Concrete Compass: Offsite concrete construction
Navigating to useful resources and guidance
The use of precast concrete elements is a well-established construction method. Concrete offsite solutions range from whole building and structural systems, to precast construction components, offering numerous benefits during construction and over the whole life of a building. Many of the resources related to concrete on this website are applicable to concrete offsite solutions. This compass aims to help navigate towards some of the latest information and resources, including guidance documents and case studies, that can assist in making informed design decisions related to an offsite concrete solution.
- Offsite Concrete Construction is a free-to-download publication which includes guidance and benefits of using offsite concrete construction and delves into details of some of the more common techniques. This 24-page guide is a great starting point for those wanting a comprehensive overview of design considerations.
- Residential Cellular Concrete Buildings technical guide, includes detailed ‘How-To’ guidance on construction systems, including crosswall, tunnelform and twin wall.
- Concrete Offsite Solutions on-demand webinar This webinar explains the range of offsite solutions available in concrete and their benefits, along with design guidance for their use.
- Modern Methods of Construction (MMC) – a collection of solutions available using concrete.
Additional resources related to specific aspects of offsite concrete are available here, including technical articles in Concrete Quarterly magazine and on-demand webinars. For a list and links to case studies of projects using offsite concrete solutions search the case studies webpage using the pre-defined filters ‘precast cladding’; ‘MMC/Structural precast’ and ‘hybrid concrete construction’.
Precast concrete cladding offers opportunities to create high quality facades requiring little maintenance. It provides a weatherproof envelope, while fulfilling architectural, structural and other requirements in terms of fire resistance, thermal performance and sound insulation. A summary of the benefits of precast concrete cladding and further information can be found here.
Crosswall construction is a modern and effective method of construction that employs factory-produced, precision engineered, concrete components. Being concrete, the structural elements are durable, non-combustible and virtually maintenance free, having little impact from the effects of water.
These are all benefits available during construction but also over the life of the building. The concrete offers excellent acoustic performance, security, airtightness and thermal mass.
The system uses precast concrete floors and load-bearing walls ideal for buildings of a cellular nature, for example hotels, student and secure accommodation and apartments.
More information can be found in the Offsite Concrete Construction publication. For case studies utilising crosswall construction use the keyword ‘crosswall’ in a search on the case studies web page.
The current drive for factory production and modern methods of construction (MMC) has led to increased use of precast systems that can be used to construct both high- and low-rise housing quickly and efficiently.
Offsite Housing Solutions: Technical article in Concrete Quarterly, Autumn 2019. Includes case studies on Lansdowne, Birmingham; Aston Place, Birmingham; Victory Plaza, London as well as new innovations under development.
Tall Construction: Powered by Precast. Article in Offsite Magazine (issue 22) discusses the benefits of building tall using concrete offsite solutions, which include fire resistance, thermal mass and vibration criteria. Read more.
See also guidance on crosswall construction – a well established structural solutions for residential development, particularly student and secure accommodation and apartments.
Hybrid concrete construction (HCC) can deliver very significant cost savings, enhanced buildability and all of the other advantages of off-site construction, improving both speed of construction and safety. Solutions may include a combination of precast and insitu components used in a building (such as cast insitu frame and precast concrete cladding), but there are also hybrid structural solutions that combine precast concrete cast insitu into a structural element. These examples include twinwall and omnia deck.
Further guidance is provided here.
There are many ways in which precast concrete can be used to provide sustainability credentials to a development including local and responsible sourcing, material efficiency, durability and thermal mass as well as resilience to fire and flood. A summary of the sustainability benefits of precast concrete features in the Offsite Concrete Construction guide, published in 2019.
Since publication there has also been significant progress in the measurement reporting and reduction in the embodied carbon of concrete, including precast concrete elements. And while reuse and repurposing of existing precast structures is becoming more common place, projects and solutions are also beginning to emerge demonstrating opportunities for precast concrete to be designed for disassembly and reuse.
- Material efficiency in manufacture and construction helps lower the embodied carbon of concrete offsite solutions. Structures designed using hollowcore floors, for example, utilise both pre-stressing and void formers in manufacture and have been demonstrated to offer some of the lowest carbon options through analysis in Concept v4.
- Offsite solutions in concrete are often manufactured to suit project specific criteria, which can include project specific sustainability performance from responsible sourcing, to cutting carbon. For more information see Specifying Sustainable Concrete, published in 2020.
- Generic Environmental Product Declarations (EPDs) for a number of precast concrete products have been developed, in accordance with BS EN 15804: 2012 +A1 (2013), by MPA Precast and updates are on going.
- In addition MPA Precast have been assisting precast member manufacturers with the production of their own verified product EPDs by producing a life cycle assessment tool and training to members. The tool, developed with sustainability consultants, Thinkstep, has an extensive list of over 50 material inputs covering all the commonly-used aggregates, cements, reinforcements and admixtures.
- The precast concrete used in the UK is predominantly manufactured in the UK with distances for architectural and structural precast averaging around 124 km in the latest report.
- The UK precast concrete industry gathers and reports sustainability credentials annually as part of the industry's Sustainability Charter.
Codes and Standards
The structural design of offsite concrete construction is to Eurocode 2 (BS EN 1992-1-1) but there are further codes for precast concrete elements. The general code for all precast concrete elements is BS EN 13369 and a list of codes for specific elements, with summary descriptions, can be found here.
UK Precast Concrete
- MPA Precast is the trade association for the UK precast concrete sector. As an industry body it operates a number of specialist product groups as well as sector schemes for health and safety, and sustainability.
MPA Precast Architectural and Structural Group provides expertise and experience in offsite construction with resources on structure and facades including test reports and codes. Also available are newsletters on a vast range of construction sectors and precast concrete applications, including cladding and its use of digitalisation, such as BIM. More information.
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