Types of Temporary Works Design Checks
In the world of construction, the importance of temporary works cannot be overstated. These are the structures and systems required to support the permanent works during construction. From scaffolding and formwork to shoring and propping, temporary works can represent a significant part of the construction process and have a significant impact on cost, time, quality, and safety. However, despite their temporary nature, these structures demand rigorous checks and oversite to prevent accidents and ensure compliance with safety regulations.
The following design check categories are what designs must adhere too in the UK.
Category 0 – Restricted for Standard Solutions
Category 0 covers temporary works that cover standard solutions where the basic design work has already been undertaken.
Examples include:
- Simple propping schemes, which require 1 or 2 props less than 1.2m high.
- Shallow excavations and pits not exceeding 1.2m deep/high using proprietary systems.
Category 1 – Standard Designs
Category 1 covers temporary works more complex than category 0, such designs would be undertaken using simple methods of analysis and be in accordance with relevant standards and suppliers literature. Checks and signoffs for these can be carried out by a member of the same temporary works design team.
Examples of these may include:
- Hoarding.
- Site cabins foundations.
Category 2 – Complex Designs
Category 2 covers complex designs, where checks include designs where a substantial degree of interpretation of structural information is required before the commencement of design. The checks and signoffs of these designs would need to be undertaken by a separate senior member of another design team.
Examples of these may include:
- Excavations support using sheet pile.
- Needling of structures greater than 2 storey’s high.
- Designs where stability is obtained by restraints at the top of the temporary works.
- Designed scaffolds and loading platforms which follows TG20 Design Guide.
- Temporary roof structures of all types.
Category 3 – Critical and Innovative Designs
Category 3 covers complex, critical and innovative designs, which result in complex sequences of moving and/or construction of either the temporary or permanent works. These designs include unusual designs or where significant departures from standards, novel methods of analysis or considerable exercise of engineering judgement are involved. One organization will undertake the original design brief.
There is then a separate design check undertaken by another organization for the same brief. Design check certificates and structural calculations are required to be submitted by both sets of structural engineers for these types of checks.
These may include:
- Temporary works combining interacting or multiple design.
- Partial demolition or modifications of existing structures.
- Large basements excavation and propping schemes.
- Complex and bespoke façade retention.
- Underpinning (foundation, basis, support).
Temporary works are an integral part of any construction project, providing the necessary support to build permanent structures safely and efficiently. Design categories 0-3 for design check in temporary works, offer a clear framework for assessing the complexity and risks associated with these temporary structures, guiding the level of design check required.
Back to all news