From the Forum – Dig-out under front porch?

Photo by PoPville flickr user Jordan Barab

Dig-out under front porch?

“Has anyone had a contractor do a dig-out or build-out under their porch complying with modern zoning and DCRA regulations?

I think it would be efficient to capture this space as an insulated interior room with my entire basement dig-out. But out of the 17 contractors I’ve interviewed, not a single one has ever built an interior space under a porch. The issue is that normal roof-top decks have two feet between the deck and roof, and since I need the room under the porch to be at least 7 feet tall, the contractors won’t have enough space between the new room’s roof and the porch decking. And they think they can make that work, but haven’t actually done it before, and are therefore quoting me about $40K just for the 90 square feet of roof under the porch.

So I’d love to meet someone who has actually done this, if it’s been done. And find out if it really does cost that much, which is why no one else has done it.”

You can see all forum topics and add your own here. If you are having trouble uploading your question please email me at princeofpetworth(at)gmail Please Note this is NOT an events calendar.

19 Comment

  • not sure how it was done or the costs associated with, but when I bought my home the basement was finished this way. The kitchen for the basement apartment was built in this space off to the side of the entry way. Having the extra space helped a lot with the spacious feel of the basement.

    • Yep….my laundry room is finished out this way. It provides a good sized room. However, i’m reorganizing and will make it a “loft” style bedroom….(open bedroom) to the living space. I’ll move the laundry into the downstairs kitchen.
      Right now it has a small window but i would finish it with glass block (above grade) if i were going to do it again to get more light in. It does not have a front entrance however….the entrance is from the back….difficult to see how it would work.

  • First question is whether this is even your property – oftentimes, and especially for rowhouses, the property line is at the face of building leaving the front porch/steps and lawn in public space. If this is the case you wouldn’t be permitted to build there without paying rental fees to ddot.

    • Right — our property line is right at the front of our house.

    • This would be extremely rare. Sometimes the property line runs through the front yard. Usually, the property line runs at sidewalk, where you would expect it. It really depends on the part of town and can vary even within neighborhoods. You just need to look on your plat. It will tell you where your property line is.
      The notion that this is the general rule in DC is one of those annoying myths that won’t die, like the building height restrictions being tied to the capitol.

      • Your plat doesn’t show where your house is. You would actually need a survey to determine it. Or you would need to know the exact location of your rear property line, and measure from that (through your house)

      • My property line is at my front door, too.

      • It is not extremely rare at all, but I also never said it was a general rule. Look at sheet 1-7 of the public realm handbook posted below if you need further proof. I spend a fair amount of time looking at surveys, I’m not making this stuff up.

      • Kenyon dweller is completely wrong. As “dat” says you need a survey, although you should have got one when you bought the house. A copy would be included with your closing documents. The issue is the so-called “parking” which is essentially an easement the city has on your property if they want to expand the street at a later date. In many, many neighborhoods with porches this area extends midway through the porch or all the way to the front of the house.
        If this is the case, DCRA would deny the permit (you definitely need permits and plans filed for this work). But it would save you some time now if you figure that out ahead of time.

    • Google maps shows property lines. I wouldn’t rely on it but it will get you started.

      • HaileUnlikely

        Slightly more detailed and slightly more authoritative starting point: Pick “Layers” from the top tab, then pick “Property and Land” from the layers dropdown menu, then pick the “Owner Lines (dimensions)” checkbox. You can navigate to your property or enter it in the search box. You still need a survey as this does not show you the location of the reference points from which the measurements are taken, but it will at least give you a clue as to whether the porch is on/over the property line or whether the property line is nowhere near the house at all. You’ll probably still need to get a survey done in order to get the permit for the dig out, but this will at least give you further guidance as to whether or not to even bother.

      • HaileUnlikely

        p.s. I agree with those below who suggest that this enter enterprise is unlikely to justify the cost that it will entail, but anyway, the above is probably the best current free way to find out approximately where your property lines are.

  • I’ve thought about creating a rear addition that sits under the back deck, space currently taken up by my air conditioner and a patch of gravel for drainage. My concern would be I’d be spending a lot of money that wouldn’t necessarily add to home’s value, because as a below-grade addition, it wouldn’t count toward the listable square footage or as an additional bedroom.

    Just a thought.

    • It may not be legal depending on your lot occupancy.

      • If the deck was properly permitted, the deck itself counts toward occupancy so building something directly underneath wouldn’t change occupancy.

  • Our neighbors are incorporating the space under their porch and it has been a nightmare involving long delays with city permitting processes and questionable ability of their contractor. Gas, electrical and water lines all have had to be moved. I think they started the project last fall and it’s not done.

  • Digging that deep underneath your porch means you’ll have to build a foundation wall around the edge of the porch that is not up against the house and in all likelihood also means you’ll have to underpin the part of the house foundation where the porch abuts the house. You’ll also have to waterproof below the porch. This is extremely expensive work that should be performed by someone who knows what he/she is doing and who will get all the proper permits and approvals from DCRA (i.e., it is doubly expensive). I can’t really imagine a more expense way to add square footage to your house. In other words, you probably don’t want to do this.

    • Agree here, a structural engineer recently told me that my porch was sinking due to the laundry under the porch….it needs a 10K helical pier underpinning. T

Comments are closed.