Design Input Checklist
What to gather before commissioning outsourced electrical design — complete inputs mean faster delivery and a lower quote.
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.
⏚ 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.