XLR8 Case Study

Brittleware Farm — Electrical Load Assessment for Residential Development

Horley, Surrey

Project Overview

XLR8 MEP Design Ltd was appointed by a residential developer to undertake a detailed electrical load calculation and demand assessment for an 8-unit new-build residential scheme at Brittleware Farm, Horley.

The purpose of the study was to define the required incoming electrical supply capacity and provide a clear technical basis for submission to the Distribution Network Operator (DNO).

Client Requirement

The client required a structured engineering assessment to:

• Determine electrical demand across all proposed dwellings
• Incorporate modern loads including heat pumps and EV charging
• Apply appropriate diversity across the development
• Establish a realistic maximum demand for the incoming supply application

Scope of Services

XLR8 MEP Design Ltd provided:

• Full electrical load calculations for all 8 dwellings
• Assessment of:
  • Lighting and small power
  • Heating and hot water systems
  • EV charging demand
  • cooking loads
• Inclusion of landlord electrical supplies (external lighting and spare capacity)
• Development of ADMD (After Diversity Maximum Demand) calculations
• Preparation of a structured demand model suitable for DNO submission

Development Overview

The scheme comprised:

• 8 residential units
• Electrified systems including:
  • heat pumps
  • EV charging provision

Each dwelling demonstrated a diversified load typically in the region of:

• ~20–22 kVA per unit

Key Engineering Findings

The analysis identified:

• Significant reduction in total demand through diversity application
• Realistic modelling of:
  • Heat pump operation
  • EV charging behaviour
• Overall diversified site demand in the region of:
  • ~60–95 kVA depending on diversity assumptions

This formed a robust and defensible basis for the incoming supply requirement.

Engineering Insight

A key element of the project was balancing:

• Individual dwelling electrical demand, and
• Diversified demand across the development

Without applying engineering-led diversity:

• Supply requirements would be overstated
• Infrastructure costs would increase unnecessarily

Accurate ADMD modelling is critical for residential developments incorporating electrified heating and transport.

Outcome

XLR8 MEP Design Ltd delivered a clear and structured electrical demand assessment which:

• Defined the required capacity for the main incoming supply
• Supported the developer’s DNO application
• Enabled informed decision-making at an early project stage

Project Value

This project demonstrates XLR8’s role in supporting residential developments through:

Practical, data-led electrical design that enables projects to move forward efficiently and cost-effectively.

Planning a Similar Development?

If you are developing a residential scheme and need clarity on electrical capacity, heat pump integration, or DNO requirements, XLR8 MEP Design Ltd can provide clear, technically robust support.

Contact us to discuss your project

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