The Building Safety Act golden thread is a 3D evidence problem
Higher-risk buildings now need a verifiable, accessible information record. PDFs and spreadsheets do not pass that test. Photoreal 3D digital twins do.
Higher-risk buildings now need a verifiable, accessible information record. PDFs and spreadsheets do not pass that test. Photoreal 3D digital twins do.
For the last decade, the question a building owner faced from regulators sounded like this: do you have a fire risk assessment on file? A folder of PDFs and a signed cover sheet were usually enough.
The Building Safety Act 2022 (BSA) and the Building Safety Regulator (BSR) have changed the question. For higher-risk buildings — currently residential buildings of 18 metres or more, or seven storeys or more, with two or more residential units — the question is now: can you show us, in real time, the current state of every safety-critical asset, who installed it, when it was last inspected, and how that maps to the as-built fabric of the building?
That is the golden thread. The legislation deliberately does not prescribe a file format. The BSR's published guidance calls for information that is "accurate, easily understandable, can be accessed easily by those who need to know and is kept up to date." PDFs and spreadsheets struggle with all four of those tests once a building is occupied and changing.
We work alongside Principal Accountable Persons and Building Safety Managers every week. Three recurring failure modes show up:
OnXR captures the building as it actually is — a walk-through with an iPhone Pro or our 360° LiDAR + 8K RGB handheld scanner produces a measurement-grade, photoreal 3D twin in under four hours per floor. The captured environment is automatically scanned for assets: doors, dampers, AOVs, fire alarm sounders, sprinkler heads, signage, riser cupboards, smoke vents and more, mapped against the BSA-relevant categories.
Each detected asset becomes a node in the twin. The node carries the photo evidence of its installation, the location to centimetre accuracy, the link to its O&M document, its last inspection date and its next due date. When the BSR — or an insurer, or a leaseholder — asks "show me the AOV serving the east stair on level 14", that node is one click away in a browser. No site visit. No PDF rummage.
Crucially, when the building changes, the twin can be re-captured. The previous twin is preserved, time-stamped and diffed against the new one. The golden thread becomes a timeline, not a snapshot.
For Principal Accountable Persons the most expensive part of BSA compliance is not the inspection itself; it is the cost of proving, again and again, what was inspected, by whom, and when. Spatial evidence collapses that cost. A captured twin is a deposition.
For asset owners with portfolios across multiple HRBs, the value compounds. The same baseline twin supports the safety case, the insurance survey, the FM asset register, the CDM 2015 design risk register, and the ISO 19650 information container.
The legislation will not relax. Expect HRB thresholds to extend, and expect the BSR to lean further into expecting a live, queryable record rather than periodic paperwork. The buildings that will struggle are not the ones that have the most assets; they are the ones whose information cannot keep up.
We typically start with a baseline scan of a single representative building: stair cores, plant rooms, residential floor, refuse store, riser cupboards. The output is the as-is twin, the auto-detected asset register, and a gap report against the building's existing fire and safety documentation. From there, the operating model — who captures, who reviews, who signs off — can be designed against real evidence rather than a job description.
The golden thread is not a software question. It is an evidence question. If the evidence is photoreal, accurate, accessible and current, the rest follows.
