Specification for construction
Specifications describe the products, materials, and work required by a construction contract. They do not include cost, quantity, or drawn information, and so need to be read alongside other information such as quantities, schedules, and drawings.
Specifications vary considerably depending on the stage to which the design has been developed, ranging from performance specifications (open specifications) that require further design work to be carried out, to prescriptive specifications (closed specifications) where the design is already complete.
Having a prescriptive specification when a contract is tendered gives the client more certainty about the end product, whereas a performance specification gives suppliers more scope to innovate and adopt cost-effective methods of work, potentially offering better value for money.
Typically, performance specifications are written on projects that are straight-forward and are well-known building types. For more information, see Performance specification.
Whereas prescriptive specifications are written for more complex buildings. For more information see: Prescriptive specifications.
They can also be used in combination. Items crucial to the design may be specified prescriptively (such as external cladding) whilst less critical items may be specified only by performance (such as service lifts).
Key to deciding whether to specify a building component prescriptively or not, is considering who is most likely to achieve best value, the client, the designers or the contractor:
- Large clients may be able to procure certain products at competitive rates themselves (for example the government).
- Some designers may have particular experience of using a specific product (although some clients may not allow designers to specify particular products as they believe it restricts competition and innovation and may relieve the contractor of their liability for 'fitness for purpose').
- The contractor may be best placed to specify products that affect buildability.
Specifications should be developed alongside the design, increasing in level of detail as the design progresses.They should not be left until the preparation of production information. By tender, they should describe every aspect of the building in such a way that there is no uncertainty about what the contractor is pricing.
Aspects of the works are generally specified by:
- Products (by standard, a description of attributes, naming (perhaps allowing equivalent alternatives) or by nominating suppliers).
- Workmanship (by compliance with manufacturers requirements, reference to a code of practice or standards, or by approval of samples or by testing).
It should be possible to verify standards of products and workmanship by testing, inspection, mock-ups and samples, and documentation such as manufacturer's certificates.
Specifications should be structured according to work packages mirroring the separation of the works into sub-contracts. This makes it easier for the contractor to price and so may result in a more accurate tender. A standard classification system should be followed, such as Uniclass.
[edit] Related articles
- Bill of quantities BOQ
- Construction Specifications Canada CSC.
- Construction Specifications Institute CSI.
- Final specifications.
- MasterFormat.
- NBS Chorus.
- NBS Source.
- Performance specification.
- Prescriptive specification.
- Specification guidance for construction
- Tender documentation for construction projects
- Schedule of work for construction
- Technical specification
- Outline specification
- Output-based specification.
- Green Guide to Specification.
- Schedule
- Common Arrangement of Work Sections.
About the wiki
Anyone is welcome to use and contribute to the wiki in different ways.
[edit] Engaging with the wiki
You can:
- Contribute to existing articles
- Create articles
- Share articles through social media and other channels
- Contact the CIRCuIT project to let us know what you think and how we can improve
[edit] Add your own content
To contribute to or create an article, you can follow these steps:
- Register as a user
- Read through the editorial policy and guidance on writing and contributing to articles
- See the detailed help page on tips on writing wiki articles
- Try editing a test article
- If editing an article, select 'Edit this article' underneath the article title
- If creating a new article, select 'Create an article'. In the 'Select categories' area, expand the 'Industry context' list and tag 'Circular economy' to add your article to this wiki
[edit] Who is this wiki for?
The articles contain information on implementing circular economy approaches in construction that could be relevant to:
- Architects
- Construction contractors
- Designers
- Developers, owners, investors
- Engineers
- Landowners
- Manufacturers and supplier
- Universities and research
- Urban planners
[edit] About CIRCuIT
The Circular Economy wiki is supported by the Circular Construction in Regenerative Cities (CIRCuIT) project, which is funded by the European Union's Horizon 2020 research and innovation programme. CIRCuIT is a collaborative project involving 31 ambitious partners across the entire built environment chain in Copenhagen, Hamburg, Helsinki Region and Greater London. Through a series of demonstrations, case studies, events and dissemination activities, the project will showcase how circular construction practices can be scaled and replicated across Europe to enable sustainable building in cities and the transition to a circular economy on a wider scale.
Comments
For your country please check examples from major builders they normally have detailed examples that can be modified to suit for build.