@Elaine Lai, @Matt M. is right on a few things: 1. Your construction cost at $175 psf sounds like just a hard cost and is a little low (I'd at least use $180-$185 min at the price point and square footage your'e looking at with lumber prices at a high and steel prices going up etc). As Sloan mentioned earlier, you'll also need to factor in soft costs, so with hard + soft costs you're probably looking at closer to $200-$215 psf.
Your permitting timelines is also idealistic. If you're lucky you may be able to get through permitting in 8 months, but that is not accounting for the time to takes the architect and engineers to do the drawings and design the building, and the city of Denver has a Site Development Plan submittal as well as a permitting submittal. I'd use at least 8-12 months to budget for your schedule before you can even break ground.
In terms of financing, I don't see how you can make it work with hard money, so your best bet is to find a partner, especially someone who has done this type of work since banks want to see a track record with experience. You'll need to bring at least 20-25% down for the construction loan and make sure there's enough income/assets on whoever is guaranteeing the loan - the existing mortgage and equity of the house will get rolled into the construction loan.
Start with a pro-forma, find a mentor or partner, find an architect. I'm curious it seems like you have some specifics about what you can build, so was there already some drawings/ or feasibility site plan done on this? PM me, I'm a developer and architect in Denver, I can help you take a look at all these aspects.