Tuesday 24 November 2015

O2 Planning- Optimizing Resource utilization in Sustainable housing

Resources are the major source of energy consumed in any construction project. These resources primarily include materials, machinery & manpower. It is very hard to judiciously segregate these three and then seek optimization, as there are way too many interfaces between them. That said, effective planning is pre-requisite for effective resource utilization, which itself is imperative for any Sustainable housing, because optimum resource utilization means optimum energy utilization.
Site logistics planning, i.e., organizing site and resources in such a way that right resource reaches right location in time is a complex process. It is basically done to ensure that construction process flow remains as smooth as possible during execution. It includes planning the numbers and locations for material yards (steel & shuttering yards); Material hoists; Passenger hoists; Tower Cranes; Concrete pumps, batching plants etc. It also demarcates access, approach and movement of resources in around site.
There are two major issues which can be associated with site logistics planning.
  • First is, Improper logistics process flow. About two thirds of the working hours on construction sites are accounted for material search, distances, transportation and other work interruptions, directly attributable to logistics planning. This wasted time does have a cost associated with and subsequently some embodied energy too.
  • Second issue is, over allocation of resources for a particular construction site. It happens primarily to make the logistics planning more effective. But while striving for better process flow, we sacrifice upon the energy efficiency of the construction project, as more resources leads to more energy consumption.
Site logistics planning is essentially outcome of site block planning or site planning. This means the planning of building blocks in the housing, that is, Number of blocks, Location of blocks, etc. defines the site logistics flow and hence their planning.
Site planning is directly affecting the resource planning for housing, hence in order to solve the above stated issues, alternatively in order to make them more sustainable, intervention is needed in planning process.

One-Origin Planning (O2) - The two basic principles of this intervention/philosophy are:
  1. One- Planning should be aimed at changing the plural nature of housing into singular (One). This means that the housing should comprise of one continuous building block instead of a number of separate building blocks. The primary purpose of this is to reduce the number of resources, such as cranes, hoists and concrete pumps, required to make the building accessible for manpower and materials. Less the number of separate building blocks lesser the number of dedicated resources. 
    Furthermore a continuous building block would also increase the workability of various construction activities such as concreting, shuttering, reinforcement lying etc. as these could be planned with more options in terms of working area, accessibility etc. 
    This can be achieved either by planning the overall housing as one single large building, or incase that is not feasible then as a combination of smaller building blocks joined with each other through structural connections vis-à-vis expansion joints. If the number of blocks are too much to be simply connected as then the design could be improvised to achieve the continuation, through branching, extensions etc.
  2. Origin- This means that the planning should evolve from origin, alternately we could say that the building block (prime element of housing) should be the focal point of the site instead of other elements like Green areas or community center etc. These secondary elements of the housing could be placed surrounding the building block. This is also essentially required to make the first principle more viable.   
    When we design building as/at focal center of site, we are providing scope of keeping major construction area concentrated. This means that there will be less distances between various site logistics areas like steel yards, shuttering yards material stores etc. This will drastically reduce both the time and resources required to access and utilize them.
This philosophy is a simple yet effective intervention to optimize the utilization of resources in a sustainable housing. 
In a way this could act as a constraint for designers but a necessary constraint because it would positively improve the sustainable credentials. No doubt it has to be improvised with respect to requirements of site, surroundings, project, and stakeholders.

Following are some schematics to graphically explain the above philosophy.