Start with the experience the project should support: a waiting chair with a view, a lounge with a little shelter, or a planted edge that staff can actually service. A business case must explain what will be delivered, what it costs to keep it working, and which values are estimates rather than cash.
Separate the cost from the hoped-for outcome
Before assigning value to an intervention, use the biophilic design introduction to distinguish views, materials and spatial experience from a planting-only scope.
Obtain an installation quote and an operating allowance. Include container fit, water containment, access, plant replacement and staff time. If a project borrows an outdoor view or uses glare control rather than adding planting, budget that design move on its own terms.
Salary multiplied by an assumed productivity change is estimated economic value. It is not automatically a payroll saving. A hypothetical increase in hotel revenue is not profit: it also needs evidence about demand, attribution and delivery costs.
What the office research can tell you
Across three field experiments in commercial offices in the Netherlands and the UK, researchers studied how adding plants affected employees’ perceptions of their workspace and their performance. One experiment found improved perceived productivity; another found improved performance on an objectively measured task. The findings apply to the workplaces and tasks studied.
The setting matters. This research does not establish the return for a particular building or validate hotel rate increases, patient recovery savings or the fixed factors in our calculator. Treat it as a reason to investigate a workplace decision, not a universal multiplier.
An illustrative office scenario
The calculator starts with 10,000 SF, 50 occupants, $75,000 average salary, Enhanced investment at $20/SF and vendor care. These are example inputs, not a benchmark. The unchanged model gives:
- Installation: 10,000 × $20 = $200,000.
- Annual care: 15% × $200,000 = $30,000.
- Productivity value: 50 × $75,000 × 4% = $150,000.
- Absence value: ($75,000 ÷ 260) × 5 days × 50 × 10% = $7,211.54.
- Retention value: 50 × 15% turnover × $15,000 × 10% reduction × 25% = $2,812.50.
- Estimated annual economic value: $160,024.04; after care: $130,024.04.
- Illustrative simple payback: $200,000 ÷ ($130,024.04 ÷ 12) = 18.46 months, rounded up to 19 in exported summaries.
Every benefit factor above is a fixed model assumption, not a verified outcome. The five-year projection grows value by 3% and care by 2%, without discounting or tax. Its growing breakeven calculation is different from simple payback; an existing 60-month cap can display even when no five-year breakeven is found.
Which assumption would change the decision?
Compare vendor and in-house care using the available switch. Then vary the size or relevant salary and revenue inputs. The tier factors are fixed, and switching tiers changes cost and benefits together. Healthcare and education currently share the office model; they do not model clinical or educational outcomes.
Before committing, identify what would count as success and what evidence is already available. Keep facilities staff involved: a mature canopy, a replacement route and a watering visit belong in the same decision as the first installation.
Explore the illustrative scenario tool and its full assumptions · Compare maintenance arrangements