Why the residual method?
A bare buildable plot rarely has enough direct comparables (each plot is unique in location, surface, plot ratio, height limits, access, infrastructure). The residual method (RICS VPGA 10) circumvents this: it derives land value from the value of the completed project that could be built on it, less construction costs, financing, professional fees, and developer's margin.
It's THE method for valuing development land for investors, developers, lenders (secured lending), and estates. It requires real technical skill — plot-ratio analysis, urbanism review, BTP cost benchmarks, 24-36 month price forecasting.
The setup
Four MRE France children engage ReaConsult in March 2026 to value the plot inherited from their father (d. 2024):
- Location: Bouskoura Sud, 18 km from Casablanca centre, close to Casa-Marrakech A7 motorway.
- Surface: 2,400 m² ANCFCC-titled, surveyed 2022, recent boundary markers.
- Zoning: R+3 (residential, ground + 3 floors), plot ratio (COS) 1.6, site coverage (CES) 0.4 — small apartment block or clustered villas.
- Easements: no mortgage, one pedestrian right-of-way 2m to the north, no construction impact.
- Access: tarmac street, utilities at kerbside, mains sewerage.
Objective: fair valuation for (a) sale + partition among 4 heirs, (b) or buy-out by one heir. Technical arbitration required.
Residual method application (VPGA 10)
Step 1 — Optimal developable programme
With plot ratio 1.6 on 2,400 m², theoretical gross floor area (GFA) = 3,840 m². Applying a 0.83 usage ratio (circulation, cores, walls), effective saleable area = 3,187 m².
Retained programme: 28 apartments (3-4 bed, avg. 114 m²), 4 levels (G+3), mandatory underground parking.
Step 2 — Project revenue forecast
Step 3 — Deduct development costs
Step 4 — Residual calculation = land value
Methodology note: pre-acquisition residual is 21.6M MAD (gross-up from 3.22M via factor 1/(1 − 85%) accounting for the 6.5-8% buyer's costs and due-diligence overhead a developer would face). This is the market value of the land as-is.
Sensitivity tests
A rigorous VPGA 10 always tests value sensitivity to assumptions. Tested scenarios:
- Output price +5% (14,175 MAD/m²) → land +18% = 25.5M MAD
- Output price −5% (12,825 MAD/m²) → land −19% = 17.5M MAD
- Construction costs +10% → land −15% = 18.3M MAD
- Developer's margin 15% (vs 18%) → land +10% = 23.8M MAD
- Finance rate 8% (vs 7%) → land −2.5% = 21.05M MAD
Valuation range: 17.5 - 25.5M MAD. Central retained: 21.6M MAD.
Outcome
- April 2026 — 48-page signed report. Moudawana applies: 4 heir-children = equal shares (no surviving spouse).
- May 2026 — Market sourcing via local developer invited to offer. Received 22.3M MAD from a developer with existing area due diligence.
- June 2026 — Sale closed at 22.3M MAD (+3% vs central retained), net partition ~5.35M MAD per heir.
Take-aways for landowners
- Without a VPGA 10 valuation, under-valuation risk is massive — opportunistic buyers typically offer 30-40% below true residual value.
- Plot ratio and site coverage are decisive — same surface can vary 3x in value by zoning. Always check the Plan d'Aménagement Urbain (PA) before selling.
- Location beats surface — a 1,000 m² plot in CFC often exceeds a 3,000 m² plot in Sidi Maarouf.
- Developer margins are negotiable — high-demand plots can sell above residual method.
- Anticipate zoning changes — an R+2 plot today might become R+4 tomorrow. ReaConsult reports flag these upsides.
Have a plot to value, sell or partition?
Residual method VPGA 10. Court-admissible report. Quote within 24h.