NBS publishes a range of products for specification of building work. A question that is often asked is "which version of NBS should I use to specify a small (or medium, or large) building that I am designing"? For small building works, the subject of this article, NBS publishes a range of products for specification.

'Small works' is a convenient, if rather vague, term for work that may be small in scale, small in value or 'small' in terms of complexity. On the latter point, it should be borne in mind that a housing estate may be large in size and high in value, but each house type is relatively simple and repetitive and, taken individually, may be considered 'small work' – although, of course, the overall site infrastructure will be more complex.


The following table attempts to identify key differences between the small works specification products, and is followed by brief explanations of the terms used. It will be seen that in selecting a product there is more to consider than simply the size or type of building to be specified.

Product Formats Acquisition Stand-
Work sections Contracts Clause types Clause selection
NBS Domestic Specification online o one off purchase for each project yes 23 (incl. M&E) 6 proprietary, limited generic edit down from full section content
NBS Domestic Specification (paper) p1 one off purchase for each project yes 20
(incl. M&E)
6 proprietary, limited generic tick and complete relevant clauses
NBS Building MW e, p2 annual subscription no 104
(incl. M&E)  
11 generic, proprietary edit down from full section content
NBS Scheduler e annual subscription yes 114
(incl. M&E)
19 generic, proprietary drag and drop into blank document

1 The content of the paper version of the NBS Domestic Specification differs from that in the online version. Moving the product online has permitted an alternative approach allowing more detailed specification of products and execution.

2 Unlike NBS Domestic Specification, the clause content of the electronic and paper versions of NBS Building MW is essentially the same.

Terms used


  • e: An electronic programme available for PCs using Microsoft Windows (generally Windows 2000 or XP). System requirements for each product are detailed on the NBS website.
  • o: An electronic online programme hosted on the NBS servers. Access is through web browser software from any platform (Linux, Macintosh, Windows).
  • p: A paper (hardcopy) version is available. For NBS Building MW this version also includes clauses for word processing programmes (on CD ROM) able to be used with a variety of computer operating systems, including Macintosh.


  • One off purchase: A good option for users who have a single domestic project, or very occasional small domestic projects.
  • Annual subscription: Suitable for users who have a fairly regular turnover of small works projects.


  • yes: The product creates or contains a priceable document that can be issued to contractors at tender stage to allow direct pricing of elements of the construction (foundations, walls, floors etc.).
  • no: The product does not create or contain a pricing document for elements of construction. Additional work is required (outside the NBS product) to create a bill of quantities or schedule of work for use with the specification.

Work sections:

  • The value in the table indicates the number of different work sections covered by each product. Since each work section covers a different product area or work type this gives a rough indication of the capability of each NBS product to specify a wide range of work. Note however that scope of sections varies somewhat between products.


  • Each NBS specification product contains Contract particulars or Preliminaries content relating to the use of the product with a number of different forms of contract. Selection of an NBS specification product may partly be governed by the availability of preliminaries relating to particular forms of contract.

Clause types:

  • In general NBS specification products may be used either for proprietary (named manufacturer) or generic (defined product properties) specification.

Clause selection:

  • The 'authoring' process for clause selection varies between products. NBS Building MW presents full section content to the specifier to be edited down to suit the project (in the paper version this requires striking out unwanted content). NBS Scheduler requires content to be added to an essentially blank screen. NBS Domestic Specification (paper version) requires selection of appropriate clauses by completion of check boxes, whilst the online version requires selection and completion of the appropriate clauses to suit the project.

The Small Works Specification products

NBS Domestic Specification:

Online version:
NBS Domestic online is the first venture by NBS into online specification. After making a small payment, a project specification can be completed online, then published as a PDF and downloaded for issue to a builder for pricing.

The online specification tool contains a number of work sections, each relating to a particular trade or work type. The specifier selects those sections containing relevant material for the project. Each work section has a sequence of priceable 'System outline' clauses backed up by a series of related 'Products' clauses and 'Execution' clauses. Some work sections, principally those dealing with drainage and mechanical and electrical services, also contain several 'Completion' clauses relating to commissioning and testing requirements.

Any clause (and any item within a clause) can be selected or deselected for use as appropriate in the final specification document. A partially finished specification can be downloaded as a 'Draft' watermarked pdf file at any time. The final version is downloadable without the watermark. For further details go to www.thenbs.com/domestic externallink.

Paper version:
The hardcopy version of NBS Domestic Specification is the simplest of the NBS specification products. It consists of loose leaf sheets within a folder, the whole being a 'pack'. NBS Domestic Specification packs are bought individually, each pack being used for a single project. Sheets are folded A3, and are generally either 'work section' sheets (used for the actual specification), summary sheets related to the specification, or guidance sheets for the specifier.

Each work section sheet contains a specification covering workmanship and product standards for a particular range of work within a single trade, together with a work schedule, to be completed by hand, used to specify particular products and their properties. Each work schedule is split into subsections that deal with specific aspects of the work. The completed work schedules can be photocopied and issued to a builder for pricing.

The work sections each consolidate a number of NBS Building MW work sections, in order to permit specification of building elements. Sections cover everything from 'Demolition and site clearance' through to 'Communications and security systems', but only in relation to very straightforward, and essentially traditional, methods for construction, extension or maintenance at the domestic level.

Certain features are common to both the paper and the online version:
Preliminaries are minimal, since it is assumed that work will be of very limited extent and duration, and not comparable with those of other NBS products, but it is suggested that use is appropriate with either variant of the JCT Homeowner form of contract, and is also feasible with either variant of JCT or SBCC MW.

NBS Domestic is intended only for specification of work at the domestic level and may be used for new build, extensions, alterations and maintenance.

NBS Building, Minor Works:

NBS Building MW is used to create a set of preliminaries and a specification. If there is a need to price elements of construction (floors, walls etc.) then a separate bill of quantities or schedule of works must be created (usually using a word processing or spreadsheet programme). Preliminaries included relate largely to minor works forms of contract (JCT, SBCC, ICE etc.).

Clauses duplicated by the user in the software version are freely editable.

Use of NBS Building MW is largely a subtractive process. When starting work on a section the full content appears on screen. Editing consists of marking for deletion clauses not required in the completed specification, completing all inserts in clauses to be retained, and duplicating and amending any clauses requiring alteration. Since all clauses must be either rejected, accepted, or altered and accepted, this format provides an automatic checklist that helps the user ensure full coverage for the specification.

NBS Building MW is intended primarily for specification of work at the level of domestic, small residential or small scale commercial, and may be used for new build and extensions. A limited amount of content for refurbishment work is included but 'spot items', e.g. descriptions for alteration works, are generally covered in an added bill of quantities or schedule of work.

For details of the work sections and forms of contract covered by NBS Building MW see the Scope And Contents.

NBS Scheduler:

NBS Scheduler generates a complete three part document including preliminaries, a reference specification and a priceable schedule of work. Note that the reference specification (automatically produced to back up the schedule) is a non-editable document unless exported from NBS Scheduler.

Preliminaries are provided, generated by a separate software module, for a range of forms of contract at both minor works and intermediate level. Some, e.g. the SBCC Measured Term Contract and the GC Works/7 Measured Term Contract, are not available for other NBS specification products.

The content of the NBS work item libraries, once copied into a schedule of work, is freely editable.

Unlike other NBS specification products, creation of a document using NBS Scheduler is an additive rather than subtractive process. A new document starts with a blank screen or a 'template' (a system of headings and subheadings used to give structure to the schedule of works). Content must be identified in the NBS content libraries (or previously completed schedules) and dragged and dropped into the schedule of work before editing. This is advantageous in that it allows a simple document to be produced quickly, especially if the user has created a pre-edited set of commonly used constructions, but has the disadvantage that the specifier needs a very clear mental picture of the work required.

NBS Scheduler is capable of being used to specify a wide variety of work to most types of domestic, residential, small commercial and light industrial property, and may be used for new build, extensions, alterations and refurbishment.

For details of the work sections and forms of contract covered by NBS Scheduler see the Product area.

Last word

The initial question was "which version of NBS should I use to specify a building I am designing"?

The answer is "It depends".

Each of the four 'small works' NBS specification products have content that may be used for specification at the domestic level, and both NBS Building MW and NBS Scheduler have content that may be used for other building types. However there are a number of other factors to take into account and there can be no clear cut response to the question without these matters being considered too.

In terms of product complexity (low to high) the ranking for new users is probably:

  • NBS Domestic (paper)
  • NBS Domestic online
  • NBS Building MW
  • NBS Scheduler

If available the simplest product that meets the needs of the project should be used.

About this article

These are the personal views of Andrew Wilson, NBS Technical Author.