NOx gas is not just one gas, it is a way to note several different gasses, in the case of using nitric acid on metals we are mainly speaking of two gasses, nitric oxide (NO) and nitrogen dioxide (NO2). Nitric oxide an invisible gas that is not water soluble, and in the air nitric oxide combines with oxygen to make nitrogen dioxide NO2. nitrogen dioxide is a red-brown toxic gas deadly to yourself and your neighbors. This gas is somewhat water soluble (scrubber design is important for gas and water to have enough contact time to complete the chemical reaction...).
Fume hoods and scrubbers can help when designed properly and are maintained and used properly.
With neighbors as close as the drawing above, even with a very good fume hood and fume scrubbing system, your family and your neighbors could be harmed by these toxic fumes, it would be very hard to build a working and reliable fume hood and gas scrubbing system that could be relied on to keep you your family and your neighbors safe from these gases or refining processes even if you worked outside in such close quarters. My opinion would be to forget about doing this work close to home and your neighbors, move your work to a safer location. Spend time on studying the dangers involved and how to protect yourself and others around you.