Works in Jenkins can be activated intermittently (on a timetable, indicated in the arrangement), or when source changes in the task have been distinguished, or they can be naturally activated by mentioning the URL:
http://YOURHOST/jenkins/work/PROJECTNAME/construct
In the undertaking arrangement, there ought to be a Build Triggers area.
This controls how frequently Jenkins polls your SCM for code changes.
When utilizing SVN, you can stand to check as often as possible in light of the fact that the checking isn't costly. So you can advise Jenkins to check each moment or something like that.
Set this to Poll SCM and set the calendar to something like */n * * * * (supplant n with your poll interval in minutes).