Typically, the time of year is not necessarily a determining factor in starting a construction project. Of course though, it depends on what you are building. Generally the worst months for exterior building work are during the late winter and spring times. The summer and fall are ideal, because the rainfall is usually less and you don’t have to worry about temperature til mid fall. Indoor projects are most generally done year round without major weather delays.
Once the lender approves the loan, most of the time it does not matter on the time of year. Mainly, the client needs to build as quickly as possible to avoid paying additional interest on the loan or paying for a lease when they are not open. Starting a house building project in winter or spring will generally setup the project for weather delays. Sometimes it cannot be helped, with all the studying and analyzing of a project before it starts, it is what it is. Then you just have to adjust to make it work.