split column sentence into multiple lines

Your query looked a bit strange so:
select top(1) p.projectname,s.sitename,
(select 'Contact Person :'+ s.ContactPerson+';'+'Contact Number: '+s.ContactNumber+';'+'Email_Id: '+s.ContactEmailId+';'+'Site Address'+s.SiteAddress+';') as ContactDetails,
s.RosteringDays,
'Weekly Off:'= CASE WHEN w.weekday = 1 THEN 'Sunday'
when w.weekday=2 then 'Monday'
when w.weekday=3 then 'Tuesday'
when w.WeekDay=4 then 'Wensday'
when w.weekday=5 then 'Thursday'
when w.weekday=6 then 'Friday'
when w.weekday=7 then 'Saturday'
else '' end as [WeeklyOff]
from tbl_project_site s
inner join tbl_Project_SiteWeeklyOff w on w.siteid=s.siteid
inner join tbl_project p on p.projectid=s.projectid

-> where s.siteid=w.siteid ????
where s.siteId=<value>