A few M&E questions

Part A

Scope

Already scoped

Simple counting (fixtures, outlets, light points) is the safest starting point. Circuit sizing, DB sizing, and HVAC capacity are being treated as real design decisions — not something we'll auto-calculate. Plumbing fixture counts (WC, wash-hand basin, shower, bath, sink, floor drain, tap) are confirmed as directly countable from drawings. Septic/soakaway and HVAC sizing are deferred as specialist territory for now.

Do QS/contractors in your experience usually estimate basic electrical/plumbing themselves, or is it always handed to an M&E specialist?

They estimate it themselves

Always a specialist

Depends on the project

Is there a Nigerian-specific standard or code this kind of estimating should follow?

Part B

Electrical

Already scoped

Points-per-circuit and distribution-board sizing are being treated as real design decisions, not something we'll auto-default from a rule of thumb.

Is there a rule-of-thumb allowance for socket outlets / light points per room type that you actually use for a quick estimate — or is it always bespoke?

e.g. "a standard bedroom gets around N sockets, M light points"

A real convention exists

Always bespoke

When you measure a cable or conduit run, is it the straight-line distance, or is there a standard allowance for routing, bends, and vertical drops?

What wastage allowance would you apply for cable, conduit, and other conductors — one flat %, or does it vary by material?

Part C

Plumbing / Mechanical

Already scoped

Fixture counting is confirmed as drawing-derived and safe to build. HVAC sizing is being kept fully out of scope — always treated as needing a real heat-load calculation.

Are there common pipe sizes and materials worth having as standard preset options (like standard block sizes are presets for walls)?

For water tank sizing, is there a rule of thumb (e.g. litres per bedroom) usable for a quick estimate, or does it always need a real occupancy/storage-day calculation?

A rule of thumb works

Always needs real calculation

You

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A few questions on electrical & plumbing estimating

Thank you