The stairs are one of 2 exits from a basement but are not enclosed and the staircase construction is wood.
Residential or commercial?
Check out NFPA 1 2015 ED. Chapter 14 Usable Space Sections 14.6.3 - 184.108.40.206 and Section 14.3.3, Appendix A 14.3.3. NFPA 101 2015 ED. Chapter 7 Usable Space Sections 220.127.116.11.3, 18.104.22.168.3, 22.214.171.124.3.1, 126.96.36.199.3.2. In general there is no storage allowed under wooden staircases. The above NFPA Codes should answer your question. Just my opinion . Hope this was helpful to you.
Retrieving data ...