Building Homes or Extensions/Washington DC Row Homes


i own a row home in DC that is over 100 years and am concerned about future development by my neighbors. The origina developer Wardman included back sleeping porches that extend into the backyards and are not attached to the common firewalls.  The porch additions are narrower than the lot width and there is 5 feet or more between each addition. Recently, the city code is allowing developers to replace the small porches with large three story additions that extend out to the property lines to use the entire width of the lot. One development behind my bhome is adding an addition that is less than one foot from the neighors' very old sleeping porches.  I understand that the walls of the addition will be fireblocked but the existing porches owned by the neighbors are not fireblocked.  Also, the lack of space between the existing porches and new addition will make it impossible to repair the siding. Is this good design and safe?

Hi Cecelia, it's probably not the best scenario.  Generally when you have a zero lot line convergence there is a "common wall" between the two properties and each property owner is responsible for his side of the wall.  This doesn't seem to be the case here.  One foot between walls is not enough room to work in however one foot on both sides of the property line will give two feet of working space which may be adequate for minor repairs and painting depending on the heights involved. Something I don't understand is if the old porch is five feet from the property line how can the other property owner build something that is only one foot away from it without encroaching into your neighbors doesn't make sense.

Building Homes or Extensions

All Answers

Answers by Expert:

Ask Experts


Bruce E. Johnson


I can answer any construction related question in regards to carpentry, concrete, drywall, masonry, structural elements of any type of building, residential or commercial. Interior or exterior.


Custom Commercial and residential buildings. Churches, theaters, schools and auditoriums. Most recently I am working with the Catholic Church on several design build committees. I have a website related to scheduling and project supervision. Although my expertise is more related to multimillion dollar commercial, educational and theatrical projects my generous credentials in residential and remodelling construction make me a viable source of information regarding all forms of building questions.

©2016 All rights reserved.