Addition to Triplex in West Wash Park. Denver Design/Build Firm?

[Steve K.]

Looking for preliminary advice/feasibility study on an addition to a triplex in Denver (West Wash Park, U-SU-B2 zoning code). Basically we have a 450ft2 studio attached off the back of a traditional side by side duplex. I'd like to pop the top and expand the footprint of the studio and possibly add a 2nd bathroom in order to convert it into a 2bed/2bath with long term goal of selling it as a townhouse (all 3 units are already individually deeded, individually metered with gas and electric, have their own furnaces and water heaters, etc.). Can anybody offer advice and/or recommend a good design/build company who would be familiar with this zoning code, not the most fancy expensive outfit but somebody capable and certainly not the cheapest? Looking to get an idea of whether or not this would be possible and if so ballpark estimate.