1. It forces you (the client/owner) to think about what you want. Rather than a generic thought like “tile would be nice on the bathroom floor”, you need to do your research and be more specific. What type of tile? What look do you want? What colour? Is there going to be tile on the walls? If so, what style/colour, etc.? Start with the end in mind.
2. It provides a more accurate representation of the realcosts and schedule. Budget ‘blowouts’ typically occur because the client/owner guesses the cost and time which is rarely accurate.
3. It makes it easier for all suppliers (consultants, builders, sub-trades, etc.) to provide more accurate pricing. My experience in the industry has shown that projects flow much more smoothly from both a time/cost perspective when a scope statement is presented to the participants in the project. Expectations are clear with less guessing.
4. The client/owner is able to make informed decisions before the job starts. Much better to undertake ‘value engineering’ of the scope to fit in with the budget prior to the commencement of construction. The client/owner is being reactive rather than proactive and this affects the cost/time and ultimately, the end result.