This image of a hole in the floor says quite a bit from a construction angle https://i.sli.mg/2TXOhU.png .

What do I mean by that ? Visual clues and text clues.

Visual: The guy with his arms crossed is standing there and most likely seeing and thinking about the lack of a footer under that brick wall. So now what? Underpinning. But lets get clearance from someone before proceeding.

Enter the text clue. ( Note I'm only using the text parts that are relevant to the actual construction part here, for simplicity, wading through all this trash is tedious)

"Jimmycomet Hmmmmmmm....ok....hmmmm" ( This is the part where he is most likely thinking shit I have a problem)

"jacoplen needs underpinning" ( This may or may not be the guy with his arms crossed, regardless he knows what's needed to do this job)

"jimmycomet @jacoplen no underpinning please!!" ( This is a bit of a low grade panic/desperation kind of comment)

Why no underpinning? I refer you to this document http://os.dc.gov/sites/default/files/dc/sites/os/publication/attachments/OS_DCMR_12A_Building_Code_Supplement.pdf . It's the D.C. construction code.

Underpinning requires not just normal permits, it also requires special permits.

Here is the regular permit required 105.1.4.12 .

105.1.4 Building Permits. A building permit is required for the following activities: 1. New construction, including constructing, adding to or moving a building or structure; 2. Altering or repairing an existing building or structure; 3. Build -out the interior layout of a tenant space within a new building shell; 4. Repair fire damage to a building or structure; 5. Erect or replace a retaining wall; 6. Erect or replace a fence; 7. Erect or replace an awning, canopy, tent or other membrane structure, or similar structures; 8. Install or remove an underground storage tank; 9. Erect a radio, television or other telecommunications tower; 10. Construct, alter or repair a swimming pool; 11. Construct supporting structures for heavy equipment.
12. Underpinning; 13. Change of use or occupancy, increase in load or modification of floor layout of the building or structur

Here are the special permit requirements, note that underpinning is at the top of the list 105.1.11.1 .

105.1.11 Specialty Permits. A specialty permit, as indicated hereafter, is required for the following activities: 1. Underpinning Permit, to underpin existing walls, footings, foundations or other structural load bearing elements. 2. Excavation Permit, to excavate or perform other earth disturbing activities . All work shall comply with soil erosion and sedimentation control regulations specified in 21 DCMR Section 502.1 and the storm water management regulations specified in 21 DCMR Section 526.1. 3. Sheeting and Shoring Permit, to install excavation and sl ope stabilization systems. 4. Grading Permit, for grading, reg rading or land filling operations. All work shall comply with soil erosion and sedimentation control regulations specified in 21 DCMR Section 502.1 and the storm water management regulations s pecified in 21 DCMR Section 526.1. 5. Capacity Placard Permit, to obtain approval of the posted maximum occupant load for the placards required by Section 1004.3. 6. Capacity Increase Permit, to secure approval of an increase in allowable occupant load for a building or premises. 7. After -Hours Permit, to engage in construction, installation, maintenance, alteration, repair, demolition, or razing activities outside normal working hours, subject to noise regulations set forth in 20 DCMR chapters 27 and 28, 14 DCMR §2515, and the “Georgetown Project and Noise Control Amendment Act of 2004”, effective December 7, 2004 ( DC Law 15- 214;. For the purposes of this permit, normal working hours shall be from seven (7) a.m. to seven (7) p.m., Monday through Saturday, exclusive of legal holidays.
8. Tower Crane Permit, to install cranes or other similar hoisting devices, in public space or private property.

Why is this important? please see https://voat.co/v/pizzagate/1454758 for my previous thoughts and observations . It's important because when you start undermining walls and other structural elements things can go from bad to worse in no time at all. This is why they have engineering departments. Can you just imagine the back and forth if they were to follow the permitting process? It would go something like this-

jimmycomet : "Hello mr. building department engineer, I need a special permit for underpinning"

mr. engineer : " No problem, let me look at your file, what would you like to build?"

jimmycomet : " Oh, nothing much, just an underground network of tunnels to supply my murder deathroom with ...."

This is why finding the permit trail could be key, along with historical engineering drawings and prints. Turns out you almost need a permit just to wipe your ass in D.C. If there is no permit trail to be found then it becomes a public safety and health issue, drawing even more attention and reason for inspections and on and on.