Thermal Breaks

Addressing climate injustice with smarter building design

Climate change continues to be one of the most pressing issues of our day and all industries are going to need to make significant changes to challenge the irreparable damage to our world that could continue to be caused.

However, there is a strong argument that it is those in more developed countries should be working hardest in order to dramatically reduce the impact they are currently having and look to undo as much of the damage already done.

As a result, a historic deal has been struck at the COP27 summit that will see ‘richer nations’ pay ‘poorer countries’ for the damage and economic losses caused by climate change.

Climate injustice around the world

Nearly three-quarters of all excess emissions come from the US and the EU alone. The US is responsible for 40% of all excess emissions with the EU slightly behind on 29%. Latin America, Africa, the Middle East, and Asia combined are only responsible for 8% of excess emissions, and yet these are often the geographic regions that are feeling the repercussions of climate change the most. (Source: The Structural Engineer August 2022)

The most recent example of this is the deadly floods in Pakistan. Pakistan is reported to have received more than 3 times its usual rainfall in August, making it the wettest August since 1961. These floods have destroyed 1.7 million homes, and nearly 1500 people lost their lives. Whilst the region has been subject to monsoons before, studies have shown that climate change could have increased the most intense rainfall over a short period in the worst-affected areas by about 50%.

This region being so significantly negatively impacted by the effects of climate change despite contributing so comparatively little is the very definition of climate injustice.

A change in approach to building design to reduce climate injustice

When looking at the fastest-growing economies in the world, they are mainly developing nations such as India, Bangladesh, and Rwanda. However, when you look at some of the biggest construction projects in the world, 7 out of 10 of the largest construction projects in the world being started, worked on, or completed in 2022 are in developed countries.

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The European construction sector is expected to grow by 2.5% in the same period.
As the built environment continues to grow in the developed world, the construction industry needs to create effective collaborations between architects, contractors, developers, and project stakeholders in order that buildings are designed with environmental factors in mind.

Insulation

Through the cost-of-living crisis partially caused by the issues in Russia and Ukraine, there are many easy-to-access statistics on how much insulation can save you in terms of money spent on energy bills – the Environmental Protection Agency in the US state that the average homeowner can save 11% of total energy costs by adding insulation.

The cost of bills might be a driving factor for individuals but the reduction in the use of energy means fewer carbon emissions which can only have a positive impact on the environment and decrease the need for reparations in the future.

The phrase ‘insulation’ make bring to mind domestic solutions such as cavity wall and loft insulation but in fact, when done efficiently, insulating buildings starts at the building design stage with the choice of building materials and steps taken throughout to reduce the transference of heat/cold between inside and outside.

In addition to the building materials selected for walls and the types of windows and doors specified, it has long been recognised that thermal bridges within building envelopes can cause problems of heat loss, leading to poor energy performance.

The use of structural thermal breaks between steel and concrete protruding through building envelopes will ensure efficiency in this area. This also includes finer structural details such as façade system supports, balcony attachments, data centre substructures, and rooftop plant installations.

Sustainable building materials

According to the November 2020 National Infrastructure Strategy in the UK, there are six overarching recommendations where the action taken now will result in rapid decarbonisation of the construction sector. One is that current design and performance standards should be updated to enable more holistic design approaches that support the efficient design and reuse of materials.

This was echoed in a report by the Royal Academy of Engineering on ‘Decarbonising Construction’, which stated that using sustainable materials as standard and low-carbon procurement were two key vital aspects in achieving net-zero transformation in the construction sector.

Current end-of-life scenarios for three of the most common construction materials; concrete, timber, and steel are shown below.

Whilst steel production is currently a source of greenhouse gas emissions, a revolution in steel production is within reach by reusing or recycling it as standard. Reusing it lends itself to modular design where old materials can be made into aspects of a new building, which would also use less energy than recycling it.

The downcycling of concrete – crushing and using it in different applications – is a common practice in the construction sector. Currently, aggregate made from downcycled concrete accounts for 6% to 8% of aggregate use in Europe. Maintaining and expanding this practice could prevent concrete from going into landfill, but doesn’t influence the emissions from cement production since it meets the demand for a different application.

Overall reusable materials such as steel are ideally placed for reducing emissions, and use of steel is on the rise. In 2021 the use of structural steelwork in industrial buildings increased by 16.4% and by 10% for offices with further growth predicted, showing an appetite for steel as a sustainable and reusable material.

Combining insulation with sustainable building specification

Where sustainable and environmentally friendly building design collaborations will be most likely to succeed is with a smarter design made up of energy efficiency, reusable material specification, and an approach to insulation that goes beyond what is the bare minimum.

This is key for buildings designed for developed countries, but ‘the West’ can also lend their skills and technology – and provide education – to construction in developing countries in order that they can get commercial structures and residential developments right first time.

This will ensure they avoid a future situation that countries like the UK find themselves in currently, where they are looking at millions of buildings dating back to before the industrial revolution that need retrofitting with insulation to meet the ideal standards that could be achieved with the initiative and funding.

Summary

Engineers, architects, and specifiers are facing a huge challenge in taking a holistic approach to sustainability to help tackle climate change and tackle climate inequality that is plaguing the world.

This isn’t something to worry about in the future. With developing countries already feeling the force of environmental change and lives already being lost, climate inequality caused by construction needs our full attention now before the effects are made worse and spread further still across the world.

About the author

Chris Lister BA(Hons) DipArch – Commercial Manager Structural Thermal Breaks

Chris Lister is the Commercial Manager for Farrat Structural Thermal Breaks and the Northern Region Chair of the British Construction Steel Association BCSA.

Having studied both Engineering and Architecture he has worked exclusively in the construction and building product design sector. Chris heads the development of Farrat Structural Thermal Break products and Facade Design Solutions.

He is a passionate contributor to the global discussion on fire safety in high-rise structures and building physics research. An advocate for achieving the highest level of energy efficiency Chris is the Farrat Lead on our new product development Project “Falcon” aiming to design out bouncy balconies

Thermal break materials with Farrat

Farrat’s Structural Thermal Breaks are an essential component for energy-efficient buildings. If you would like to learn more about the integration of thermal breaks in structural connections, contact our Structural Thermal Break team by email, call us at 0161 924 1600 or fill in the contact us form.

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Chris Lister Farrat

Mixing timeless architecture and energy efficiency with fire rated structural thermal break material Farrat TBF

22 Ropemaker is set to be a brand-new comprehensive development in London, made up of over 420,000 sq ft spread over 27 stories. Within close proximity to several of the key London Underground stations, this commercial building has been designed with well-connected and forward-thinking businesses in mind. As a result of this, sustainability and energy efficiency are driving factors in material-specifying decisions

The challenge

The rise in energy costs across the UK means that energy efficiency is a growing and more pressing consideration for businesses looking for new premises.

In addition to the cost of gas and electricity bills, energy efficiency is important to businesses looking to ensure they are minimising their carbon footprint wherever possible and to be able to demonstrate that.

The number of outside spaces including balconies and roof terraces, as well as the creative use of façades in the classic design of this building, meant that to maximise energy efficiency without compromising on structural integrity Structural Thermal Breaks would need to be used across the entirety of the façade at multiple structural connection scenarios

Another key challenge in any high-rise building development is fire safety. Since the Grenfell disaster where 72 people died and another 70 people were injured when a 24-story block of flats burnt down, the use of fire-safe materials has been at the front of both residents’ and developers’ minds – especially in high-rise buildings – as has the new legislations being rolled out across England and Wales.

Challenge our engineers to ensure the efficiency and safety of your projects. Email us or call +44 161 924 1600 to talk to the team.

The recently enacted Building Safety Act 2022 has been created to address an identified lack of oversight, as well as to clarify the roles and responsibilities within the construction and maintenance of ‘high-risk development’ (buildings that are at least eighteen metres tall or at least seven floors, containing two or more dwellings.)

The level of accountability and scrutiny that this act drives further increases the focus on and demand for fire-resistant materials wherever possible.

The solution

Farrat TBF was the fire-rated structural thermal break material selected by façade specialists Josef Gartner GmbH to prevent heat transfer through beams where the external building aspects meet the interior.

Farrat TBF is an A2,s1,d0 rated non-combustible structural thermal break material that can maintain optimal structural performance at temperatures at 550°C and maintain integrity beyond 1000°C In addition to being the leading fire-rated thermal break solutions; exceeding all current fire regulatory requirements for buildings above (and below) 18m, Farrat TBF also provides high-level thermal performance to solve structural thermal bridge issues.

The outcome

“High-rise building design that takes into account both energy efficiency and fire safety is set to be the norm in cities around the world, but is especially poignant in London,” states Chris Lister, Commercial Manager of Structural Thermal Breaks at Farrat.

“To see Farrat TBF being used in a building designed to ensure the comfort and safety of those occupying it as well as such as a strong focus on wellbeing with the use of outside space is hugely rewarding.”

Fire-rated thermal break materials with Farrat

Farrat’s Structural Thermal Breaks are an essential component for energy-efficient buildings. If you would like to learn more about the integration of thermal breaks in structural connections, contact our Structural Thermal Break team by email, call us on 0161 924 1600 or fill in the contact us form below.

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Farrat Launch Europe’s first CE marked Structural Thermal Break Plates

Following extensive research and development work, alongside the European Office of Technical Approvals EOTA, Farrat is proud to have produced Europe’s first European Assessment Document for structural thermal break plates.

This has now led to the issue of European Technical Assessment 22/0333 for their Farrat TBK and Farrat TBL Structural Thermal Break products, specifically for European partners, projects and customers.

European designers and fabricators are now able to specify CE-marked products, compliant with all aspects of EU regulation supported by the appropriate legally required Declarations of Performance

Copies of the ETA are available for download in German, Dutch, French, and Spanish via the Farrat website. Corresponding Declarations of Performance DoP are available on request with all orders.

This award further strengthens the independent assessment and certification already held by Farrat, building on our long-standing BBA Certification 17/5435 as well as being part of the BRE certified thermal details scheme and TBK’s Passive house certified component status.

Farrat’s A2, s1,d0 non-combustible Farrat TBF material is due to be added to the new ETA at the start of 2023.

Farrat Structural Thermal Breaks can be used in all external to internal Steel to Steel and Steel to concrete connections to reduce energy loss and avoid the issues associated with thermal bridging and condensation.

Full details of how and where Farrat Structural Thermal breaks improve connection performance can be found in our Farrat Technical Guide.

Structural Thermal Breaks Connections

Challenge our engineers to ensure the efficiency and safety of your projects. Email us or call +44 161 924 1600 to talk to the team.

Farrat’s Structural Thermal Breaks are an essential component for energy-efficient buildings. If you would like to learn more about the integration of thermal breaks in structural connections, contact our Structural Thermal Break team by email, call us on 0161 924 1600 or fill in the contact us form below.

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Get in touch

    The Building Safety Act 2022: A new framework for ‘higher risk buildings’

    The Building Safety Act 2022 is a significant overhaul of the regulatory framework in England and Wales regarding how all buildings are to be designed and constructed, and how higher-risk buildings, specifically high-rise and multiple occupation buildings, are to be managed. The Act enacts the recommendations of the UK Government’s review of the 2017 Grenfell Tower tragedy. It received Royal Assent in April this year and is expected to be rolled out in stages over an 18-month period.

    The Act has been created to address what has been identified as a lack of regulatory oversight, as well as establish clarity on roles and responsibilities in the construction and maintenance of this kind of development. As the different stages of this act are rolled out in the coming year or two, everyone involved in these projects – architects, structural engineers, developers, contractors, and consultants – need to take note of how they will be affected.

    Key aspects of The Building Safety Act 2022

    This document is over 250 pages long and will need expert inspection, but here are some of what we consider to be the key themes within the act.

    Rigorous Accountability

    A new Building Safety Regulator has been created – under the jurisdiction of the Health and Safety Executive – and they will be responsible for overseeing improvements in the safety of all buildings in general, but most specifically they will be taking charge of enforcing more rigorous management in the building and management of higher-risk buildings.

    In a move that relates most closely to the events surrounding the Grenfell Tower tragedy, for all higher-risk buildings there should be an identifiable ‘accountable person’, responsible for ensuring that fire and structural safety is efficiently and properly managed in the building. This accountable person is responsible for assessing the structure and external walls – this includes elements such as balconies, facades, and entrances/exits – and ensuring that general fire precautions are taken to ensure those areas are safe.

    A higher-risk building in England and Wales is defined as buildings that are at least eighteen metres tall or at least seven floors, containing two or more Dwellings. In Wales, there are proposals for an even more stringent definition, applying to any building with two or more dwellings regardless of height Scottish Legislation has already gone further with the new Scottish Building Standards prohibiting the use of combustible materials for building envelopes above 11m.

    Fire safety has always been important, but never before has there been such a high level of accountability for those responsible for both designing and building developments, and also managing their operation.

    building safety act 2022

    Get in touch: Challenge our engineers to ensure the efficiency and safety of your projects. Email us or call +44 161 924 1600 to talk to the team.

    More Scrutiny and Regulation

    When being built, every development has been subject to the need to meet regulations, but now there will be a series of ‘gateways’ surrounding planning, as work begins, and on completion. These new gateways are designed to boost HSE regulation and ensure that enough scrutiny is given at every stage and not just at the start and/or end.

    In addition to this, a ‘New Homes Ombudsman’ scheme has been created to give owners of new build homes the opportunity to seek redress against developers and builders and enable social housing complainants to escalate any related complaints following the usual landlord’s complaints process. This scheme puts more scrutiny on developers and builders as well as landlords, with a more direct route for any perceived shortcomings to be raised and addressed.

    Rights to Remediation and Damages

    The biggest financial implication long term is the increase in the rights of inhabitants to remediation and damages.

    For the first time in building regulations, many qualifying leaseholders are protected under new laws – regardless of when buildings were purchased or built – from bearing the costs of some remediation and building safety work on their building. This means when it comes to work such as replacing flammable materials, the liability is usually on a building’s developers.

    For new homes, warranties are to be provided by developers that last 15 years. The new act will also enable individuals to claim damages where they suffer harm because work on a building has not met Building Regulations standards, and this limitation period is also 15 years.

    Fire resistant materials and the Building Act 2022

    With this update to building regulations deriving specifically from a fire as catastrophic as the Grenfell Tower fire, it was always inevitable that the focus was going to be on fire safety and holding those in charge of designing, building, and managing high-risk buildings such as tower blocks accountable for the safety of the inhabitants.

    The new level of accountability, scrutiny, and potential damages as well as a moral obligation to protect human life drives increased demand for fire-resistant materials wherever possible, and not just when it’s meeting the bare minimum to pass regulations.

    The use of tested fire-resistant materials means that fires that break out can be contained to the smallest possible area – known as a fire compartment. However, walls, ceilings, floors, and doors within this fire compartment need to be able to withstand being exposed to a fully developed fire on one side while not transporting heat.

    The highest level of fire resistance in materials is Class A and within that, there are two subcategories. A1 materials are totally non-combustible while A2 materials have ‘very limited combustibility’. A1 materials have no contribution to fire, and A2 materials have limited contribution to fire.

    Building Safety Act 2022 fire resistant materials

    Extremely stringent tests must be passed in order for construction products to reach a Class A rating and specifying a material that reaches this level is one of the best ways in material specification to demonstrate responsibility in design, building, and managing fire safety within a building, as well as protecting the inhabitants of said building.

    Fire resistant Structural Thermal Breaks

    Having launched the world’s first A2-rated Structural Thermal Break, Farrat has continued to review and improve the performance criteria for this material –
    Farrat TBF – to meet and exceed the stringent structural requirements of two hours at 550⁰C fire resistance.

    After it was independently A2,s1,d0 tested and certified to EN13501-1, we carried out exploratory testing in conjunction with an intumescent coating manufacturer. Our results show that Farrat TBF not only performs well as part of a coated connection but is also able to withstand temperatures in its own right in excess of 1000⁰C for 2 hours while maintaining a structural compression performance. See the full data on these tests.

    Farrat TBF fire test

    Contact us now for an initial consultation by email, on +44 161 924 1600, or fill in our contact form below.

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    About the author

    Chris Lister BA(Hons) DipArch – Commercial Manager Structural Thermal Breaks

    Chris Lister is the Commercial Manager for Farrat Structural Thermal Breaks and Northern Region Chair of the British Construction Steel Association BCSA.

    Having studied both Engineering and Architecture he has worked exclusively in the construction and building product design sector. Chris heads the development of Farrat Structural Thermal Break products and Facade Design Solutions.

    He is a passionate contributor to the global discussion on fire safety in high-rise structures and building physics research. An advocate for achieving the highest level of energy efficiency Chris is the Farrat Lead on our new product development Project “Falcon” aiming to design out bouncy balconies

    Chris Lister Farrat

    Contact us now for an initial consultation by email or on +44 161 924 1600, or fill in our contact form below.

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      Using Thermal Imaging when retrofitting existing buildings to be energy efficient

      There is growing awareness across the UK and Europe on the number of abandoned buildings currently empty when there is such a high demand for residential properties. In the UK more than 700,000 homes lay vacant, with 1.8 million in Germany, 2 million in both France and Italy, and 3.4 million in Spain. With some businesses downsizing their offices as post-pandemic attitudes to work cause a shift to hybrid and home working, there is potential to repurpose this disused space to tackle the home shortage across the continent as high rises and offices in the world’s capitals sit empty.

      In order to do this successfully older buildings will need – at a minimum – to be brought up to standard when it comes to energy efficiency and insulation. However, as concern about both energy bills and climate change grows, developers should be looking to go beyond the standard to ensure that homes are affordable to live in and limit impact on the environment.

      Understanding the actual performance of existing buildings is key to being able to design retrofit solutions and optimise the use of materials in the new build. One method of understanding performance levels in real time is using thermography

      Thermal Imaging

      Thermal imaging can be used when looking to develop existing buildings, to see where heat is ‘escaping’ and so where thermal insulation should be retrofitted with insulating materials. This might include well-known standard forms of insulation such as cavity wall insulation or loft insulation, but also other key areas where additions are being made to the building such as new external envelopes or exiting features and listed facades being retained and supported by new internal structures. This is also the case for new features such as balconies or plants requiring structural penetrations through to the main building frame

      Thermal bridge at windows, doors and roof

      Using thermal imaging technology to measure how the building is performing in terms of insulation now, takes the guess work out of thermal modelling – predicting how it will perform in terms on insulation in the future without any additional insulation or with the insulation planned.

      Farrat thermal breaks thermal image

      Why is retrofitting so important?

      The government in the UK has been widely criticised for lack of action in retrofitting existing buildings with insulation, with a focus on energy efficiency for new buildings.

      However, building designers and investors are seeing that in order to repurpose or develop these buildings into ones that people want to buy or rent, they need to be affordable to live in. Energy prices are one of the people’s leading concerns for both now and the future.

      A survey conducted by YouGov in the Czech Republic, Germany, Italy, and Spain found extensive public support for new regulations to increase energy savings in homes, stating they wanted to buy and rent energy-efficient homes. A quarter of UK households are looking at improving the efficiency of their homes in response to the surging cost of energy bills. Energy efficiency is of genuine importance, especially across the EU.

      Summary

      Developing abandoned buildings and repurposing buildings no longer in demand is a sound environmentally friendly measure when creating new domestic and commercial properties by using brownfield sites and reusing existing structures and materials.

      However, it is only by using technology such as thermal imaging to measure energy efficiency and understand what’s really going on under the skin of these homes and commercial buildings that will maximise their positive impact on reducing energy usage and minimising their carbon footprint.

      Sustainable design

      On a mission to ensure energy efficiency in building developments

      Whether you’re redeveloping or repurposing existing buildings, Farrat Structural Thermal Breaks are an essential component for any energy-efficient building. For more information on integrating thermal break solutions into structural connections, visit our Structural Thermal Break hub or one of our dedicated portals:

      Architects Portal

      Structural Engineers Portal

      Buyers Portal

      #onamission

      As UK cost-of-living concerns soar, is energy efficient building design a key aspect in easing the burden?

      When the Office of National Statistics recently updated its Opinions and Lifestyle survey through to mid-February, over three-quarters of adults reported that their cost of living had increased – up 14% from November 2021.

      Alongside the cost of food, 77% stated that this was due to an increase in gas or electricity bills, and whilst half of these people were looking to tackle this by cutting back on non-essentials, 35% of people were actively looking to cut the amount of electricity and gas they are using and 31% were driven to cutting back on spending in food and essentials.

      Government action in energy efficiency

      At the start of 2021, the UK’s Housing Minister announced that all new homes must be more energy-efficient and “zero-carbon ready” by 2025, and a consultation on higher performance targets for non-domestic buildings with the objective of them to be zero-carbon within the same time scale.

      However, when this proposal was at the planning stage, campaigners in this area warned that this would mask the actual energy efficiency itself and that whilst this might make the building look like it is performing better, the reality is it could be worse.

      This month the government has also stated that whilst they are looking at launching a boiler upgrade scheme and investing in helping to stimulate the production of ‘British heat pumps’ which can reduce demand for gas, they will not ‘impose’ measures to improve energy efficiency in existing homes. RIBA president Simon Allford said the government ‘must realise that we will not ease the burden on vulnerable households unless we improve the energy efficiency.’

      Building designers, engineers and specifiers looking to go beyond the recommended standards

      Whatever the minimum requirements are, the great news is that building designers, structural engineers, and specifiers are looking to exceed regulating body expectations and go beyond the recommended standards both for new builds and retrofitting older buildings.

      In addition to the construction industry’s ethical commitment to reducing the amount of energy needed to power homes and businesses, the significant increase of the energy price cap, the associated jump in household bills, and the threat of further increases in autumn, are driving energy efficiency to the front of both buyers’ and renters’ minds.

      New research carried out by the Home Builders Federation has shown that being ‘eco-friendly’ and ‘having a good Energy Performance Certificate’ were rated as the second and third most important factors respectively, beaten only by having ‘private outdoor space’.

      Nearly three quarters of respondents stated that they are worried about the energy performance of their current home, and nearly a quarter said that energy efficiency will be a ‘crucial’ factor in their next home move.

      In short, if building designers and developers want to future proof their investment and attract buyers or renters, being able to demonstrate energy efficient that doesn’t just meet legislations, but also reduces the current cost of living could be essential.

      Energy efficient building design

      The role of Structural Thermal Breaks in energy efficiency

      Structural Thermal Breaks are widely considered to be the most efficient way to thermally separate structural connections and prevent heat loss in the building envelope. This includes external to internal structural connections, façade system connections, structural columns and exoskeleton structures, linear steel and masonry connections, roof penetrations, and concrete frame to steel connections.

      With the increase in demand for private outside space, growing demand for Structural Thermal Breaks is in preventing thermal bridging where balconies are installed.

      When using Structural Thermal Breaks with thermal efficiency credentials such as BRE (Building Research Establishment) and Passive House, alongside a generally proactive approach to insulation, this can ensure a significantly higher level of energy efficiency, without compromising structural integrity.

      Thermal Bridging Model

      Summary

      Building designers, engineers, and specifiers are facing a huge challenge in taking a holistic approach to energy efficiency to help tackle climate change, but also reduce the impact of the growing cost of living due to energy prices.

      For more information on integrating thermal break solutions into structural connections as part of an energy efficiency strategy, visit our Structural Thermal Break hub or one of our dedicated portals:

      Architects Portal

      Structural Engineers Portal

      Buyers Portal

      Upcoming Webinar: The significance of Structural Thermal Breaks in high rise fire design and Building energy performance

      Farrat is partnering with the Institute of Structural Engineers this June to produce a new webinar on the significance of Structural Thermal Breaks in high rise fire design and building energy performance. This webinar is ideal for designers, architects, engineers, and specifiers, who are looking to go beyond the standard in fire design and energy efficiency.

      Since the tragic circumstances of the Grenfell disaster, designing for fire construction material choice in all its facets has become a focus of design teams across the world. In balance, the global demand for energy efficiency and net-zero carbon pulls designers in an equally important direction.

      This webinar with Farrat looks through the lens of Structural Thermal Breaks at the multi-role demands of building components to deliver best-in-class performance in sustainable credentials and building physics without compromising on fire safety.

      The webinar will assist designers in understanding:

      • The latest developments in UK Fire and Building Safety regulations
      • Current requirements for specifying safety-critical building products
      • Up to date thought on the UK standards for construction material performance information
      • Current direction and time frame for Structural ‘Green’ Steel and the journey towards Net Zero
      high rise fire design

      Date: Tuesday 21st June

      Time: 9 – 10am BST

      Presenter: Chris Lister. Commercial Manager – Structural Thermal Breaks

      Chris Lister is the Commercial Manager for Farrat Structural Thermal Breaks and British Construction Steel Association BCSA National Council Member. Having studied both Engineering and Architecture he has worked exclusively in the construction and building product design sector, in both senior technical and commercial roles.

      At Farrat he is principal in the development of Farrat Structural Thermal Break products and facade design solutions. He’s a passionate contributor to the global discussion on fire safety in high-rise structures and building physics research and advocate for achieving the highest level of energy efficiency in building design.

      Chris is a dedicated father, diehard Rugby player, and fair-weather motorcyclist.

      The top 5 questions asked by engineers when specifying structural thermal breaks

      The ability to transmit structural loads whilst addressing thermal performance through a building envelope has long been a difficult balance for building designers. The weight of decision has often fallen on the side of the structure, with the importance of structural integrity winning out against the impact of structural members piercing the thermal envelope.

      However, as the energy demands of new and retrofit buildings have grown, so have the requirements to minimise that energy usage and the potential of issues such as thermal bridging.

      This has resulted in greater levels of insulation in planar elements of a building envelope, leading to more noticeable and detrimental effects of those ‘hard to treat’ details such as structural penetrations. Add to this the need to achieve compliant critical internal temperature factors for the avoidance of unsightly or harmful mould growth and mitigating thermal bridges in a building envelope moves higher up the list of problems to solve.

      Equally, the growing influence of fire design on structures has also led to the requirement for enhanced performance criteria of building materials in relation to fire that are incorporated into the building envelope. To address this imbalance, new building materials and methods of thermally breaking structural connections, such as steel beams and balcony connections, have been developed.

      In the below guide, we address the most frequent questions asked by Structural Engineers when specifying Farrat Structural Thermal Breaks.

      1. Which Farrat Structural Thermal Break material should I specify?

      Farrat Structural Thermal Breaks take the form of flat plates of any dimensions, which provide Architects with complete design freedom and Structural Engineers the capability to design to standard codes, with a simple configuration.

      Farrat offer three independently tested Structural Thermal Break materials, which are designed to balance high structural performance and low thermal conductivity:

      1. Farrat TBK (Yellow) is most specified across typical connection details, with high compressive strength (312MPa fck) and the best thermal performance in the range (0.187 W/mK).
      2. Farrat TBF (silver) is the optimum material when fire performance is a consideration, such as within high-rise buildings, due to its high compressive strength (355MPa fck) and low thermal conductivity (0.2 W/mK) performance characteristics, supported by an A2, s1,d0 Non-Combustible Classification.
      3. Farrat TBL (Black) is the favourable material when structural loadings and requirements for thermal performance are lower, and budgets are constrained, offering medium compressive strength (89MPa fck) and thermal conductivity (0.292 W/mK) performance characteristics.

      2. How do I design connections incorporating Farrat Structural Thermal Breaks?

      A breakdown of what to consider when designing structural steel connections is contained within the Farrat Structural Thermal Break Technical Guide and supporting SCI, Steel Construction Institute assessment document.

      As an overview:

      1.  Structural Thermal Break plates should be considered as a “pack” in terms of connection design.
      2. All Shear forces need to be accommodated by the connection bolts. As a result of the multiple layers in the connection the grip length of the bolts may be significantly increased, it may also be necessary to reduce the anticipated shear resistance of the bolts in the connection.
      3. Reference should be made to BS EN 1993-3 1-8: 2005 Eurocode 3. Design of steel structures.

      Example screenshots adjacent are taken from the Farrat extension for Tekla Structures that creates Farrat Structural Thermal Break connection plates. The component automatically takes the plate dimensions and holes of the plate it is fixing to.

      3. Can Farrat Structural Thermal Breaks support the loads I am designing for?

      The exact physical and mechanical properties for Farrat Structural Thermal Breaks are contained in the Farrat Structural Thermal Break Technical Guide.

      As a quick guide:

      1. Farrat TBF and Farrat TBK materials offer compressive strength comparable with Steel.
      2. Farrat TBL has a compressive strength greater than Concrete.
      3. Structural Thermal Break plates in a connection should only be designed to resist compressive forces.
      4. Consideration should also be taken of compressive creep. Farrat materials are formulated to resist long term creep, but this element should be factored into any design.
      5. Many materials which exhibit good thermal properties have poor long term creep profiles.
      6. Reference should be made to BS EN 1993-3 1-8: 2005 Eurocode 3. Design of steel structures.

      4. What is the friction coefficient for Farrat Structural Thermal Breaks?

      The coefficient of friction of a thermal break plate is not a relevant property for the structural design of connections with non-pre-loaded bolts.

      Whilst figures for frictional resistance of Farrat Structural Thermal Breaks can be obtained, it will differ depending on the material with which it is in contact and should be treated with caution when designing connections involving Preloaded or TCB bolts.

      5. Will Farrat Structural Thermal Break plates achieve a 120-minute fire rating?

      Structural steel connections that require a 120-minute fire rating will typically need to be protected with either an intumescent coating system or a fire protection board. In all situations, the Structural Thermal Breaks should receive the same level of protection as the steel.

      However, Farrat TBF Structural Thermal Breaks have been tested unprotected in fire conditions, in structural steel connections, to temperatures more than 1000°C for 120 minutes and maintained structural integrity.

      Different building types and legislators have differing technical and regulatory requirements for fire design, but if fire is a concern that requires addressing, then the use of non-combustible thermal breaks is one way to mitigate that risk.

      Farrat TBF fire test
      Farrat TBF fire test

      In summary, when designing for Structural Thermal Breaks:

      1. Check that the chosen material is independently verified to resist the applied compression forces, with an appropriate safety factor applied to determine design loading.
      2. Check that any additional rotation due to compression of the thermal break plate is acceptable.
      3. Check the shear resistance of the bolts is acceptable given that there may be a reduction due to the use of packs and larger grip lengths.

      If using Pre tensioned bolts:

      1. Check the slip resistance of the connection considering the coefficient of friction and the number of surfaces.
      2. Check the thermal break plate can resist the local compression forces around the bolts.

      Where fire performance is concerned:

      1.  Consult with Farrat for the correct specification of fully tested and certified materials.

       


       

      For more information on integrating thermal break solutions into typical, or bespoke, structural steel connections, visit our Structural Thermal Break hub or one of our dedicated portals:

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      Project Showcase – Structural Thermal Breaks for energy efficiency and fire safety

      Over the last few months, we have witnessed a growing public interest in energy efficiency in parallel to increasing numbers of building designers who are looking to go beyond the standard when it comes to insulating building connections in a wide range of building types. As a result, we remain busy with a large number of Structural Thermal Breaks projects as we head into Q2. Take a look at a few of our most recent thermal bridging projects below.

      Primark Belfast, Northern Ireland

      The Primark store in Belfast was previously based in the Bank Building in central Belfast, however, it was tragically destroyed in a fire in 2018, with firefighters taking 4 days to totally extinguish the flames.

      The COVID19 outbreak also meant significant delays to the starting of the rebuild and renovation of the building, but now works are well and truly underway. Fire safety is a priority for the redevelopment project, alongside structural integrity and retrofitting the historic Grade B1-listed five-story building with modern insulation.

      Farrat A2 fire- Structural Thermal Break material Farrat TBF has been selected for use across the project, to provide premium-grade protection against thermal bridging, with non-combustible properties.

      Primark Belfast

      Hockliffe Road Care Home, Leighton Buzzard, England

      Hockliffe Road Care Home

      Fire safety is often a key concern when looking to house those who would find evacuation in the instance of a fire a challenge.

      Hockliffe Road Care Home is currently being constructed on the site of a former police station, and will deliver a modern 63-bedrooms development built to the highest sustainable standards using Passivhaus criteria.

      The scheme will also integrate Farrat TBF Structural thermal breaks, as Passivhaus certified building components.

      Golden Jubilee Hospital Clydebank, Scotland

      The three-story expansion of the NHS Golden Jubilee in Clydebank, Scotland, is set to include theatre suites, orthopaedic facilities, outpatient and pre-operative spaces, a surgical admissions and recovery unit, a new endoscopy unity, and a sterilising and processing department.

      Farrat is working with developers on the dramatic entrance steelwork, ensuring that structural thermal bridges are eradicated to enable the hospital to maintain its high energy efficiency.

      Projections involving steel, including balconies, outside shelters, façades, and entrance features, create additional challenges when it comes to ensuring cold external temperatures do not affect the environment inside, and using Farrat Structural Thermal Breaks in this growing health facility will do that.

      Energy efficiency in modern building design

      Energy efficiency is front and centre in the news at the moment, with increasing utility bills creating a major concern for both individuals and businesses. Building designers are now looking to go beyond following the mandatory regulatory requirements and future proof the use of the buildings at an affordable rate.

      Golden Jubilee Hospital Clydebank, Scotland

      Whether buildings are using the increasingly specified steel structure or using concrete, Farrat Structural Thermal Breaks are an essential component for any energy-efficient building.

      For more information on integrating thermal break solutions into structural connections, visit our Structural Thermal Break hub or one of our dedicated portals:

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      The top 5 questions asked by architects when specifying structural thermal breaks

      The ability to transmit structural loads whilst addressing thermal performance through a building envelope has long been a difficult balance for building designers. The weight of decision has often fallen on the side of the structure, with the importance of structural integrity winning out against the impact of structural members piercing the thermal envelope.

      However, as the energy demands of new and retrofit buildings have grown, so have the requirements to minimise that energy usage and the potential of issues such as thermal bridging.

      This has resulted in greater levels of insulation in planar elements of a building envelope, leading to more noticeable and detrimental effects of those ‘hard to treat’ details such as structural penetrations. Add to this the need to achieve compliant critical internal temperature factors for the avoidance of unsightly or harmful mould growth and mitigating thermal bridges in a building envelope moves higher up the list of problems to solve.

      Equally, the growing influence of fire design on structures has also led to the requirement for enhanced performance criteria of building materials in relation to fire that are incorporated into the building envelope. To address this imbalance, new building materials and methods of thermally breaking structural connections, such as steel beams and balcony connections, have been developed.

      In the below guide, we address the most frequent questions asked by Architects and Building Envelope specialists when specifying Farrat Structural Thermal Breaks.

      1. Which Farrat Structural Thermal Break material should I specify?

      Farrat Structural Thermal Breaks take the form of flat plates of any dimensions, which provide Architects with complete design freedom and Structural Engineers the capability to design to standard codes, with a simple configuration.

      Farrat offer three independently tested Structural Thermal Break materials, which are designed to balance high structural performance and low thermal conductivity:

      1. Farrat TBK is most specified across typical connection details, with high compressive strength (312MPa fck) and the best thermal performance in the range (0.187 W/mK).
      2. Farrat TBF is the optimum material when fire performance is a consideration, such as within high-rise buildings, due to its high compressive strength (355MPa fck) and low thermal conductivity (0.2 W/mK) performance characteristics, supported by an A2, s1,d0 Non-Combustible Classification.
      3. Farrat TBL is the favourable material when structural loadings and requirements for thermal performance are lower, and budgets are constrained, offering medium compressive strength (89MPa fck) and thermal conductivity (0.292 W/mK) performance characteristics.

       

       

      2. What thickness of thermal break should I specify?

      Farrat Structural Thermal Breaks come in a range of thicknesses from 5mm t0 25mm. The only way to accurately calculate the thickness of a structural thermal break is to carry out finite element analysis on the connection and its allied components. This is not common practice due to the relative rarity of details requiring Structural Thermal Breaks and the time and cost of carrying out the thermal modeling.

      However, it is possible to understand from a typical example the effects of thickness of plates on example connection.

      Farrat illustrates this for their products using BRE (Building Research Establishment) certified thermal models, which show that despite achieving a lower thermal performance than the surrounding building fabric, it is possible to remove the negative effects of a cold bridge with a minimal amount of insulating material (typically a 15mm -25mm thickness). Plates may be used in multiples, but 25mm will mitigate most thermal bridge issues for dwellings and commercial office building details.

      3. Do Structural Thermal Breaks need to be as thick as the surrounding wall insulation?

      The primary determinate for the thickness of a Structural Thermal Break is its effect in achieving a satisfactory critical internal temperature factor on the warm side of the structural connection. It is not necessary for the Structural Thermal Break thickness to match the surrounding wall insulation thickness to be a success.

      Since the thermal break is required to be a structural element, it will always be a relative weak point as an insulant.

      However, as illustrated in Farrat’s latest Passive House Certified Details, this still makes it possible to achieve the highest of building performance standards.

      4. Will the Structural Thermal Break meet my U value requirements?

      U value calculations are the simple method of understanding the thermal performance of a build-up of construction materials in a flat plane (planar). Structural Thermal Breaks are typically used to solve problems in ‘point’ structural connections or in some case linear connections. As such their performance cannot be calculated using the U value method of calculation and require a Psi or Chi value calculations to be undertaken.

      These calculations can only be undertaken using 2D or 3D finite Element Analysis (FEA) modelling.

      As this is currently not common practice, Farrat utilise their typical BRE Certified Thermal Models, to provide indicative Psi and Chi values for common structural connections to allow simplified specification of structural thermal breaks where calculation models have not been created.

       

       

      5. Do Structural Thermal Breaks need to be Non-combustible?

      The use of non-combustible materials, particularly in high-rise buildings has become more commonplace in recent years due, in part, to high-profile building fires and subsequent investigations.

      Structural Thermal Breaks are extensively used as part of the structural support in façade systems or as the main structural connection in balconies. These elements are key to the performance of the building envelope in the case of fire and the avoidance of catastrophic failure and collapse.

      Farrat TBF is an A2,s1,d0 non-combustible Structural Thermal Break material that is capable of withstanding 1000°C heat and maintains its structural integrity in the event of a fire.

      Different building types and legislators have differing technical and regulatory requirements for fire design, but if fire is a concern that requires addressing, then the use of non-combustible thermal breaks is one way to mitigate that risk.

      Farrat TBF

      For more information on integrating thermal break solutions into typical, or bespoke, structural steel connections, visit our Structural Thermal Break hub or one of our dedicated portals:

       

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