My chicks are two weeks old - when do I need to let them go outside

[Blue Ridge Hillbilly]

My Barred Rock chicks are two weeks old ( two weeks since they came in the mail) and at this time I do not have my outside run built yet. How soon should I plan on having this done so I can let them go outside? thanks for your help.

 

[True Grit]

Being from the north I'm not too familiar with your climate. Mine were 5 weeks old and fully feathered when I put them out in July. At that time they were flying out of the brooder on a regular basis...