Sunday, June 12, 2011

Garages and Alleys 3: Reworking the Block

In response to the previous post, commenter Cambias perceptively noted that the example I'd posted of Washington D.C.'s Capitol Hill neighborhood has considerably larger individual lots than those on the new blocks being built up in Capitol Quarter.  This of course makes it easier for the Capitol Hill lots to accommodate both private backyards and detached garages. 

To show that this is an issue of design, not simply acreage, I've taken the same block from the previous post (below, at left) and proposed an alternative configuration with the goal of providing 1) some backyard space for each house with 2) at least one parking space per unit.


By eliminating front setbacks and narrowing the streets by about five feet on the east and west sides -- still enough to allow for parking on both sides of the street -- this goal can be achieved.  On street parking has increased to 65 from 52, thanks to the new center street, serving a total of 64 rowhouses, compared to 54 previously.  Additionally, each house now has a small, courtyard-like outdoor space.  It's just one possible layout of many, and I'm sure people can suggest changes and improvements, but my intent is only to show that this very same area can actually be redesigned to accommodate those features I'd criticized other plans for lacking.

The only complication here is the 1950s era DC Zoning Code, which appears to still require 1 off-street space per every 2 units in this particular residential zone (R-5-B).  This can result in the absurd scenario of interior garages and curb cuts which take away as many on-street spaces as they add, although it appears off-site requirements may now have been waived for houses without alley access.

Update: In response to Alex's comments, here's another arrangement that allows 1/3 of the townhomes space on which to construct garages fronting on the center street.  As to how many people would purchase a garage if offered one as an optional feature, or what the price differential is between homes with the potential of a garage and without, I have no idea (although it's worth mentioning that DC does have the second lowest proportion of car commuters of any major US city).


13 comments:

  1. Zoning code or not, there will still be a desire for enclosed, off-street parking in many of these units.

    The simple spatial reality is that an attached garage means sacrificing a yard (front or back).

    As it is, I think this development in DC is actually below the parking minimums. The buildings on the corners are actually apartments with a few units each, raising the overall density.

    Also, the price point for those rowhouses starts at $600k - a price at which people would be willing to pay for enclosed, attached parking.

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  2. Alex: most of the townhomes in the new development have two car garages, which, even including several additional apartments, would put it above a 1:2 parking-to-unit ratio. Also, on a quick pass, the homes I've found for sale in Capitol Hill without garage parking don't appear to be priced any less than those with it, and some of them are going for over $1.0 million.

    Still, my objection isn't so much to garages themselves as to the assumption that everyone will want one (in a city where only 37 percent drive to work) such that no one who either doesn't have a car, or doesn't mind street permit parking, has the option of buying a cheaper home without it.

    To address your point, though, I'll post a second option that does allow for some garages.

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  3. I've been in several of those units. They may be advertised as two-car garages, but that's probably pushing it.

    If they are two cars, that means two cars parked in order (i.e. the one car is blocked in by the other) - the door is only wide enough for one car.

    Most of the units I've seen instead opt for the one car option and the bedroom/den on that level instead.

    That said, another reason people would want the garage instead of on-street parking is for storage.

    A quick pass of real estate prices on the hill probably isn't sufficient to ascertain the value added of a garage on Capitol Hill - there are too many other confounding variables factored into the price.

    Don't get me wrong, I don't think parking should be required at all. I am saying, however, that it probably should be allowed under certain conditions - and there are people who would want it.

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  4. Don't get me wrong, I don't think parking should be required at all. I am saying, however, that it probably should be allowed under certain conditions - and there are people who would want it.

    The only way to allow garage parking in the first example (mine) would be to permit curb cuts on the fronting street, but even that is counterproductive as it costs almost as many on-street parking spaces. If that were the choice, then, it would make sense to dramatically narrow the fronting street, perhaps to a single one-way lane of travel, since otherwise all that width is serving little purpose. That is the solution in virtually all the Japanese examples Nathan Lewis has linked here and on his site (in fact they are not "curb cuts" there as there is no sidewalk and therefore no curb). Cars are nestled into a front setback of 6-10 feet, or in very small garages.

    The irony of the alley solution is that this attempt to improve the pedestrian experience of the street actually increases the total amount of city land given over to car movement and storage, and further does so at the cost of amenities which might make high-density, walkable living more appealing in the first place.

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  5. Okay, is anyone else coming around to the conclusion that alleyway car access is incompatible with attached garages? Not that it's impossible to mix them, but that you lose the ostensible advantages by doing so.

    All the nice alley garage neighborhoods I've seen, including the Stapleton example I posted in the last post and the older neighborhoods that surround that example, have detached garages. That makes the whole back yard usable and creates a nice enclosed space.

    Stapleton:
    http://maps.google.com/maps?f=q&source=s_q&hl=en&sll=39.756008,-104.89171&sspn=0.008017,0.009334&ie=UTF8&t=h&ll=39.755987,-104.897112&spn=0.004009,0.004667&z=18

    The advantage is that you avoid curb cuts, preserve the view of the building without a "snout," keep the ability to have a back and front yard, add more space for overhead and ground level services like cables and garbage collection, and don't need to add net pavement. That's why the New Urbanists push it.

    On the other hand, the examples of good quality liveable urbanism in the Western Hemisphere don't have many alleyways. San Francisco and Mexico City, the best urban environments in the Americas, don't have alleyways, and I don't think New York or Buenos Aires do either.

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  6. Okay, is anyone else coming around to the conclusion that alleyway car access is incompatible with attached garages? Not that it's impossible to mix them, but that you lose the ostensible advantages by doing so.

    The only exception I can think of would be if the attached garage is used as a platform for a second floor outdoor patio or terrace, but this seems to be infrequently done. I have seen successful examples in the rowhouse neighborhoods of Washington, Baltimore and Philadelphia, though.

    On the other hand, the examples of good quality liveable urbanism in the Western Hemisphere don't have many alleyways. San Francisco and Mexico City, the best urban environments in the Americas, don't have alleyways, and I don't think New York or Buenos Aires do either.

    You are absolutely correct -- this particular type of alleyway is a 19th century invention that in part reflected (I speculate) a way to break up the overscaled 300x300 and 400x400 grid blocks of the typical American city. New York has no need for them since its blocks are only 200 feet wide.

    Unless you have very large buildings, a 300x300 grid block will tend to have a lot of unused center space (this is still visible in many of the residential blocks in the Capitol Hill neighborhood). The alley is a way of breaking down this space into digestible pieces. That this newly accessible space became used for car storage in the 1920s may have been no more than historical accident, I'm not sure, but it doesn't necessarily make it an idea to emulate.

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  7. Charlie's comments regarding curb cuts are valid, but only if the street is wide enough for onstreet parking. If you made a narrower street, not wide enough for onstreet parking, then you would have more space for offstreet parking. If you have a garage with something built over it, then you actually end up with more space.

    In general, I think onstreet parking is a bad idea. Remember, nobody "invented" onstreet parking. What happened is that there were a lot of absurdly wide 19th Century Hypertrophic streets, and then, a hundred years later, somebody invented cars, and then they decided that they would use all that street space for parking. It was an accident.

    New post on these topics:

    http://www.newworldeconomics.com/archives/2011/061211.html

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  8. Another issue here is the typical American conception of a "townhouse." The typical American townhouse is on a very long and narrow plot. Think Brooklyn brownstones on a 25x100 foot plot (2500sf). Obviously, if you have only 25 feet of streetfront and you use 20 feet of them for a two car garage, the streetfront tends to consist of nothing but garages. However, if you had a 40x50 plot (2000sf), then you could have 20 feet of garages and another 20 feet of something else, which would help. 60 foot depth is more than enough. You could have the house on 40x30, which is 1200sf or 1000sf of interior space. Make it three stories and you have a large 3000sf house, or split it into apartments etc. You still have 20 feet of depth for a backyard, which is more than enough for a rather nice backyard. The problem is that more streetfront would tend to require more street, but that is not so much of a problem if you make the streets a lot narrower, basically equivalent to the "alleys" in this discussion, or about 15 feet building-to-building.

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  9. The other obvious solution is the solution used in many of the older Capitol Hill rowhouses - that is a detached garage fronting on the alley instead of an attached garage to the main dwelling.

    There are also some great DC examples of detached garages with accessory dwelling units above the garage itself.

    The need for an attached garage is substantially reduced if one doesn't need to use the car on a daily basis for regular transportation - that added convenience isn't as important if you're using your car less often.

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  10. One other problem with the detached garage is that, if there is enough space for a separate garage, there is likely space for an additional house as well. And I think it is probably safe to assume that the value of the rear portion of a long and narrow Capitol Hill lot for a house is greater than the added value that a garage there contributes to the existing home.

    The accessory dwellings are an indication that this land is not put to its highest and best use, but they are an unsatisfactory compromise (in my opinion) since the owner is not permitted to actually sell the land in the examples I've seen (e.g. Vancouver). When the owner is forced to a) build the new house himself and b) become its landlord in perpetuity, the likelihood of getting alley dwelling units is greatly reduced.

    Better I think to simply let the owner assess the parking situation on his own and sell whatever portion of his lot he wants, and acknowledge that the "alleys" are not special service roads but streets like any other. The process I'm describing took place to a much greater extent in pre-zoning Philadelphia, and the tiny rowhomes built on the alleys are now some of the most desirable housing in the city.

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  11. I think that on-street parking is non-solution. It is exactly the kind of thing that people went to the suburbs to escape. Have you ever lived with onstreet parking? I have, in Montclair, NJ (west of NYC), Jersey City, NJ (on the Hudson west of NYC), and San Francisco in the Mission and Noe Valley areas.

    It stinks. It would be much better, in my opinion, to eliminate it entirely, by making the street narrower. This is why offstreet parking is considered highly desirable in each of these locations.

    However, the idea that you need a whole new street system and a freestanding garage for parking is also rather silly. It is not hard to incorporate parking for one to three cars into a compact format, even a townhouse format. Look at these Victorian houses in San Francisco, each with parking for three cars. There is parking for two cars end-to-end in the garage, and room for one car outside in front of the garage door.

    http://www.flickr.com/photos/podiceps60/3881371118/

    http://www.flickr.com/photos/podiceps60/3881371938/

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  12. I've lived with on-street parking, too. It's fine. It's a good buffer between pedestrians and cars; Jan Gehl claims they can also protect cyclists. It's much better than the alternative, which is off-street parking breaking the street wall and dedicating portions of houses to cars.

    In the New York area, off-street parking is considered desirable not because it's inherently better, but because it's paid and therefore more reliable - no cruising for a spot. In Manhattan there's the additional hurdle of alternate side parking.

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  13. Okay, is anyone else coming around to the conclusion that alleyway car access is incompatible with attached garages?
    - - - - - - - - - - - - -
    Not at all.

    The real culprits are:

    -use of cheap truss-based systems, resulting in tacked-on garages that cannot be incorporated into the house or the garden.

    -setbacks. Who the hell needs a setback on the alley?

    -resistance to excavation. In urban areas, location is a commodity - making a basement area cost effective. Dropping the garage by even 1/2 a story under street level makes it much easier to incorporate into the house or garden.

    There are plenty of 19th century examples where a garden is included in even narrow brownstone lots, and a half-story drop separates the kitchen/servant area from the "upstairs" areas of the house. This lower area links to the garage with a breezeway/storage area, while upper floors access the garden from higher terraces.

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