Plaza North
It is easy to see which parts of Taos are the oldest "town" structures. The first commercial buildings, or those that replaced them to be more accurate since the town burned many times during the early 20th century, are built with a zero-lot line on the front, or built - including portals and walkways - all the way up to the "front" property line on the street. The best place to see this is the main Plaza, where the portals are connected and each building falls into line behind them like a row of soldiers.

Off the main Plaza, the setbacks start to differentiate, and building facades may be placed up to 5' off the property line or sidewalk. Many of the shopping district's structures borrow from the old tradition of haciendas and have an open courtyard - a plazuela - around which the rest of the building's shallow structures ring and into which they open. This indicates a special form of environmental awareness - one that pre-dates everything you see in Taos these days save the Martinez Hacienda and a few other structures. These open courtyards planted with trees and flowers provide a place of beauty, a place to gather, a place of shade, better oxygen, and a place for the well to reside that is central to all users. They also act as a form of air conditioning, as the humid cool shaded center allows cooler air to move through the portals and thusly, the buildings which open onto them. You can see these at Brazos and Ruffin on Bent Street across from the John Dunn Shops, at Taos Blue on Bent Street, at the Wenglert Patio and Kit Carson Home on Kit Carson, at Starr Interiors just south of the Taos Inn, at the cute compound of casitas in Casa Baca Plaza at the corner of Paseo and Queznel, at LaLana Wools/Steven Kilborn as well as Plaza Flores on Paseo Norte just north of Grahams Grille, and some smaller plazuelas at la Loma Plaza and along Ledoux.
Kilborn Plazuela

The Wenglert Patio on Kit Carson
The Taos Inn's interior is one such place that's been transformed from a plazuela into an inside space. That's part of what makes the bar so magnificent.
Inside the Adobe Bar at the Taos Inn, this "lighthouse" structure covers the old well, now converted to a fountain.
 Beyond the main shopping streets, buildings can be anywhere between 10' off the front property line to 50' off the property line. Most often, if there is a setback at all there is also a fence along the property line. Many times the fence is the same material as the house and features a vehicular and a pedestrian gate.

Lessons learned: To design a new infill for any of these areas of town, it is recommended that new construction be placed somewhere between the furthest building setback and the closest of the 2 neighboring buildings adjacent to either side and the 3 closest buildings across the street.