The number of TV programmes dedicated to Interior Design and Property Improvement continues to grow rapidly with the result that the viewer absorbs the impression that anyone can achieve a brilliant result entirely within budget and inside the necessary timescales.
Look closer and you will note that Interior Design filmed to a set time schedule will occasionally allow you to glimpse poor finish, unfinished tasks and generally the type of result that you, as a client, would never accept. You would be drawing up a long "snagging list" for your contractors! How many times have you told yourself that you could do better than the featured "designer"? Do you actually have more experience than they do?
Recently "Ugly House to Lovely House" with George Clark has been a really interesting programme. However the common theme is that these projects almost never complete on time and, even more seriously, run over the agreed budget by anything from 25 to 75%. Architects design - it needs specialist quantity surveyors and project managers to monitor the amount spent and time taken.
My recommendation would always be that you should employ experts - they will pay for their fees more than once in the time and money they save you.