Modern Methods of Construction

Modern Methods of buildingThis dissertation provide discuss the effect of Modern Methods of Construction (MMC) and particularly the Off-Site Construction (OSC), on the structure welkin today, and how these methods will contribute to help and resolve social, financial, and environmental difficulties that facing the UK.1.2 DEFINITIONOff-site formulation is an application of modern methods of reflexion MMC where kink sector meets the industrial sector, or by other word, a fusion between grammatical twirl and manufacturing. Off-site winding is where tot all(prenominal)y of building comp 1nts, or even a whole building, manufactured in factories away from the actual site where the building will be sited, or simply is where the aspect site is unlike from the building site.1.3 TERMINOLOGYOff-site face has variant terms, terms like (pre prevarication, off-site assembly, factory assembly, pre-assembly, off-site manufacture, etc.). The term off-site saying is generally use nowad ays to any part of the bodily structure care for that takes place in factories.1.3 HISTORYOff-site construction is not vernal, in the 20th century specifically in the post war clipping, off-site construction (that quantify the term use probably was factory assembly or prefabrication construction) were needed to replace rapidly buildings which were destroyed or damaged during the war, But due to the lack of technology and modern end product proficiencys, development in climb downweights, high- forte materials, and new modern methods of construction that today is available, it gained unfortunately negative signifi ordurece.The time of the wheelbarrow is completed, announced Jean Prouv in 1947, echoing Le Corbusier.We need usines maisons, homes produced in the factoriesSince then, a further sixty years live passed the manufacturing sedulousness has come with story of success of the mechanization, has enhanced electronics and grafting. Today industrial automation and manufac tures from shoes to personal computers, and from planes to crackers, all now machine-made, in Seattle as a small village in China.The building construction is still the same. With genuinely few exceptions, the building remains largely an object made by make with tralatitiousistic techniques. And the only construction industry still relies to logical and largely pre-industrial processes. With known effects low productivity, forecast time and cost much much random, exposed to all levels of quality and possibilities and approximations of production conditions argon vary widely, backward technologies and unskilled work.1.4 OVERVIEWWhy choose off-site construction now? What is so different from the traditional way of construction? Why is sustainability constantly creation brought up? Before I examine these points, I have to mention some of the essence(p) facts that have already occurred. Since the beginning of the century, it is increasingly being talked about and discussed, the world and its temper changing. United Nations ask for action on it. The world met in a summit in Copenhagen to discuss how they jakes resolve the raising temperature that might cause damages and risks to the global, and how to lower expertness and CO2 emission. Why I menti adeptd climate change and we be talking about off-site construction? The answer is surprisingly, buildings are responsible for about one third of global energy inhalation and if we add the energy use for construction the amount dismiss easily be append to the half(a). All of this means that we need to build truly economic houses and in an efficient way, and thats arouse be achievable only by off-site construction.There is a severe accommodation deficit in the UK. The g everyplacenment has announced plans for the construction of 200,000 new houses per year, but that target has never achieved yet. Off-site construction do-nothing help the accommodation industry to achieve that target where riotous d elivery is needed. Speedier delivery in construction is one of the say-so vantages of off-site construction and search showed that it can reduce the time of construction process to the half because it takes place in a desirable condition away from the unpredictable weather that can affect and delay the process on-site. And research showed that it can reduce the time of construction process to the half because it takes place in a desirable condition away from the unpredictable weather, factory built accommodation. Offsite construction already features in the production of social accommodation.Skill shortages in the UK construction industry are a severe problem. In 2001 the UK construction industry estimated it needed to instill an extra 74,000 skilled workers every year for five years just to make up for the shortages of bricklayers, plumbers and electricians (Verbus System, 2006).In 2009, the chartered institute of building (CIOB) concluded a third research on skill shortages, an d the result again showed that the construction industry is still suffering a skills shortage, which is likely to continue to be a challenge for the building sector. Off-site construction can play an important role to resolve this extend. The research showed, compared to much than traditional techniques, off-site construction can reduce on-site labour requirements to less than a quarter. This result achieved from some work took place off-site. Off-site work involves different labour that is not to a lower place pressure as the on-site workforce. Off-site construction and modern methods of construction (MMC) can on that pointfore make better use of scarce labour.1.5 DISSERTATION constructionThe dissertation consists of an introduction chapter, tercet main chapters and conclusion chapter Chapter two discuss the advantages of off-site construction for the building sector, club, and the environment. The chapter also will discuss the conditions in parade to gain the full advanta ges of off-site construction. Chapter three explain the flakes and forms of off-site construction, and where off-site construction takes place in the building and in the construction process. Off-site construction takes place in different areas of the building, so how off-site construction will incorporate with the mainstream construction process. Chapter four show and examine some of off-site construction grammatical case studies and in which type of building it takes place.CHAPTER TWO ADVANTAGES OF OFF-SITE CONSTRUCTION2.1 INTRODUCTIONOff-site construction, as I mentioned, is part of modern methods of construction (MMC) and is referred to as any of the components of the building built in a high quality take careled factories where they use advanced techniques to manufacture highly specialised doors, windows, stairs, wall panels, frame structure, and have it away volumetric pods and then transport them to the location where it will be utilize and to be assembled on-site.Off-s ite construction has many advantages that are why nowadays thither are more companies and contractors using this method rather than the traditional way of construction, even governments make more pressure to use this method to speed up housing delivery.Modern methods of construction can provide good quality homes with less on-site labour, in a shorter time, with at least the same building performance and at similar cost when compared to more established techniques.Off-site manufacturing and partnering processes increasingly play a part in solving todays problem of touching towards a sustainable housing industry.The advantages of off-site construction can be classified into two types Business advantages, social environmental advantagesModern construction methods can produce important benefits for housing authorities and developers, not the least of which is the reduced emphasis on on-site activity. This is particularly important in a time of increasing demands on an already stretc hed labour force. As with any new way of doing things there are risks, but these can be mitigated by good go steady planning and management (Sir John Bourn, head of the National Audit Office, 2005).2.2 ADVANTAGESLess time in construction process, cost predictability, higher quality, support the society and the environment, resolving skilled labour shortage, reduce health safety risks, and helping the business the economy. These are key advantages of off-site construction.2.2.1 Reduced construction timeBusiness advantages give a huge encouragement to the contractors and designers to use more off-site construction components with their design and building processes. The greater speed of manufacturing and on-site compendium is an important factor for business gain. Earlier the delivery of the building means earlier the return of the investment. Modular construction for framework, that is an off-site construction, is up to 40-60% quicker than traditional building methods. The pre dictability of the delivery also is very important for the financial calculation of the business in terms of cost and revenue. The manufacturing process of the components in quality controlled factories is just about accurately estimated as well as the delivery to the site and the assembly operation.2.2.2 Cost PredictabilityCost-effectiveness is an important factor to show the difference between the off-site construction method and the conventional one. Approximately, around 80% of the construction cost are fixed inwardly the first 20% of the design process.The graph below highlights the potential for cost reduction and alternatively the resistance to the cost of change during the project life. As the project progresses, the opportunities for implementing variation or change reduce and the consequent costs associated with these variations inception substantially, Where off-site production techniques are to be used, these should be introduced archeozoic in the process.While off-s ite construction has tended in the past to be more expensive than brick block, now is being reduced to the same level due to the innovation of more techniques and to the variety of the components, and these bringing even greater economies.2.2.3 Superior prizeOff-site manufacture for building components significantly improves the quality and the efficiency of the building due to high standard of quality control and test.Buildings exceed requirements on sizeable and thermal insulation levels, so this means that are more sustainable.2.2.4 Help the society and the environmentOff-site construction has also can help the society and the environment. Millions of affordable homes are required to meet growing demand, and there is increasing pressure to further improve efficiency and sustainability performance during construction and throughout the animation of the buildings.Off-site construction is environmentally friendly if it is planned well from the early stages of design and by integ rating all the grant chain together. Less energy is generally required to develop the modules or off-site manufactured components. With improved process control ,buildings are pre-engineered each exactly the same and so can be adapted for ease of tiling and this should lead to reduced levels of cop on site of up to 70% and subsequent costs. In addition, with improved control of materials flow, raw materials can be recycled rather than skipped as often happens on site.The advantage of using OSC methods related to the reduction of waste to landfill are that the material exercising in the factory is reduced up to 90% by the careful design and procurement of materials, reducing the amount of waste generated both on-site and off-site.Offsite manufacturing was identify as a key potential method for promoting sustainability within the construction industry. Sustainability is increased as sound and thermal insulation is improved. Reduced time on site means less disruption to neighbouring residents or businesses.2.2.5 Reducing reliance on skilled labourWhile there is a significant shortage of housing in the UK, and the government plans to build more accommodation houses, there is another problem facing to achieve these plans as well the building industry a whole which is the skills shortages bricklayers, plumbers and electricians. Off-site construction helps to build more houses by reducing reliance on increasingly scarce skilled labour by reducing the number of labour where semi-skilled factory labour can be used during the construction of modules.2.2.6 Improve Health and safetyHealth and safety issue also give off-site construction an advantage, it has been proven to be a safer method of construction because there are fewer components involved than traditional methods and there is no need for high quantity of labour on-site for the assembly process.2.2.7 Business integration and economy developmentOff-site construction helps to integrate the supply chain. When exe cuted effectively, the off-site construction process involves key manufacturers and suppliers early in the feasibility and design stages of the project. This ensures that the specialist skills and knowledge of these key suppliers are embedded within the project and can influence the design and construction phases of the project. Where appropriate these key suppliers should be given ownership of the design and involved fully in the carrying into action of delivery, repositing and movements of materials and components.CHAPTER THREE OFF-SITE CONSTRUCTION WHERE IT TAKES PLACE?3.1 Forms of off-site constructionOff-site construction can take a number of forms. The form and terminus of acceptance within the projects will depend on the type of project Is there a large proportion of duplication or replication? for example in hotels and hostels, the type of client Is the client a one-off or repeat client?, and the relationships and the arrangements between the project members.Off-site buil dings and components systems range from small bolt-together sections to virtually fat buildings.Systems can be categorised as Sub-assemblies Frames Panels (open or closed) Volumetric system Hybrids system3.1.1 Sub-assembliesSub-assemblies are the most traditional and widely used system in off-site manufacturing which is being used for many generations. This type of off-site construction can include elements using different type of materials such as concrete beams, block floors, and foundations.Prefabricated foundation systems can consist of precast, post-tensioned, concrete beams.An additional examples for sub- assemblies systems are the glass reinforced plastic for chimneys, make for curtain walling, and timber stairs.3.1.2 FramesFramed structures, which are pre-assembled in factories, supply the structural support to buildings and are not something new feature in construction. Lightweight pre-assembled frames which can be delivered promptly to the site, speeding up the construct ion times for the main structural elements. The benefit of pre-assembled b put structures can help of reducing site cutting and the inaccuracies that can arise from it.An example of framed structure is the steel frame module. Steel works in off-site construction are taking the most important part of the factory controlled construction due to the characteristics of the steel itself that can be shaped and moulded in any form the result is light strong steel modules structures.The UK construction market is one of the most steel intensive in the world, with steel proving to be the material of choice for UK architects and structural engineers in the multi- history building market. The 2007 Market Shares Survey figures show steel construction consistently takes in excess of 70 per cent over double the market share compared to when the survey was first carried out in the early 1980s.(Housebuilder Developer. 2008).The Steel Construction impart has carried out a study of different construc tion projects using various levels of off-site steel construction technologies in bustling urban sites. The goal of the study was to recognize the benefits of off-site construction relating to the reduction of the disruption caused to local residents by the construction operations. The study also aimed to quantify these benefits in terms of the reduction in dust, noise, vehicle circulation and the impact of site-generated waste on the environment.3.1.3 PanelsPanels are two dimensional frames that contain both the structural and the infill element, are soused together on site. Example of panels is pre-assembled floor, wall, and roof panels. Using the right sealants are very important to gain the benefit of off-site manufactured panels in order to stand up the frames rapidly. The simplest form of off-site manufactured panel system is lightweight infill panels that are fixed to the structural frame, where the most complex form are the prefabricated sandwich panels which consist of bo th, the structural element, internal and external finishes.3.1.4 Volumetric SystemVolumetric system is the frame and panel systems, and when the building is assembled and built from a serial of volumetric steel or timber modules, connected together to form a room or groups of inhabit to form complete structure.Modular construction is also a term used to refer the volumetric assemblies.While the foundations are being prepared under factory conditions, the modules are manufactured and finished (or partially finished) off-site, under factory conditions, then transported to the building site and assembled and connected to the foundations, then added the exterior cladding and the roof.Modular construction is more sustainable than traditional techniques because of the minimum foundations that required and because it is built under factory conditions, the modules are in better quality and defects are minimized.Modular construction uses the same techniques from the industrial sector but t he result does not look like mass production product. Sophisticated modules and panels can be produced and can be easily customised by the clients requirements, and with new advanced techniques finishes cladding and roofing, give the building its natural skin that suites the surrounding.An example of volumetric module structure is bathroom pods. Bathroom pods are a very economically solution when it integrate with the whole construction process in large quantities such as student accommodations, hotels, hostels, hospitals, and prisons.Bathroom construction process can use Off-site construction technology, which in compare to the traditional way, would normally be carried out on-site. If we remove the construction process of the bathrooms to a controlled factory environment, bathrooms will become more ecological, functional, and with lower building costs. Bathrooms that we call them smart will also become more common with highly environmentally toilets and showers systems and with mo re advanced technology like tapes with sensors. The quality of bathrooms pods is far superior to the traditional on-site construction, more stylish, with high quality materials, and better for the environment in terms of a lower carbon footprint, lower levels of waste and reduced transportation of components.3.1.5 Hybrids SystemHybrid systems (often referred to as semi-volumetric) are a combination of all the other type, and this type where the flexibility of production and the varieties of consumer choice by combining the best features in a maven system play the important role of it.Plant rooms is an example of a hybrid volumetric module manufacturingPlant room is a room or space in a building sacred to the mechanical and electrical equipments and then they need an intensive labour. If plant rooms built off-site where there is cheaper labour, this can be more economically. Other advantage of plant rooms built in factory is if a project in time difficulties, always the installatio n of the services is squeezed, so using modular plant rooms certainly will help to avoid this problem.CHAPTER FOUR CASE STUDIES4.1 Case Study British Land ropemaker site, LondonRopemaker is a commercial building for British Land, one of the UKs largest Real Estate Investment Trust. It is built in an eminent site in London. The 21 storey and three basement levels has 55,000 square metres net lettable space. The high profile building has impressive green certifications achievement including a BREEAM excellent rating.The development has been realised using off-site construction technologies in a large number of parts in the building.This study aimed to evaluate two products manufactured off-site a modular walling system Podwall from Swift Horsman, and Technik storey system supplied by Grants LTD.The research aimed to compare in deep analysis off-site construction techniques products to the traditional way of construction in terms of waste on-site and off-site, resources needed on sit e, efficiency and productivity, cost, environmental impact analysis and end of life assessment, health and safety, and installation time.PODWALL research resultsPodwall saved approximately 40% to programme. Each floor at Ropemaker had an 11 week programme to install the Podwall (3 blocks per floor one ladies, one gentlemen and one disabled toilet), which would be equivalent to 15 weeks for traditional fit out.The waste on site is reduced because the Podwall is manufactured off-site. The result showed that the largest amount of waste generated is from the packaging, which is very important to protect the product on the delivery from between factory and site.Total waste produced is approximately 213m3 from Podwall washrooms. If we give the low levels of waste monitored during the process of the Podwall erection, traditional waste would considerably exceed that figure. In terms of waste recycling the percentage of materials recycled from Ropemaker exceeds 85%.The Podwall washroom pack age (54 toilet blocks), which is delivered over 1969m2, has a prize of approximately 6m. The main differences in cost, that the services are integrated off site into the walls and cubicles for the Podwall, bit in the traditional system the services installation and cubicles essential be installed on-site and the cost of the installation of these services on site is higher. The indirect costs in the traditional way do not run as the increased cost of waste and removal, and the increased programme time to install.TECHNIK research resultsIn terms of performance and time, Technik flooring system took168hrs per 100m2 for the pedestal and the floor, while in screeded floor take 250hrs per 100m2 for the insulation, screed, and tiling. Tiling is the most labour intensive element of traditional flooring, and drying time for screed increases programme and risk of damage when wet.The result showed that 32% of time spent laying a traditional floor was non value added time compared with 17% for Technik floor. Techniks 83% added value time demonstrates the efficiency of off-site flooring as well as the reduction in remedial work (WRAP. 2009)At the factory 0.49m3 of waste is generated raising the total waste to 2.81m3 per 100m2. The total waste of Technik flooring of Ropemaker is 24.56m3. While a total 41m3 of waste if screeded floor with tiling had been used on site instead. The screeded floor generates a significantly greater amount of waste compared to the Technik floor.In terms of costs, Technik flooring labour costs was 84/m2, while the screed floor was 114/ m2. Material costs were 140/ m2 for Technik floor, and 147/ m2 for the traditional one. These figures are near, but it is still considerable that Technik is cheaper if we put in consideration that drying time for screed increases programme and risk of damage when wet and the materials associated with the traditional screed design take up a greater area within a warehouse and as such the cost is considerably high er to that of Technik floor. A programme/time economy of 25.7% is made by using Technik flooring, which clearly has a cost saving implication as well. (WRAP. 2009)4.3 Case Study-Emergency Assessment Unit, University Hospital of North Tees.In this case study we are looking at the new revolutionary building which was designed to fulfil the needs of Interserve Project Services/North Tees and Hartlepool NHS Foundation Trust. The building will be located at the University Hospital of North Tees. The purpose-designed and built Emergency Assessment Unit has been required in order to reduce time lag times for much demanded emergency treatment. This is something the Government has planned as to drive down waiting times for patients. The amount of beds are needed to be increased at the Stockton site as well as the site needing to be able to provide a service to those needing emergency surgical care, found centrally on location rather than some distance away. The unit has promised to feature up-to-date emergency care and include specialist staff who can have intercourse quickly and efficiently with a high number of patients thus increasing patient turnover.The solution to these needs was met through a 2.8m Procure 21 project which was awarded to Yorkon manufacturers, based in York, by Interserve Project Services. Off-site construction and the installing of a 42-bed Emergency Assessment Unit was the aim for the new building as its production. The building included 42 steel-framed modules manufactured off-site at York and installed on-site in as little as a few days. Disruption was thereof limited and patients could rest unaware of any commotion. The 1,710m square single storey extension to the pre-existing department was astonishingly and impressively erected in just over six months from beginning to end. The building also can boast a full range of modern well-equipped facilities for any acute medical emergencies.Features are listed as including four-bed wards, single en-suite bedrooms, an isolation ward, high-dependency beds, consulting rooms, ward managers office, waiting area, Quiet room, staff changing facilities and rest room and also an interview room.Incorporated into the design were roof lights to increase any natural light in the centre of the unit and furthermore holds latest technology equipment. The installations of workstations are readily available and can be used at a patients bedside. This building proudly boasts to be one of the first units in the country to offer an electronic entropy board too.Looking to the comments of professionals on the job(p) within the construction of this new high-tech building, we can see the positive influence of off-site technology in providing rapid, quality solutions to much needy clients. The truth as well as speed of construction has impressed many working on the project. The patients are the first top benefit thus impacting greatly on society. A faster completion has resulted in an earlier da te for increasing the hospitals capacity and implementing the hospitals new care programme. The building has proudly been created free of any defect and furthermore feels and appears like a building created in the traditional on-site method. The impact on the people within the building can be felt as they feel secure and at ease with their impressive new surroundings. After significant planning, the result proves to be pleasing and satisfying to all those involved. Impressive design features are said to include isolation rooms, en-suite bathrooms, no touch taps as well as bespoke window blinds, all that was promised. All in all, a roomy and calm working environment which is properly equipped to looking after those that need it has been established.4.4 The Steel Construction Institute (SCI) Case StudyThe Steel Construction Institute (SCI) Study, which was funded by The Department of Trade and Industries (DTI) with support from Corus Strip Products (UK), is started by visits to six co nstruction sites where oft-site construction technologies were being used for data-gathering. A comparative study had been made and followed by the visits to compare the traditional way of construction to off-site construction methods for a 2-storey school where light steel infill panels were used in off-site method against the traditional method, and a 4-storey light steel residential building where off-site modular construction were used against traditional masonry way. The study results showed that off-site construction is by far reducing the disruption to the local residentsThe growing demand for residential housing in cities, towns, and villages of the UK and the scarcity of so-called green field sites, is forcing developers to build on small plots of land within existing residential developments. As housing is built, so the demand for schools, shops, hospitals and empty also increases.Construction on confined urban sites presents developers with various challenges includingTh e construction of urban sites contained presents developers with a number of challenges, such as the lack of working and storage space, the absolute necessary to minimize the impact of all aspects of construction on local residents, and the scarcity of skilled labour working in construction sites. finis Recent experience with modern construction methods showed that these challenges can be met by changing some of the activities of site-intensive products with components manufactured off-site. For example, panels of three two-dimensional and three dimensional modules are supplied in very short time to local conditions and require no storage space on site.Regarding urban disruption, there is some non official essay to suggest that the disruption to the local residents and gravel caused by construction can be greatly reduced by the use of prefabricated lightweight steel and modular solutions. Such methods do not only transfer much of the construction processes off site, but They also significantly reduces the construction time, thereby limiting the inconvenience Caused by site traffic, deliveries, waste clearance and general construction activities.One of the greatest opportunities and challenges for the steel sector is the residential market due to the increase sensation of the physical benefits of steel. As often, home builders and developers are looking at things more closely as the project predictability and speed of construction, and areas that can generate financial returns earlier. Construction in steel, which has always been a technique of off-site construction, is the solution.With its speed of construction, cost-effectiveness, outstanding performance, and unparalleled sustainable qualities, steels off-site construction techniques provides a genuine opportunity for the construction industry to meet growing, and sometimes conflicting demands, in providing affordable housing in todays difficult housing marketBy its very nature, steel based off-site const ruction gives rise to more predictable construction programmes, along with predictable cost, construction quality, programme timing and project handover with faster lead in and onsite project commencement, allowing earlier use and business income return. Ultimately, this can result in the overall construction programme being reduced by up to 60 per cent compared with conventionally constructed buildings.CHAPTER FIVE CONCLUSIONTo conclude, a survey undertaken by Contract Journal revealed interesting findings. Although the survey results indicated that off-site construction is on the rise and gaining popularity, the rise is still lower than the desired figures the industry would have liked to have seen. The surveyModern Methods of ConstructionModern Methods of ConstructionDEFINITIONIt can be defined as the the process to produce or construct good quality buildings rapidly with less consumption of resources Explanation3D publishINTRODUCTION3D stamp (sometimes referred to as Additive Manufacturing (AM)) is the computer-controlled layering of materials to form 3 dimensional shapes. It is particularly useful for prototyping and for the manufacturing of geometrically complex components.Depending on the technique adopted, printing can produce multiple components simultaneously, can use multiple materials and can use multiple colours.Accuracy can be increased by a high-resolution subtractive process that removes material from an over-sized printed item. Some methods include the use of dissolvable materials that support oscillating features during fabrication.Materials such as metal can be expensive to print, and in this case, it may be more cost-effective to print a mould, and then to use that to create the item.G1CONSTRUCTION INDUSTRYIn the construction industry, Construction 3D printing is used to create construction components or to print entire buildings. Construction is well-suited to 3D printing as much of the information necessary to create an item will exist as a result of the design process, and the industry is already experienced in computer aid manufacturing.With the help of building information modelling (BIM), we can facilitate greater use of 3D printing.Also, G2construction 3D printing allows, faster and more accurate construction of complex or modified items as well as it will minimise labour costs and waste. ItG3 also enables us to carry out construction process in harsh or dangerous environments not suitable for a human workforce e.g. cold areas like Alaska and Siberia.G4China has adopted the technique and with the mass movement of population from rural areas to the cities they consider this technique suitable for making cheap houses costing the country (9700) respectively.Materials usedThe most common types of materials used by the printers areRecycled plasticBioplasticsConcreteSynthetic stone-like material made of sand and chemicalsHua Shang TengdaHua Shang Tengda is a Chinese company which has manufactured or printed a two story villa that measures about 4,305 square feet. When put to test the structure was able to retain itself at an earthquake of 8 scales. Moreover, theG5MH2(6 house was all in all finalised within 45 days.The company carried out the process in one go rather than making pieces and then assembling them. The process included three printers operated by a software, which is responsible for formulating the ingredients, mixing the concrete, transmission, and to 3D-print the structure. The team first erected the frame of the house, completed with rebar support and plumbing pipes and then the printed started The printer has a sort of bifurcate extruder that simultaneously lays concrete on both sides of the structural material, allowing it up and encasing it securely within the walls.The concrete used was C30 which weighted approximately 20 tonnes, itG7 had the desired strength and inexpensive as waste wasG8 also utilised as well as wastes resulted from the process were very G9low. The walls of the structure are approx. 8cm thick and is resting firmly on the ground.G10G11ADVANTAGESThe advantages of the system are mentioned as underTIME EFFICIENT3d printers used in construction are very time efficient and a house with the desired strength can be constructed in small time frame.G12G13CLIENT SATISFACTIONWith this process, it is assumed that the client satisfaction is more as they will be given G14a catalogue from which they will be able to choose the structure of their own choice.ACCESSIBILITYG15G16The 3d printers are accessible everywhere even on the moon.G17COST EFFECTIVEThis process of construction is very cheap as the printers consume the minimal amount of raw materials and waste production is very less.G18NEW SHAPES AND DESIGNSThe 3d printers can construct different types of structures ranging from curvilinear to rectilinear and from circular to boxed structures.PRECISIONWith 3d printers, we can achieve more precision as it is a controlled process and is not affected by the environmental conditions.G19ENVIRONMENTAL EFFECTIt is also assumed environmental friendly as the wastes resulting from the process are less. DISADVANTAGESSome disadvantages are mentioned asINITIAL COST AND MAINTENACE COSTG20G21The printers initial cost is very high and requires a cleaning process after 12 hours of operation.LIMITED MATERIALSThe types of materials used in these printers are limited. Some are limited to a single type of material. Also, the printers are unable to great deal with reinforcements. G22TRANSPORTATIONThe transportation may sometimes cause problems because of their sizesRELIABILITYG23Machines cannot be trusted and a major problem may occur resulting in the delays. risingCurrently, there is a research going on at the G24G25University of Southern California which I lead by Berok Khoshnevis.They are testing a fabrication process called contour crafting. The aim of this research is that all the processes involved in construction are self-automated. Khoshn evis hopes to print a residential building(house) in a single print. It will include conduits for electrical, plumbing, drywall, and insulation. His aims are to achieve the possible results by 2020 for residential buildings and by 2025 for high rise.G26G1Inserted ,G2Inserted ,G3Inserted sG4DeletedzG5Inserted sMH2(6G7Inserted neG8Inserted theG9Inserted sG10DeletedaG11DeletedzG12Inserted theG13DeletedaG14Inserted ,G15Inserted CG16DeletedSG17Inserted theG18DeletedsG19Inserted ,G20Inserted EG21DeletedAG22Inserted ,G23Inserted IG24Inserted at theG25Inserted ,G26Deletedin