BIM Checker is an enterprise-grade automated digital compliance platform built on the Bentley iTwin infrastructure. It translates complex statutory building regulations, British Standards (BS 8300-2, BS 9999), and UK healthcare standards (NHS Health Building Notes and Health Technical Memoranda) into deterministic, executable analytical queries executed directly against live iModel changesets.
Rather than relying on sample exports, disconnected spreadsheets, or approximate local CAD checks, BIM Checker queries the live federated iModel container using ECSQL and precision 3D spatial evaluators.
Healthcare facilities have some of the most stringent spatial, clinical, and life-safety criteria in the built environment. In the Hospital (UK_NHS) configuration profile, BIM Checker evaluates 13 statutory rules organized into 5 primary engineering domains:
| Rule Code | Domain | Title | Statutory Standard | Required Threshold |
|---|---|---|---|---|
HOSP-PLN-001 |
Planning & Areas | Hospital GFA Reconciliation & Schedule of Accommodation | NHS HBN 00-01 cl. 3.12 / RICS IPMS 3 | $\le \pm 2.0%$ variance vs 25,000 m² planned brief |
HOSP-PLN-002 |
Planning & Areas | HBN 00-01 Clinical Space Floor Area Brief Compliance | NHS HBN 00-01 cl. 3.12–3.28 / HBN 04-02 | Consult/Exam $\ge 12.0\text{ m}^2$, ICU $\ge 26.0\text{ m}^2$, OR $\ge 40.0\text{ m}^2$ |
HOSP-PLN-003 |
Planning & Areas | NHS HBN 00-01 In-Patient Bedroom & Sanitary Space Brief | NHS HBN 00-01 cl. 3.14 & BS 8300-2 | Single Bed $\ge 19.0\text{ m}^2$ (excl. en-suite), WC $\ge 4.5\text{ m}^2$ |
HOSP-EVAC-001 |
Evacuation & Routes | Clinical Door Effective Clear Opening ("900mm Illusion") | NHS HBN 00-04 cl. 4.2.1 / BS 8300-2 cl. 8.4 | Bed $\ge 1.20\text{ m}$ (1,200 mm), General $\ge 0.90\text{ m}$ (900 mm) |
HOSP-EVAC-002 |
Evacuation & Routes | Hospital In-Patient Corridor Clear Circulation Width | NHS HBN 00-04 Circulation / BS 8300-2 | Bed-Passing Circulation Width $\ge 2.00\text{ m}$ |
HOSP-EVAC-003 |
Evacuation & Routes | Hospital Egress Travel Distance (Progressive Horizontal) | NHS HTM 05-02 Firecode cl. 3.12 / BS 9999 | Direct $\le 30.0\text{ m}$, Dead-End $\le 15.0\text{ m}$ to refuge/stair |
HOSP-EVAC-004 |
Evacuation & Routes | Hospital Evacuation Stair Width, Riser & Goings | NHS HBN 00-04 / BS 8300-2 cl. 7.3 | Flight Clear Width $\ge 1.20\text{ m}$, Pitch $\le 33^\circ$ |
HOSP-CLR-001 |
Clearance & Gauging | Hospital Structural Soffit & Beam Headroom Clearance | NHS HBN 00-04 / HTM 03-01 | Habitable Clear Height $\ge 2.40\text{ m}$ to structural beams |
HOSP-CLR-002 |
Clearance & Gauging | Overhead MEP Ceiling Drops & Service Duct Headroom | NHS HBN 00-04 / HTM 03-01 | Minimum Clear Headroom $\ge 2.40\text{ m}$ under MEP drops |
HOSP-FIRE-001 |
Fire Safety (PCCC) | Sub-Compartment Fire Barrier & Door Rating Match | NHS HTM 05-02 Firecode cl. 4.10 / BS 9999 | Sub-compartments $\le 2,000\text{ m}^2$, Walls $\ge \text{EI 60}$, Doors $\text{FD60S}$ |
HOSP-FIRE-002 |
Fire Safety (PCCC) | Fire Barrier Full-Height Slab-to-Slab Integrity | NHS HTM 05-02 cl. 5.14 / Approved Doc B | Slab-to-soffit plenum barrier continuity ($\ge 3.20\text{ m}$) |
HOSP-ACC-001 |
Accessibility & Stairs | Healthcare Accessibility Ramp Gradient & Landings | BS 8300-2:2018 / Approved Doc M cl. 1.26 | Gradient $\le 8.33%$ (1:12), Turning circle $\ge 1.50\text{ m}$ |
HOSP-ACC-002 |
Accessibility & Stairs | Accessible Sanitary & Assisted Bathing Turning Circle | BS 8300-2:2018 / NHS HBN 00-01 | Unobstructed Turning Circle $\ge 1.50\text{ m}$ (1,500 mm) |
Every rule execution in BIM Checker transitions through a deterministic state machine:
The overall facility health score is calculated as a normalized ratio from $0.00$ to $1.00$:
$I_c = \frac{\sum_{i=1}^{N} w_i \cdot \text{StatusScore}(r_i)}{\sum_{i=1}^{N} w_i}$
Where:
Explore the dedicated documentation sections for complete mathematical definitions, ECSQL queries, parameters, defect templates, and authoring guidelines:
HOSP-PLN) — Gross floor area reconciliation, clinical space sizing, and inpatient ward brief compliance.HOSP-EVAC) — Clear door widths, bed transfer clearances, corridor pinch points, and progressive horizontal evacuation shortest-path calculation.HOSP-CLR) — Habitable headroom under structural downstand beams and overhead MEP service drops.HOSP-FIRE) — Sub-compartment fire ratings, door rating matching, and slab-to-soffit plenum continuity.HOSP-ACC) — Healthcare ramps and 1.50m sanitary turning circles.