## 3 Results
### Parametric Models of Typical Systems and Their Components
Whereas a traditional process would have involved drawing a detail section at 1:1 or 1:5 or even simply noting a catalogue reference for a profile and then a 1:20 drawing would have set out such items as desired, an HBIM model demands too much detail and is relatively inflexible. Simple assumptions that would be covered by trade knowledge such as the appropriate make-up of mitred junctions between joinery profiles are not easily created in parametric models made in REVIT(tm) which remains a clumsy tool in this respect (Figure 7). _Appl. Sci._**2020**, _10_, 1283  
Figure 6: (**A–C**) Middlesbrough Library vaulted ceiling structure models and section (**D–F**) Possil Park Library roofilights and section (main reading room), (**G**,H**) Loughborough Library ceiling orthophoto and model (main reading room). Generalisation and Grafting to Historic Standards  
Through the 3D model it is possible to obtain the volume and area measurements of the rooms and to analyse the original architectural choices especially concerning the lighting and ventilation of the rooms based on their size. Furthermore, from observing the internal treatment of roofs, it is possible to correlate the similarities with contemporary technical data on cast plaster ceilings. With the extent of the overall survey and the use of the matching techniques noted above, the similarities in the design choices of the vaulted ceilings are evident. It is possible to determine with authority the original architectural intentions in terms of building performance for ventilation. It is possible to provide pathways back through the trade literature of the time which significantly enhance our probably understanding of their substructure (Figure 8). From building the parametric models, dimensions between structural bays have been noted. For example; in Middlesbrough there are three squared ventilation grilles 0.5 m wide and placed at a distance of 5.1 m of each other. The apertures in each side feature 7 vertical windows placed in the lateral walls and each measuring H1730  
Figure 7: Possil Park Library Ventilation grille parametric family. mm \(\times\) W1670 mm with still height 6100 mm from the ground level and 3480 mm from the walkway level. In Loughborough, the main reading room ceiling is domed and hexagonal shape. The room area is 144.37 sqm with ceiling height of 6.73 m. The second reading room instead is a barrel-vaulted ceiling subdivided in three by two ceiling beams. The room area measures 43.14 sqm and curved ceiling height is of 4.83 m with a pitched skylight H1830 mm \(\times\) W2500 mm at its apex. These dimensions enable correlation to structural standards and manufactured components that can then be deemed to be likely belong to that heterogeneous system, despite it being hidden from view (Figure 6). With reference to a key text on fibrous plaster construction of the time, not only are the decorative details and construction identifiable but also the likely arrangement of the steelwork which can be compared with the spacings evident in the surveyed models [72]. Earlier work outlined the means to identify the likely manufactures of the plaster mouldings and glazing systems [73]. A deeper correlation relevant to all buildings of the era is possible through a comprehensive attempt to digitise historic trade literature. The Common Arrangement of Work Sections (CAWS) is a classification system based on work described trade-by-trade. That system had evolved from nineteenth century  
Figure 8: Details from Bankart: Modern plasterwork construction, casting and fixing: fibrous, solid and reinforced 1926 Source: Author. practices. Uniclass was introduced as a system in 1997 agreed between the professional bodies in the UK and incorporated CAWS [74]. As such it is theoretically possible to pair clauses from historic specifications, where they are available, to current forms for buildings of this era, short-circuiting some of the significant hurdles of HBIM integration in practice.