Think of your residential renovation in terms of four basic concerns: scope, schedule, cost, and quality. The smallest measurable item of a residential renovation is a task. A task is defined in terms of the project deliverable it accomplishes. A project deliverable is defined prior to implementation in terms of scope, schedule, cost and quality. In residential renovations it is far more likely that these concerns will exceed estimates when the task is actually completed.
Each of these concerns can be considered in terms of the resources that will be required to complete a task. Scope refers to the boundaries that define the edge of the task. What is part of the task deliverable and what is not included as task deliverable?
The difference between what has been planned, or estimated, and what is actually required to complete the task deliverable, is considered the risk factor for the task – the percentage variance between what was estimated and what was predicted that could affect the estimate.
Schedule refers to the timeline for the task. What is the earliest start date for the task? What is the latest start date? What is the earliest date the task can be completed by? What is the latest date the task can be completed by? How much time has been estimated to complete the task? How much time has been allocated to account for risk?
Cost refers to the amount of money that needs to be budgeted for the task and the actual amount of money that has to be paid to complete the task. Cost is a consolidation of resource expenditures required to complete the task. In residential renovations, these resources can be organized in terms of project process and knowledge area. There are costs associated with initiating, planning, implementing, monitoring and controlling and closing a task. Every task involves project integration, scope definition, scheduling, resource management, quality management, human resources, communication, risk management, procurement and stakeholder involvement.
Costs are predicted using an estimate. The estimate can be structured for worst-case, best-case and moderate scenarios. In residential renovations, one particular area that can greatly affect task concerns is degree of technical difficulty. Technical difficulty in residential renovations is of particular concern because every task in a residential renovation is building new onto old, and, in many cases, matching new to old on more than one point of attachment.
Technical difficulty should be factored into every task and accounted as a risk factor.
In residential renovations, the cost of a task is normally calculated on a $1 labor + .30 materials = $1.30 ratio. ie. if a task is estimated to cost $100 for labor, the materials charge will be $30. In addition to these hard resource costs, there are additional costs that have to be factored in for every task. These are project management, site supervision, contingency, and contractor mark up. Taxes have to be collected on every invoice. These rates vary but can be calculated at 10% project management, 10% site supervision, 15% contingency, and 20% contractor mark up.
If the price of labor is calculated at $45 per hour (skilled carpenter) the cost breakdown for a typical task follows:
The featured image for this post shows the underside of our second floor toilet. As you can see the subfloor has been destroyed and we now know why the tiles are cracking around the toilet.
At present we are planning the layout and installation for beam structure to repair floor sag around the stairs. We need to do this before installing our laundry upstairs or else the working of the machine would eventually cause a cave-in.
Planning for scope, schedule, cost and quality on this deliverable is complicated by the technical difficulty of installing new beams between existing structure of the second floor and the main floor. We did plan for this rebuild and the structure in the basement was installed to support the new beam structure. However, the technical difficulty is a key factor in designing for this task.
In addition to installing new beam structure under an existing second floor, we also have to contend with the original heritage staircase. We must keep this staircase intact or we will be forced to build a new one to code, which would change the entire layout of the main floor and upstairs.
To add to the difficulty, the wall that is at the centre of this new beam install is the mechanical wall for the household.
This wall has to be preserved, and then the backing plywood has to be replaced as part of the entire installation.
In the instance of this task, investing in planning is our highest priority. Installation will be difficult but not impossible. However, if we do things out of order, it could seriously run up the cost of the task. We are forgiving schedule constraints in the interest of accomplishing all the scope we want to address and control and monitor costs while getting a high quality finish.