Tool T–04 / Available
Cost pressure is never evenly distributed.
Stress the packages that are actually moving and see how escalation, specification, and value engineering affect the whole development case.
Cost plan assumptions
Stress individual packages rather than applying one blunt escalation factor.
Package stress
Where is the pressure coming from?
| Package | Cost share | Change | Baseline | Adjusted | Variance |
|---|---|---|---|---|---|
| Substructure | KES 50.4m | KES 50.4m | KES 0 | ||
| Frame & upper floors | KES 126.0m | KES 126.0m | KES 0 | ||
| Envelope | KES 60.5m | KES 60.5m | KES 0 | ||
| MEP services | KES 90.7m | KES 90.7m | KES 0 | ||
| Finishes & fittings | KES 100.8m | KES 100.8m | KES 0 | ||
| Preliminaries | KES 50.4m | KES 50.4m | KES 0 | ||
| External works | KES 25.2m | KES 25.2m | KES 0 |
Sensitivity matrix
Selling price × construction cost.
Each cell shows margin on cost after applying an additional project-wide construction movement and selling-price change.
| Cost / Price | -10% | -5% | 0% | +5% | +10% |
|---|---|---|---|---|---|
| -10% | 30.5% | 37.7% | 45.0% | 52.2% | 59.5% |
| 0% | 21.0% | 27.8% | 34.5% | 41.2% | 47.9% |
| +10% | 12.9% | 19.2% | 25.5% | 31.7% | 38.0% |
| +20% | 5.8% | 11.7% | 17.5% | 23.4% | 29.3% |
| +30% | -0.5% | 5.0% | 10.6% | 16.1% | 21.6% |
01
Inputs to prepare
- Base construction rate and gross floor area
- Package allocation across structure, envelope, services, finishes, preliminaries, and external works
- Package-level escalation or value-engineering adjustments
- Professional fees, contingency, selling price, and target margin
02
Outputs to interpret
- Adjusted construction cost
- Package-by-package cost movement
- Development margin after cost movement
- Required selling price to preserve target return
03
What this does not tell you
- Contractor pricing strategy and procurement route
- Programme delay, foreign exchange, and lead-time risk
- Detailed bill-of-quantities measurement
- Design interdependencies between packages
04
Read the result
A cost increase is rarely evenly spread. If services and envelope are doing the damage, the response is not a generic cut; it is a design, procurement, and specification conversation.
Use this frameworkNairobi Apartment Development Cost Guide 2026Use the calculator result alongside a practical cost guide for development assumptions, exclusions, and risk notes.Open cost guide →Method note
The base construction rate is allocated across seven packages. Each package can then be increased or reduced independently. Professional fees and contingency are calculated against adjusted construction cost.
The model excludes detailed cash flow, tax, escalation timing, procurement lead times, currency exposure, contractor risk, and package interdependencies. Use it to expose concentration and repricing risk before updating a full cost plan.
Questions / Method
A cost increase is a design and investment decision.
What is construction cost sensitivity analysis?
It tests how changes in individual cost packages or the overall construction budget affect total development cost, profit, margin, contingency, and required selling price.
Why analyse packages separately?
Structure, envelope, services, finishes, preliminaries, and external works respond differently to inflation, design development, procurement, foreign exchange, and specification decisions. One blended escalation rate can conceal the source of risk.
Is value engineering the same as reducing cost?
No. Good value engineering protects the project objective while changing design, specification, procurement, or construction logic. Unstructured cost cutting can damage revenue, durability, operations, or approvals.