Can I sell a duplex and 1031 into a new build that I already own?

[Jason Boice]

I'm doing a new build that will be a future STR, however, I have run out of money during the build. I am going to sell a duplex that I have around $100k in equity in to put towards the new build. Can I use a 1031 Exchange with the profits from the duplex sale to put into the new build if I already own the new build?

Was hoping to avoid paying capital gains on the duplex profits since I am just re-investing them into another project. Thanks.