Calculation

Loads, sizing, and capacity calculations tied to policy — every value cites the clause and version it derives from.

What it is

The single most policy-sensitive module in design. Structural loads, MEP loads, transformer sizing, pump capacity, HVAC heat load, diversity factor application — all done against the org's policy library (MEP-04 HVAC, MEP-07 Electrical, structural policy). Every calculation result carries the policy clause and version it derives from. Deviations require explicit approval. A policy update propagates to all open calculations.

Inputs

Triggers

·Concept design approved in M07 — calculation kickoff
·New drawing revision published in ACC
·policy version update (MEP-04, MEP-07, structural)
·Calculation review cycle by discipline head
·Deviation requested by consultant against policy

Data reads

·Project segment (drives MEP-07 diversity factor selection)
·Drawing version from M07 with model geometry and layout
·policy library — MEP-04 (HVAC), MEP-07 (Electrical), structural policy, façade policy
·Project configuration — areas, occupancy, equipment lists
·Previous-project calculation history for similar configurations

Artefacts consumed

·BIM model snapshot for quantity and geometry input
·Equipment schedule from consultant
·Connected-load list per discipline
·Project segment and product mix specification

Tools & Techniques

Methods

·Policy-anchored calculation — every value carries the clause and version it derives from
·Diversity factor application by segment (D1=0.45/0.48/0.50 for Gold/Platinum/Diamond)
·Multi-discipline reconciliation — structural feeds MEP feeds façade
·Deviation register with explicit approval workflow
·Auto-propagation of policy updates to all open calculation sheets

Policies

·MEP-04 V11 — HVAC design standards
·MEP-07 V17 — Electrical design standards including diversity factors
·Structural design policy with seismic and wind code references
·Façade structural and thermal policy
·Deviation approval policy — what requires Design Head, what requires MD

Decision rules

·Every calculation result cites its policy clause and version
·Policy deviation requires explicit approval — silent deviations rejected
·Cross-discipline conflict resolved before sign-off, not after
·Sign-off requires discipline-head review, not just consultant submission

Outputs

Artefacts produced

·Discipline-wise calculation sheets with policy citations
·Sizing summary feeding BOQ (loads, capacities, equipment specifications)
·Deviation register with approvals
·Policy citation log per project

Data writes

·Project calculation record updated per discipline
·Sizing summary feeds M10 BOQ generation
·Policy citation history feeds the standards library

Downstream triggers

·Sizing outputs trigger BOQ generation in M10
·Equipment specifications feed spec library reference in M09
·Sized loads drive procurement requirements in M14
·Policy update propagates re-validation across all open calculations

Stakeholders

Structure consultantStructural load and sizing
MEP consultantMEP loads and equipment sizing
Façade consultantFaçade load and panel sizing
MEP DesignPolicy compliance review
Standards teamPolicy authoring and maintenance
Design HeadCalculation sign-off and deviation approvals

The flow

01Structural load calculations — dead, live, wind, seismic
02Structural sizing — slabs, beams, columns, foundations
03MEP load calculations — connected load, demand load per MEP-07
04Transformer and DG sizing — diversity factors D1, D2, D3 from policy
05Pump capacity calculations
06HVAC heat load per MEP-04
07Diversity factor application — segment-specific D1 (0.45/0.48/0.50)
08Calculation sign-off with policy citations

State change

Before

Calculations done in vendor spreadsheets; deviations from policy not flagged; assumptions invisible.

After

Every value cites the policy clause; deviations require approval; policy updates propagate.

Real-world example

Worli MEP-07 calculation. Connected load 2,840 kW. Diversity factor D1 = 0.48 for Platinum segment (MEP-07 V17 clause 4.2). Demand load 1,363 kW. Transformer sizing 1,500 kVA per policy. Calculation signed off citing 12 policy clauses across MEP-04 V11 and MEP-07 V17.

Artefacts

·Calculation sheets per discipline
·Policy citation log
·Deviation register (with approvals)
·Sizing summary feeding BOQ

Pain today

Calculations come back from consultants in spreadsheets. The org's policy is referenced inconsistently. Deviations are silent — caught only by MEP review, often late. Same calculation re-derived every project.

Integrations

No external system integrations — module operates on internal records.