Built the same way with the same materials we have also constructed many fireplaces, fire pits and entertainment units built as part of an over-all backyard design. Outdoors it is usually safer and simpler to use gas log fireplaces and gas fire pit inserts. Ventless gas log fireplaces are designed for safe use with little or no ventilation indoors so outdoor use means the design is the focus and a chimney or ventilation system does not drive up the price to levels that cancel the job.