Edinburgh's Garden District Presentation Nov 2015

Although you have made an excellent decision in choosing to explore the scope of off site construction, it is important to keep in mind the general benefits or pros of this method when weighing up the restraints/cons. There have been studies undertaken by BCIS which claim OSM can reduced completion time up to 50% faster than traditional methods. With manufacturing taking place in a factory, products will endure strict quality assurance assessments before making their way to site. Adverse weather conditions, site restraints and skill shortages are not a problem for OSM companies so delays are minimal. Other studies have shown that up to 90% of waste is reduced than other methods. Factory based operations mean much less on site disturbances such as less mess, less congestion and less noise. These benefits propose the question, why wouldn’t you want to use OSM? Although this method provides many advantages, there are some factors to consider when selecting your site location.
Bad Publicity – Off site construction has received a lot of bad publicity which has affected the general view of it in the construction industry. When people haven’t researched this method of construction they tend to believe the bad publicity and this steers people away from this method. Complexity – Off site construction comes with many complexities such as the unit having to be well integrated within the building. It also requires a lot of attention to detail when it comes to electricity and sewage. The design has to be constructed with the exact sizes or else it wont fit into the design when it is on site and this can lead to delays as alterations are difficult to carry out. High Costs – There are a lot of costs when it comes to delivering to the site. Due to the large size of some of the pods, they require a special truck as well as an escort just to deliver it to site. Need for project Specific research – There are many factors to consider when choosing which company is going to carry out the off site construction. Time to research the companies and choosing which one is most suitable for the project will hold up construction. Risk Management – this is more to do with procurement however the client needs to know how much risk they are prepared to take in relation with which company they are going to choose to manufacture the off site materials.
Main objective is business and profit from housing units, therefore the larger the site the higher the potential for unit sales. As a result we rejected the following sites based on their smaller net area: Calyx Village, West Hermiston, Gogarbank Village, Easter Hermiston. University Village reasons for rejection: congestion/ traffic issues due to the university being so close and its location of main access routes. The current infrastructure would not manage this volume of traffic particularly during peak times. In terms of the site topography, there are existing pylons which would cause considerable issues when building a housing development. As these pylons obtain huge amounts of power the cost to unground them and relocate can cost around £20,000 per unit- a cost in which this project is likely to want to avoid. Another option of course would be to work around the pylons however there is concluded research into the potential health implications these can cause when living close by. The complications incurred on this site would prove to be a logistical nightmare as well as cost implications, therefore we would not recommend this site for this particular housing/ social development project.
Communication between the offsite and onsite team- effective management and communication between the offsite and onsite teams. This communication is essential for the design to work well. The buildings should be designed so that the onsite team can construct them without any great difficulties. It is common for the offsite team to have no idea how their designs will be implemented on site. This can lead to issues like panels not fitting properly. The attention to detail has to be exact, as there is not a lot of room for error with these construction methods. Closer communication and even the offsite and onsite teams meeting with each other to understand the processes and designs can help these issues to be dealt with. Storage of materials – the materials will most likely only fit in one exact place on the design. Keeping track of these can be an issue and there is a good method of keeping on top of these. RFID tags can be used to tag materials. These send out a radio signal notifying the relevant persons what the material is for and can even store all of the size details and any other important information needed. Labour is also an issue to overcome – a skills shortage means that there are less skilled professionals to put the buildings together. This can be mitigated by training more operatives in this field of work and move more workers into off-site construction methods.
Planning- issues such as site layout and even appearance of development can be a constraint for off-site construction. By extending the pre-construction period, thorough planning of logistics can overcome these constraints. New skill set- clients and project team need to understand the properties of the off-site system selected and revise project process and schedule accordingly. Employing an experienced body to deliver and erect the prefab system will ensure quality, however effective collaboration between contractor, specialist and other team members is imperative. An early appointment of the specialist supplier and installer is important and due to the high degree of system integration calls for strong, collaborative relationship between parties. Project specific research- choosing the correct supplier and system is important to this project delivery. This is something which has been covered in the MEECH ‘critical selection’ report for the client. Thorough research is necessary into the system options to make sure the chosen one appropriately meets the project needs. Selective tendering and an extended tender review period will ensure the most suited supplier is chosen. Also seeking advice from similar residential projects is advised and to review the success of these similar projects under the system they used.
Wide load issues – Restrict the corners on the routes as far as possible, avoid old bridges that cannot take heavy loads, is there enough room on site for the delivery to be taken? If not think about using just in time deliveries. Just in Time delivery – Arranging the delivery of the materials so that they arrive on site just In time to be installed on site. This avoids the materials being stored on site where there is no space and also stops any of the materials perishing whilst being stored on site. Some loads, especially off site materials as they are usually bulky need to be escorted on the road as they can pose too much of a danger to other road users. Have to think if the load will force any road closures? For example, any wide loads travelling over the forth road bridge require it to be shut to traffic for the duration that the load is on the bridge. It is also possible that a police escort may be needed for multiple lorries carrying wide/ heavy loads. The delivery of the material can have a significant impact on the carbon produced. The lorries transporting the material will produce a significant amount of carbon. There is less use of plant on site though so this cuts carbon on site. It has to be weighed up to see what the best option is though. Buildings that advertise as sustainable may produce less carbon but the delivery and installation of materials is not always taken into account. The transportation of the materials can often cause damage to them. For example, the delivery of toilet pods – the pods have been found to have broken tiles, broken fixtures inside due to the rough nature of the transportation.