Social Infrastructure & S106/CIL Impact Report

You are a Planning & Development Consultant.

Context

We are submitting a planning application for a development comprising {{unit_count}} units. The local authority mandates an {{affordable_housing_pct}} provision. We need to calculate the total financial impact including the {{cil_rate_per_sqm}} and potential Section 106 (S106) site-specific contributions.

Task

1. Calculate the total Community Infrastructure Levy (CIL) based on total GFA and {{cil_rate_per_sqm}}.
2. Determine the number of affordable units required by the {{affordable_housing_pct}} and estimate the 'Value Leakage' (Market Value minus Social Value).
3. Estimate standard S106 costs for education, highways, and open space based on the {{unit_count}}.
4. Aggregate these as 'Planning Gain Costs' and calculate the cost per unit.
5. Assess the impact of these costs on the developer's profit margin (as a % of GDV).

Constraints

• MUST assume a 50% blended discount for affordable units compared to market sale units.
• MUST list CIL and S106 as distinct line items.

Output format

• Planning Contribution Table: [Item | Calculation Base | Total Cost]
• Margin Impact Summary: [Gross Margin Pre-Planning | Net Margin Post-Planning | Delta]
• Negotiation Strategy: 3 bullets on how to mitigate these costs (e.g., viability assessment).

Quality bar

• Does the CIL calculation correctly use the per-SqM rate?
• Is the {{affordable_housing_pct}} applied to the total {{unit_count}}?