In earlier blog posts we introduced the advantages of self build and gave some guidelines on starting up and managing the project. Now we’re going to give a little more guidance on how to complete a self build house project within time and budget.
You can use our calculator to help you work out the budget for the self build project. This should be done by building a spreadsheet for each task or purchase in the project. You should add on a contingency (say 10%) to cover cost overruns and unexpected costs. As you start working with an architect or designer then you will begin to refine your budget. The accuracy of your cost budgets will improve as you replace initial estimates with actual quotes from suppliers and building trades.
One way of controlling self build costs as the self build project progresses is to track completion and actual spend for each task or purchase on a spreadsheet. You can estimate completion percentage and record this as well as entering stage payments to suppliers and contractors. This will compare how much has actually been spent to the percentage of the budget for the work that has been completed. In the spreadsheet you would be able to sum the completed budgets and actual spend across the entire project to allow you to compare what has been actually spent against what should have been spent when looking at actual and estimated completion of tasks and purchases. Here is an example of such a cost control spreadsheet.
Also, you should track the completion of the various tasks and purchases against a schedule. When you have completed the cost spreadsheet you should prepare a plan showing the start and finish date for each task. This can also be done as a spreadsheet and here is an example of a planning spreadsheet. You can combine the information of the plan and the cost spreadsheet and this will give you an indication of how spend will be phased over the self build project. This is very helpful if you need to have drawdown financing arrangements from a mortgage provider. You should also monitor actual completion of tasks against the plan.
If you would like a copy of one of the planning and control spreadsheets please contact us.