Design Input Checklist — Earthing Studies & Cable Calculations | Sparklineeng

Incomplete input data is the number one cause of delay and cost creep in outsourced design work. Use this checklist to gather what your designer needs — whichever consultancy you use.

📐 Which RIBA stage are you at?

The RIBA Plan of Work 2020 runs from Stage 0 to Stage 7. Expand the stage your project is at to see the electrical services deliverables expected, and tick Yes / No / N/A against each as a design-deliverables audit. Structured on the BSRIA BG 6 Design Framework for Building Services and CIBSE guidance; indicative — verify against your agreed Schedule of Services. Most detailed electrical design lands at Stage 3–4.

0 Stage 0 · Strategic Definition — are you still deciding whether the project goes ahead?

Stage purpose. The business case and strategic brief are established and the client decides whether — and on what basis (new build, refurbishment, extension) — to proceed.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Supply & capacity
High-level electrical load appraisal for the options being considered
Review of available / existing supply capacity and likely DNO connection or reinforcement
Space & budget
Space allowances for main electrical plant (substation, main switchroom, standby generator)
Order-of-cost / feasibility input to the business case
Strategy & risk
Site-wide electrical constraints and opportunities flagged (resilience, EV charging, renewables)
Sustainability / energy ambitions noted to steer the electrical strategy

1 Stage 1 · Preparation & Briefing — have you fixed the brief, site information and budget?

Stage purpose. The project brief, feasibility studies, site information, budget and programme are confirmed and the project team is assembled.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Brief & responsibilities
Electrical section of the project brief / employer's requirements
Design-responsibility matrix and scope for the electrical package
Load & supply
Preliminary load estimate and standby / resilience requirements
Early DNO enquiry / budget point-of-connection request
Surveys & standards
Review of site surveys, existing installations and constraints
Applicable standards confirmed (BS 7671, BS EN 62305, BS 5266, BS 5839, CIBSE guides)

2 Stage 2 · Concept Design — are you developing the architectural concept and services strategy?

Stage purpose. The architectural concept, outline specification, project strategies and cost plan are prepared and signed off.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Reports & strategy
Outline electrical strategy / design narrative (Stage 2 report)
Estimated maximum demand and main supply methodology (LV / HV, metering)
Drawings
Concept single-line diagram (intake to main distribution)
Outline lighting, small power and containment concept layouts
System concepts
Outline lighting and lighting-control concept with target lux levels
Outline fire detection & alarm and emergency-lighting concept
Outline earthing and lightning-protection (BS EN 62305) approach
Space & cost
Main plant, switchroom and riser space requirements
Elemental / budget cost input to the cost plan

3 Stage 3 · Spatial Coordination — is the design being coordinated across disciplines?

Stage purpose. The design is spatially coordinated across disciplines, strategies and the cost plan are updated, and the design is frozen at the end of the stage.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Calculations & schedules
Elemental load assessments and diversified load schedules
Fault-level calculations; preliminary cable sizing and volt-drop checks
Drawings & schematics
Developed single-line diagrams and distribution schematics
Lighting, small power and containment layouts coordinated with structure and other services
Plant room, switchroom and riser layouts fixed spatially
Systems & supply
Fire alarm, emergency lighting and specialist systems (data, security) developed
Earthing and lightning-protection design updated
Formal DNO application / supply agreement progressed
Reports
Stage 3 report; design coordinated and frozen

4 Stage 4 · Technical Design — do you need construction-ready information?

Stage purpose. All design information is completed and specifications plus specialist / subcontractor design are produced ready for construction.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Calculations
Full cable sizing and protective-device selectivity / discrimination to BS 7671
Fault-level, volt-drop and earth-fault-loop impedance verification
Lighting and emergency-lighting calculations (lux, uniformity, escape routes)
Earthing and lightning-protection risk assessment & design (BS EN 62305)
Drawings & schematics
Final single-line diagrams and distribution schematics
Coordinated lighting, small power, containment and fire-alarm layouts
Builder's-work and containment coordination drawings
Schedules & specifications
Distribution board, luminaire and equipment schedules
Electrical specifications (general & particular)
Tender / construction-issue documentation

5 Stage 5 · Manufacturing & Construction — are you on site or building?

Stage purpose. Manufacturing and construction proceed in line with the construction programme and design queries are resolved.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Design support
Respond to technical queries / RFIs and design-change requests
Review contractor / subcontractor design-portion and installation drawings
Review manufacturer / specialist submittals and samples against the specification
Change control
Reissue calculations, schedules and drawings for site changes / value engineering
Keep the single-line diagram and load schedule current as the design develops
Site & quality
Site inspections and design witnessing as required
Witness / review testing and commissioning as installation completes

6 Stage 6 · Handover — is the building being handed over?

Stage purpose. The building is handed over, aftercare is initiated and the building contract is concluded.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Records
As-installed drawings, schematics and calculations
Input to O&M manuals and the health & safety file
Verification & close-out
Review of inspection, testing and certification results (BS 7671 EIC, commissioning records)
Support snagging and defect close-out; witness demonstrations if required

7 Stage 7 · Use — is the building occupied and in use?

Stage purpose. The building is operated, maintained and occupied, with post-occupancy evaluation.

Design deliverables audit — tick Yes / No / N/A for each item:

Electrical deliverable	Yes	No	N/A
Aftercare
Post-occupancy support and aftercare
Fine-tuning of lighting and controls in response to actual occupancy
Ongoing
Re-assessment if loads, occupancy or the supply change
Input to periodic inspection & testing (EICR) and maintenance regimes

References: RIBA Plan of Work 2020 — overview & free PDF · ribaplanofwork.com · BSRIA BG 6 — Design Framework for Building Services. Stage names and purposes follow the RIBA Plan of Work 2020 (which is discipline-agnostic — RIBA does not itself publish an electrical deliverables list). The electrical deliverables audited above are structured on the BSRIA BG 6 framework and CIBSE guidance; they are indicative typical outputs, not a verbatim reproduction, and the exact split varies by project and appointment.

⏚ For an Earthing Study

Site layout drawing (DWG or PDF) showing substation / electrode locations
Soil resistivity survey results — Wenner or Schlumberger, with probe spacings and date
Earth fault level and fault clearance time (from the DNO or protection study)
Supply earthing arrangement and DNO connection details / offer letter
Existing earthing system drawings, if working on a live or brownfield site
Nearby third-party infrastructure within ~100 m — rail, pipelines, telecoms, fences
Applicable specifications — client spec, National Grid, LU, HS2, ENA documents
Programme deadline, especially any DNO submission date

⚡ For a Cable Calculation Pack (ProDesign)

Single-line diagram or schematic (even a marked-up sketch helps)
Load schedule with ratings and any diversity assumptions
Cable routes and lengths, or a layout drawing to measure from
Supply details — transformer rating, fault level, earthing system (TN-S, TN-C-S…)
Installation methods — tray, ladder, clipped, buried — and grouping
Preferred cable types and protective device manufacturer/ranges
Client specification and applicable project standards
Existing ProDesign / Amtech project files, if the design is being updated

💡 For a Lighting Design (DIALux)

Floor plans (DWG preferred, PDF workable) with room names
Ceiling heights, and surface finishes/reflectances if known
Target lux levels or the standard to design to (BS EN 12464, client spec)
Preferred luminaire manufacturer or wholesaler ranges
Emergency lighting requirements and escape routes, if in scope

Missing some of it? Send what you have — we'll tell you exactly what's still needed and whether we can proceed with stated assumptions. See our pricing guide for how input completeness affects cost.