About 1,500 retailers are preparing to reopen on Monday, according to Retail Excellence.
Garden centres, hardwares and farmers marts are among those allowed to open next week.
Office product stores and phone shops are also allowed reopen under phase one of the plan to lift restrictions.
David Fitzsimons, from Retail Excellence, says there'll be a significant cost for retailers when they reopen.
"Monday is a different type of stage, because it's a lot of big format stores like DIY, hardware, garden, the bigger the store the bigger the costs.
"So next Monday it's about €5,000 per store, when you factor in PPE, sneeze guards and training and such.
"Phase 2 will be less, because it's small stores, and obviously the smaller the store the less the cost."
