Evolution of the Acoustical Provisions within the Model National Building Code of Canada
Bibliographic record
Abstract
This paper explores the evolution of the National Building Code of Canada (NBCC). Starting in 1941, the NBCC required sound insulation of walls and floors between dwelling units to be sound transmission class (STC) 45. There were restrictions on the attachment of fixtures. Refuse chute construction was described. In 1956 references to compromising air leaks were introduced. In 1965, STC 45 performance was added for a variety of service rooms. ASTM E90-61T was introduced. Minor changes occurred in the 1970, 1975, 1977, 1980, and 1985 versions. In 1975, a table was added showing sound ratings of assemblies. In 1990, STC 50 was introduced along with an STC 55 provision for elevator shafts and refuse chutes. In 1995, a larger table of expected sound ratings was included. No significant changes occurred for the 1995 or 2005 versions. The 2010 edition saw language added for secondary suites where an STC 43 rating was stipulated. The 2015 version added in the option of demonstrating either an apparent STC (ASTC) performance of 47 or STC 50. Additional reference was made to ISO standards in regards to flanking paths. Future changes are being considered for impact insulation class (IIC), exterior noise control, and low-frequency sources.
Fetched live from OpenAlex and de-inverted. Abstracts are not stored in this database: the inverted indexes are 8.6 GB of the frame’s 9.3 GB of text, and the host has 13 GB free.
How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.005 | 0.018 |
| Meta-epidemiology (narrow) | 0.001 | 0.001 |
| Meta-epidemiology (broad) | 0.000 | 0.001 |
| Bibliometrics | 0.005 | 0.006 |
| Science and technology studies | 0.005 | 0.003 |
| Scholarly communication | 0.006 | 0.002 |
| Open science | 0.003 | 0.001 |
| Research integrity | 0.001 | 0.002 |
| Insufficient payload (model declined to judge) | 0.009 | 0.003 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".