Now Live · Brunei Green Building

Smart tools for
greener buildings

OptiSim builds calculation and certification tools for the built environment. Start with the BAGUS Certification Calculator — Brunei's first end-to-end green building assessment platform.

Built for Architects Consultants Developers
optisim.app — BAGUS Calculator

BAGUS Certification Calculator

📁 ABCi HQ Building · Brunei Darussalam

⚡ Part 1: Energy
💧 Water
🌳 Environment
📊 Summary
⚡ Energy Score: 72.0 / 105 pts  ·  🟡 In progress
1.1 Overall Thermal Transfer Value 15.0 / 15
1.2 Air Conditioning System 22.0 / 28
1.3 Building Design 18.0 / 28
🏅 BAGUS Gold · 87 / 200 pts 43.5%
Evidence uploaded · 18/22 criteria
🏅 BAGUS Gold — on track

Everything you need
in one place

From scoring to submission — OptiSim handles the complexity so you can focus on designing better buildings.

Live Score Calculation

Inputs update scores instantly across all five BAGUS parts. No spreadsheets, no manual totalling — see your rating in real time.

🎯

Target Rating Mode

Set a target — Certified, Silver, Gold, or Platinum — and see exactly how many points you need in each section to get there.

📎

Evidence Management

Upload supporting documents directly against each criterion. Track completeness across all 22 criteria with a single dashboard view.

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PDF Report Export

Generate a professional submission-ready report with score breakdown, gap analysis, mandatory requirements, and evidence register.

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Save & Resume

Save your project as a JSON file and reload it anytime. Evidence files are stored securely in the cloud — never lose your progress.

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Gap Analysis

Instantly see which sections need attention and how far you are from minimum requirements — so you can prioritise design decisions early.

BAGUS Calculator

Brunei's green building
certification, simplified

The BAGUS (Brunei Accredited Green Unified Seal) framework is Brunei's national green building rating system under the Ministry of Development. Navigating 200 points across 5 parts and 22 criteria is complex — OptiSim makes it manageable.

  • Full 2025 BAGUS guidelines — Parts 1 to 5
  • Mandatory requirements checker built in
  • Pro-rated scoring for A/C vs non-A/C floor areas
  • Submission-ready PDF with evidence register
  • Works for new non-residential buildings
Open the Calculator
🌱
BAGUS Certified
50 – 69 points
🥈
BAGUS Silver
70 – 84 points
🥇
BAGUS Gold
85 – 99 points
💎
BAGUS Platinum
100+ points

About OptiSim

Built by engineers,
for the built environment

OptiSim is a Brunei-based engineering consultancy specialising in building performance simulation and sustainable design. We build tools that make complex compliance and certification processes accessible to every design team.

The BAGUS Calculator is the first of a growing suite of tools — with energy simulation, daylighting analysis, and thermal comfort modules in development.

200
Maximum BAGUS points across 22 criteria
5
Scoring parts fully implemented
22
Criteria with evidence upload support

Ready to assess your building?

Start your BAGUS certification calculation in minutes — no installation, no account needed.

Launch the Calculator