INTERIOR NOISE: In terms of noise-related issues, you should expect the building to perform as a typical new construction wood-framed multifamily building that is built to code, which requires a certain level of sound separation. There will be fiberglass sound insulation and extra drywall installed between each unit. In terms of floor construction, the first floor will have a concrete slab, with the second and third floors having wood trusses and wood subfloors topped by lightweight (gypsum) concrete. There will be an acoustical mat between the wood and concrete, fiberglass sound insulation in the cavity, and sound-isolating channels to minimize the "drum" effect. While these measures will be effective, this will not stop all sound transfer.
As in any multifamily building, considerate neighbors are a key ingredient in minimizing noise-related issues. The cohousing model is based on a concept of concern for one's neighbors, which should be helpful in addressing noise-related issues.
EXTERIOR NOISE: Winnebago Street is on the bus line, with buses running on the half-hour during peak hours (with the bus stop a half block away in front of Ford's Gym). There are railroad tracks behind the building, with train traffic generally consisting of a smaller number of cars running at somewhat irregular intervals -- with no train crossing bells at the two closest street crossings. And we are on the flight path of the Dane County Regional Airport, as is most of the near east side of Madison.