Environmental Advantages of Precast Products
Off-site fabrication of precast concrete cladding offers many efficiencies and advantages over traditional methods, which benefit the environment:
- Panels are manufactured concurrently with site preparation. This can reduce project construction times and the impact on the local community by over 50% (source: www.buildingforafuture.co.uk).
- As much of the work is performed in the factory, panels benefit from manufacturing efficiencies, innovations and design flexibility.
- Work on a construction site is hazardous. Off-site manufacturing allows work to be carried out in a controlled, comfortable and safe environment where safety requirements are much easier met and policed. Working in this environment improves quality, thus reducing defects and wastage.
- Materials and labour can be sourced locally, thus reducing transport emissions and supporting regional economies.
- Materials can be stored in safer conditions in a factory than on site, thus greatly reducing the risks of pollution.
- As panels are delivered without packaging and there are no site offcuts, off-site construction generates up to 90% less waste (source: WRAP – Waste & Resource Action Programme). Any waste that we do produce is easier to segregate for recycling and collection.
- With large panels, crane time and the numbers of lifts are optimized, thus reducing energy consumption.
- Off-site manufacturing uses less water than on-site – and especially in the case of Techrete as we recycle approx. 65% of water used in our Irish factory.
- In general, off-site manufacturing leads to a reduction in the number of deliveries to a site compared with traditional construction methods.
- Panels can be designed to be manufactured, transported and installed easily.
- Deliveries to site can be co-ordinated to minimize emissions and traffic disruptions.
- All panels are 100% recyclable at the end-of-life stage.
Getting it right from the start
It’s important, of course, to think long-term about sustainability in buildings, but this raises practical challenges. Indeed, the early stages of a building project can be particularly fraught or problematic. However, decisions made at this time can affect not only the build programme, but also long-term building performance, so it is essential to get them right.
Teams trying to address sustainability from the outset, therefore, need help to ensure that their decisions and subsequent actions produce the intended results. The early appointment of a precast cladding manufacturer can pay dividends because they will bring expertise, experience and insight to the process. In practical terms, project teams will often need to liaise closely with precast cladding manufacturers to ensure that sustainability objectives are met in the long term.
This involvement should start early in the design process, but to be truly effective it must continue throughout the detailed design, production information and construction processes.
Techrete offers the full suite of services, from design to manufacture and erection. That means that, from the outset, we can work closely with our clients to ensure optimal results.
Sourcing materials responsibly
In 2013 Techrete was awarded a ‘Very Good’ rating under BES 6001 – Responsible Sourcing of Construction Products (see on the Green Book Live – the independent reference source and online listing of environmental products and services).
Supply chain management
Through our Quality Management System, certified to ISO 9001, we have a documented system for our purchasing process and approval of suppliers.
We maintain a list of suppliers and ensure they have the necessary controls, processes and management systems in place to allow for the identification and traceability of supplier materials.
We minimize the impact of the transportation of our products by maximizing the load to capacity ratio for each delivery, thus reducing the number of trucks on the road.
We expect our suppliers and subcontractors to safeguard the health, safety and welfare of employees and any others who may be affected by their activities.
We ensure that our sourcing operations comply with our business codes of conduct and legal requirements through our integrated environmental and energy management systems. And we encourage local procurement of materials and labour.
Ethical policy, quality management and local investment
Techrete abides by its Ethical Policy Statement, its Worksafe Policy Statement, and its Smoke-Free Policy Statement.
Our Quality Management System records all training and qualifications received by our staff and subcontractors, and identifies opportunities for further training.
We invest in our local community. For example, we have donated to primary schools, a football team, a gardening association and a local scout group. We are corporate members of the Lion’s Club.
Techrete’s sustainable production
The manufacture of precast concrete cladding takes place in Techrete’s safe, efficient and well-managed factories. The protected environment in these facilities not only ensures high-quality products; it also makes environmental protection and sustainable manufacture easier to achieve.
Extensive use of quality management standards and procedures ensures that high standards are followed day in, day out.
Innovative approaches to conserve resources, prevent pollution and enhance safety
Materials and waste management
The way in which precast cladding is produced is inherently resource-efficient. In addition, the process relies on mainly local supply chains. Factory scheduling is highly efficient, with repetition being key to achieving the greatest economies.
Techrete has expertise in managing and conserving natural resources, taking great care to design concrete mixes so that cements, aggregates and other materials are combined to produce high-quality products. In addition, it seeks to reduce primary resource extraction, minimize waste and reduce production energy by using:
- Cement replacement materials – such as ground granulated blast furnace slag, fly ash and silica, which are by-products from other industries and would otherwise go to waste
- Self-compacting concrete – this removes the need for vibration – saving energy, reducing noise and preventing hand-arm vibration syndrome (HAVS) and hearing loss in workers – and uses less primary aggregates.
- Locally quarried stone – this saves transport emissions and fuel.
- Reconstructed stone – this uses small pieces of aggregate and stone that might otherwise be classified as waste and so saves tonnes of natural stone from being quarried.
- Computer-controlled batching and mixing of raw materials to avoid waste.
- Up to 100% recycled steel reinforcement – in fact, all Techrete’s steel rebar is composed of recycled steel, saving lots of energy and reducing waste. It can be cut and bent to shape on demand in the factory and is all purchased from CARES-approved suppliers (or similar approved standards).
- Recycled water from finishing processes – this reduces the burden on boreholes and mains water supplies; some factories also capture rainwater from their roofs.
- Timber sourced from Forestry Stewardship Council (FSC) approved suppliers for moulds and forms, and minimal use of hardwoods.
- Reusing moulds and tables – steel moulds can be reused many times and, if well-designed, timber moulds can be reused successfully.
- Recycling and waste minimization initiatives – segregation of waste happens at source.
- Zero packaging – precast products require no packaging for transport.
- Closed curing chambers and energy-efficient curing techniques.
- Sealed chambers for grit-blasting, producing virtually no waste as grit is recaptured and reused.
Over the past year, Techrete reduced its landfill waste, per tonne manufactured, by 28.8% in Ireland and 12.2% in the UK (13.3% in total).
Techrete’s waste reduction 2011–2013
Techrete has particularly focused on energy conservation and sustainability for several years.
In early 2010 Techrete appointed an Energy Management team to monitor and manage energy consumptions. In October 2010 we received IS EN 16001 (European Standard for Energy Management) certification and in September 2012, transitioned to the international standard ISO 50001. Since 2010 we have introduced numerous energy management and energy-efficient practices in our factories.
Staff awareness and induction programmes have been run to instil in staff the importance of viewing sustainability as integral to all Techrete operations. In addition to weekly reports to senior management, KPIs are posted on staff noticeboards. Online sub-meters show energy consumption in real time and allow us to identify and respond to any issues as soon as they arise.
We have worked with the Sustainable Energy Authority of Ireland, the Carbon Trust UK and energy consultants to carry out product Life Cycle Assessments and identify all areas of our operation we could improve on from an energy efficiency point of view.
The initiatives implemented reduced overall energy consumption, per unit manufactured, by more than 13% in three years.
Reduction in energy usage
Our move to a greenfield site in Balbriggan, Co. Dublin in 2008 allowed us to design a factory with energy efficiency in mind. The improvement here has been dramatic – a 40% reduction in energy consumed per unit output over the past three years.
40% reduction in energy usage, Balbriggan, 2009–2012
Our factory in Brigg, North Lincolnshire posed a different challenge as much of the work involved retrofitting an older factory. However, we achieved a 7.5% reduction in KWh consumption per unit output in 2010. Severe winters in 2011 and 2012 in the north of England greatly increased our gas consumption as aggregates and sands froze in our silos. We have since insulated all our silos, which should ensure a drop in gas consumption.
In addition to reducing energy consumption, Techrete has been investigating green energy sources to replace existing ones and, using 2008-2009 as a base year, has targeted a 35% reduction in C02 emissions per unit output by 2020.
The initiatives introduced to date have achieved that target some seven years early. Techrete’s CO2 emissions per unit output have fallen by 38% over the past three years.
CO2 emissions reduced by 38% in just three years
In our Dublin office, geothermal energy is used for heating and cooling through an exposed flooring system using cast-iron piping. Exposed concrete surfaces maximize the thermal capacity of the office. Passive ventilation in lieu of air conditioning and PIR-controlled lighting help to reduce energy consumption.
The insulated concrete panels used in the construction of the facility were designed with a large thermal mass within the insulated portion of the building. As the concrete absorbs energy when surrounding temperatures are higher than the mass and gives back energy when the surroundings are cooler, this flattens out daily fluctuations in temperature, improving comfort levels and reducing energy requirements.
Analysis of energy consumption and statistics from the Sustainable Energy Authority of Ireland and the Carbon Trust show that energy consumption in our office is some 70% below levels required in a typical office. The panels used in the construction of our offices were designed and manufactured by Techrete.
Dublin has seen the CO2 produced per unit output fall by over 60% over three years. For the reasons mentioned earlier, our Brigg factory has seen a slight increase. Our aim is to hit the 35% reduction target for our factories both cumulatively and individually.
CO2 emissions reduction at Balbriggan
Over 65% of water used in Balbriggan is recycled water
Techrete consumes a large amount of water in the manufacture of precast panels. The water is used not just in mixing the concrete but also in washing, polishing and acid etching panels.
Water and waste concrete produced by our Balbriggan factory are passed through our modern recycling plant where waste water is separated from aggregates, treated and pumped back into our factory to be reused. The separated aggregates can be recycled and used as hardcore.
Techrete’s Balbriggan plant was designed and built so as to maximize our ability to recycle and reuse water. All rainwater is drained from hard surfaces to our 2,500m3 attenuation pond where it can be treated and used in our manufacturing process. Over 65% of water now used in Balbriggan is recycled water.
We do not have the same recycling facility in Brigg but have reduced water consumption there by just over 7% over the past two years while our volume of output increased by 22%, reflecting a 25% reduction in water consumed per unit output. We are currently investigating the drilling of boreholes at our Brigg factory which would reduce our consumption of potable water even further.
Techrete wins Energy Management Award
Our work in energy and emissions reductions saw Techrete win the Sustainable Energy Authority of Ireland (SEAI) SME Energy Management Award in 2012, presented by Dr Brian Motherway, CEO of SEAI, and Minister for Communications, Energy & Natural Resources Pat Rabbitte. This award recognized the manner in which Techrete has embraced energy management, incorporated it in the day-to-day running of its business, and has involved employees in supporting effective energy efficiency initiatives. It also recognizes the reductions in energy usage and CO2 emissions achieved.
Techrete wins Green SME Award
In April 2013 Techrete was presented with the prestigious Green SME Award by Environment Minister Phil Hogan. The Green Awards, now in their fifth year, reward companies that strive to help prevent climate change by reducing waste, carbon emissions and water consumption.
Transport policy drives multiple benefits
Techrete uses just-in-time deliveries and GPS tracking on trailers to avoid unnecessary traffic congestion. With deliveries booked in at the construction site and communication between the wagon driver and Techrete installation teams, this allows the wagon to be met and offloaded as it arrives on site.
We have invested in new Tech Trailers, which allow the transport of larger panels and reduce the number of loads needed for a job. These larger panels also reduce the number of crane lifts needed, speed up the erection process and minimize traffic disturbances in the local area.
Weekly monitoring of load-to-capacity statistics for each job allows us to set traffic reduction targets. Our Transport Policy sets a target of 90% load-to-capacity ratio. In 2013 we achieved an overall ratio of 90.2% (90.6% from our UK factory and 89.5% from our Irish factory).
In line with our Green Travel Policy Statement, Techrete promotes green travel initiatives, reduces travel through video conferencing and restricts emissions from company cars.
Installation – energy-efficient, less expensive, simple, safe
The energy used during the construction of a building can easily be overlooked. After all, most of a building’s energy is consumed during its operation. However, with energy prices rising steadily, there is growing pressure to ensure sustainability in onsite operations.
Precast cladding panels can be produced with all the necessary elements of wall construction included. For example, internal and external finishes, insulation and fully-glazed windows can all be fitted in Techrete’s factory – no need for anything else to happen on site apart from jointing and sealing. This is a highly cost-efficient way of facing a building: it is fast, uses virtually no labour, requires minimal equipment and produces no waste. All of this benefits the contractor in developing and implementing a Site Waste Management Plan.
The installation process is also energy-efficient. With precast cladding:
- Crane time and number of lifts are optimized, so electrical energy use is reduced.
- Site cranes are used, so there’s no need to bring in additional specialist equipment.
- There is no need to double-handle the panels.
- There are no wet trades.
- Little energy is needed and power tools are not required.
- Small teams of specialist erection workers travel to site together, saving on fuel emissions.
Sustainable performance in use
Concerning the sustainability of buildings, the most important aspect is its performance during its life. This encompasses energy use, water consumption, maintenance cycles, fitness for purpose, fire safety, etc. It is crucial to design sustainable buildings with their whole life performance in mind. Buildings should be robust, energy-efficient, healthy and comfortable for their occupants, whether for commercial, domestic or industrial uses.
So that buildings can offer outstanding performance standards in use and even outlast their intended service life, they should be long-lasting and adaptable to change. In this regard, our precast panels offer a number of benefits:
- Where desirable, our concrete cladding panels can be removed safely (deconstructed) and reinstalled after works to extend the footprint of a building. This is very resource-efficient and reduces unnecessary waste from refurbishment projects.
- The high-quality surface finishes achieved in our factory result in precast panels with extremely robust face to the weather for many decades, even hundreds of years. They are therefore easy to maintain.
- The typical 50+ years’ design life reduces the frequency of maintenance cycles and also lessens costs and inconvenience for the owner.
- Precast concrete increases in strength for many years after it is cast, but even immediately after installation it is durable and robust and resists rain penetration, wind-blown debris and, in some cases, blasts and chemical attack.
- Precast concrete cladding does not catch fire, burn, melt or drop molten particles and can prevent the spread of fire – usually only minor repairs are required to make good after a fire.
Research shows that concrete buildings can pay back their initial carbon ‘investment’ in just over 10 years, and then continue to provide savings by having an in-built ability to moderate extremes of temperature, particularly during the summer. Essentially, the use of precast concrete cladding in a building contributes to its thermal mass, which helps to even out daily and seasonal temperature swings, making indoor spaces more comfortable without having to resort to air-conditioning. This saves energy and money in the long term and, in the short term, saves on capital investment and maintenance bills for air-conditioning plant.
However, in countries with a lengthy winter season, such as the UK and Ireland, certain levels of insulation must also be provided in the building envelope to ensure that heat is not lost through the façade. There is no problem in combining precast concrete cladding with insulation products either in the factory or on site.
Efficient insulation solution
Precast concrete insulated sandwich cladding panels offer a very efficient and practical solution, achieving a U value of 0.25 W/m2K or better. Insulation sits within two precast concrete layers; the external leaf provides protection against the elements and the internal layer provides thermal mass ‘in the right place’, i.e. facing internal heat sources such as people and computers.
The vulnerable insulation layer is thus protected effectively and the building envelope is doing all that can be asked of it by moderating extremes, whether these arise from cold winter temperatures or internal heat gains. The occupants remain comfortable and the building owner saves energy and money.
What’s more, precast concrete is inert, so it doesn’t give off any gases, toxic compounds or volatile organic compounds in use.