone types, ancillary areas, and percentage-based adjustments — everything you need to replicate these examples and build your own.