We all know that renovating or building a home is an incredibly complex and stressful undertaking. Why? At the top of the list of answers to that particular why is that it is expensive. I always star the conversation with a client around the budget. Many times I am told that there is no budget... There is always a budget! Let's just get that out of the way. It is up to the client to establish that benchmark and no one else. Of the dozens of individuals and and groups involved in renovations, the effectiveness always comes down to the budget. Without realistic numbers no one can do their job effectively.
I am very honest with clients when I tell them "Whatever you think this project may cost, double it. However long you think it may take to complete this project, triple it." There are a thousand reasons for this bit of truth: You never know what you will find when you start opening up walls. Also (at least in New York City), buildings have condo or co-op boards with a whole host requirements that must be met during any renovation and they will want to see all of the documentation regarding your project and will have their say. Every county has building codes that must be adhered to and your local DOB will need to approve any major work. If you own an older structure, you can count on encountering some unforeseen problems. It's just the way it goes.
On the decorative side, there are lead times for materials and furnishings, cabinetry, fixtures, fabrics, on and on. Everything takes time and you will encounter snags from time to time.
There is an antidote to help alleviate the time crunch: proper planning before construction begins. The more decisions you make in advance of the first swing of a hammer, the better off you will be over the course of your build. You are only as good as the professionals you hire to do the job. Remember that HGTV and the like are TV shows. Edited and programmed for entertainment purposes, it in no way represents the real world. What you don't see behind the scenes are the several semi-tractor trailers and dozens of crew members with equipment, materials that have been provided by sponsors for free... All in the space of 30 or 60 minutes.
Expectations are everything. The more realistic yours are the better off you will be in the end.