Time for change
Since the initial release of masonry sections, content structure and editorial policies have developed considerably; and while the technical content is accurate and has been kept up to date, a comprehensive restructuring has become necessary. In addition, customer feedback has highlighted the need to streamline the process of masonry specification, and to improve usability.
A thorough review of the masonry content was conducted, which identified the following areas for improvement, which have been addressed in Update 12:
- System Outline clauses replaced for greater flexibility and clarity;
- System Outline clause items reorganized for a simpler, more intuitive user experience;
- Execution clauses relocated and rationalized;
- System Performance clauses rationalized.
1. System Outline clauses replaced
The System Outline clauses are the starting point for specifying masonry within NBS Create and, as such, the usability of these clauses is crucial to the user experience. The key focus for improvement was to make the process as intuitive and flexible as possible, so the review considered the limitations of the original methodology, and a new approach has been implemented in response.
The original methodology
The System Outline clauses that have been replaced described the entire width of the masonry wall: where there is a single leaf, a Single leaf clause would be used; where there is more than one leaf, a Multiple leaf clause would be used. The Multiple leaf clauses (with the exception of parapet and freestanding walls) supported three leaves by default, with the terminology varying between systems, adding further complexity. Where no 'intermediate' leaves were required (in the majority of cases), the item and sub-items would be parked or deleted. Where more than one intermediate leaf was required, the user was required to add their own clause item and sub-items, without the benefit of NBS guidance or suggested values.
Additionally, the wall was divided horizontally, with separate System Outline clauses for below dpc, dpc, above dpc and parapet. While this allowed for varying specifications in these locations, it added complexity to the specification process: either the same product was specified in multiple places, or partial clauses were created that only listed the products which differ, with no standard method to explain this within the specification.
This methodology required specifiers to choose from 11 possible System Outline clauses 
(.pdf, 0.3Mb), each with restrictive application, and hence complex titles:
- 110 Single leaf wall below damp proof course masonry system;
- 111 Single leaf masonry damp proof course system;
- 112 Single leaf wall above damp proof course masonry system;
- 113 Single leaf parapet wall masonry system;
- 114 Single leaf freestanding wall above damp proof course masonry system;
- 120 Multiple leaf wall below damp proof course masonry system;
- 121 Multiple leaf masonry damp proof course system;
- 122 Internal multiple leaf wall above damp proof course masonry system;
- 123 External multiple leaf wall above damp proof course masonry system;
- 124 Multiple leaf masonry parapet wall system;
- 125 Multiple leaf freestanding wall above damp proof course masonry system.
Furthermore, where masonry was used in combination with other constructions, the choice of systems was not straightforward. For example, when specifying a wall with an inner leaf of masonry and an outer cladding of lightweight rainscreen, specifiers could use either Single leaf clauses, or the intermediate or inner leaf items and sub-items of the Multiple leaf clauses; in each case using multiple clauses for Below damp proof course, Above damp proof course, etc.
The new approach
The new System Outline clauses are inspired by the proposed Uniclass2 classification methodology, which is currently under development by the UK government's Technology Strategy Board (TSB). This describes masonry systems on a vertical, leaf-by-leaf basis, each containing products from foundation to parapet. This offers the flexibility of combining systems within the masonry section to specify cavity/multi-leaf walls, or with systems in other sections for composite constructions, such as an internal timber frame with external brickwork. Future development of Create content will implement the Uniclass2 Elements table. Element Outline clauses will group together systems in the same way as System Outline clauses list constituent Products.
This simplified vertical leaf approach has reduced the number and complexity of necessary System Outline clauses specifiers now have to choose between only four (.pdf, 0.2Mb) , with straightforward titles:
- 150 Masonry external leaf system;
- 160 Masonry internal leaf system;
- 165 Masonry partition system;
- 170 Masonry freestanding wall leaf system.
For more information on selecting System Outline clauses with this methodology, including some illustrated examples for common masonry constructions, see Specifying masonry systems in NBS Create.
2. System Outline clause items reorganized
The second focus for improvement identified was the organization of clause items within the System Outline clauses. The new System Outline clauses provided an opportunity to reassess the specification workflow by collecting decisions together in a logical order, and avoiding repetition. A table comparing the new structure to the old can be found here.
Where previously, decisions for one product type were scattered over multiple clauses (below dpc, above dpc, etc.), and multiple locations within those clauses (inner leaf, intermediate leaf, outer leaf, and specialist applications within leaves for certain products), the new clauses group those decisions together. This allows products to be considered once per system, and prevents specifiers from having to jump back and forth in the process. The procedure is discussed in more detail in the article, Specifying masonry systems in NBS Create, which demonstrates how mortar products would be specified as an example.
3. Execution clauses relocated and rationalized
The third major improvement to the masonry content is the relocation and rationalization of Execution clauses. Initially, all Execution clauses were selected at System Outline clause level, but as NBS Create content has been developed, Execution clauses related to specific Products have been relocated, and are now selected within the Product clause they relate to.
This structure is particularly beneficial when considering masonry systems, where there can be over 100 associated Execution clauses. The previous structure posed a usability problem for specifiers; they were faced with a long list of Execution clauses to scroll through, many of which were related to specific products that they had not included in their specification.
The new arrangement means specifiers only have to choose from a limited selection of Execution clauses that are likely to be relevant, i.e. at System Outline level, only the clauses that relate to the system as a whole, and at Product level, only the clauses that relate to that specific product.
Further rationalization has taken place to remove duplicated clauses, combine similar clauses and remove redundancies. In total, the review of Execution clauses has reduced the list the user is faced with when composing their System Outline clause from 100+ Execution clauses down to a more manageable and intuitive 20 (maximum).
4. System Performance clauses rationalized
The final change to the masonry content affects the System Performance clauses. The workflow for specifying by performance has been developed since the masonry content was first authored. In particular, in June 2014 a new Create section was introduced: 05-20-60 Whole Building Performance. This section collects together all performance requirements that relate to the building as a whole, rather than specifying them repeatedly in separate system sections. In addition, specialized performance clauses have been developed in other sections, and the Project Management sections have developed in scope.
Following the review, clauses duplicated in the Whole Building Performance section, in other system sections, or in Project Management sections have been removed or revised in line with the current approach and, as with the execution clauses, duplicated clause content has been removed or combined with similar clauses, and redundant clauses have been deleted. The review has reduced the System Performance clause count from 20 to 10, simplifying the process of specifying masonry by performance.
Managing the transition
When beginning a new specification, or populating an Office Master with new clauses, only the new System Outline clauses will be used. However, where users have project specifications or Office Masters that include the superseded masonry System Outline clauses, they are advised to proceed with caution to avoid data loss or unusable specifications. More specific information for managing the transition can be found in the article, Specifying masonry systems in NBS Create.
