Backyard cottage/DADU owners in Seattle - where are they?
February 4, 2015 2:06 PM   Subscribe

The Mr and I are investigating the possibility of building a backyard cottage/mother-in-law/DADU on our (currently hypothetical future) property in order to supply rental income. We are aware that there are lots of subtleties and gotchas that we would want to learn about from people who have already gone through the process. I imagine there has to be a community out there somewhere. Can anyone help me figure out how to find homeowners who have built backyard cottages themselves so we can hear their stories?

We have read the resources currently available online from the city and are aware of the basic building requirements. I have found a Tiny House meetup group but it seems to be more geared towards people who want to live in microhousing themselves rather than those providing it as a landlord. We have also found a number of sites from consultancies who help you build them or supply prefab units, but we are looking for something more along the lines of a "user group".
posted by matildaben to Home & Garden (10 answers total) 7 users marked this as a favorite
Best answer: I am one. Feel free to memail me (or we can meet up for info exchange), or post more specific questions.

I did not find that there is a group of people doing this who meet up. There are landlord associations, and there are people in the construction/building/architecture business. Also, I know people (from work and other interests) who have done various aspects of building and talk about it. Mostly, we just muddled around and things have taken much longer (and cost more) than we originally expected.
posted by ethidda at 2:15 PM on February 4, 2015

On trying to Google to figure out what the heck a DADU is, I came across this, which looks helpful.
posted by rabbitrabbit at 2:17 PM on February 4, 2015 [1 favorite]

Best answer: Yes, DADU is Detached Accessory Dwelling Unit.

While I don't have direct experience as a home owner, builder or landlord of a detached unit, I have experience on the other side of the counter, with permitting the construction and use of such structures. From my experience, we government folks were happy to talk with you about what you wanted to do before you sank any money into final designs. Detached living units intended for rental separate from the main/primary homes often go beyond "basic" codes, so spend some time with the planning and building folks, if that's at all an option. You could also communicate through email most likely.

My first suggestion: figure out what you want to do (both in building and in renting), and write it up as succinctly as possible. Then make sure you have the correct terminology. For example,your three terms may well have distinctly different meanings for planning/zoning and building. Terms like mother-in-law, granny or guest units often mean that there are limited facilities within the detached unit, and the user of that space can freely come into the main home for the rest of the facilities you expect to have in a modern home. On the other hand, DADU can mean a small secondary unit on the property, specifically intended for rental to an outside party who won't have access the the main home.

If you're new to being a landlord, I'm sure there are general "support groups" or even agencies that can provide good paperwork and guidance for first-time landlords, helping you figure out what you can and cannot do with/to your renter(s).

General tip: put everything in writing, and have the renter(s) sign it, summarizing what is in the paperwork as you review it with them when you first give it to them.

And a more specific tip I heard from a landlord who was also a professional fire person: include some paperwork for your renter(s) to inform them up-front that you'll come in every 6 months on a specific date or day of the month to replace smoke alarm batteries. This way, you can give them plenty of notice that you will be back into the unit on a regular basis. I'm sure there won't be as many surprises for someone who is living on your property, but don't underestimate the creative ways people can (quietly) use a space.
posted by filthy light thief at 2:53 PM on February 4, 2015 [2 favorites]

Best answer: I am a city engineer in the northwest and i don't know Seattle codes issues, but I can tell you some things to get figured out that ANY city will want to approve an ADU.

1. Where is your sewer connection and what shape is it in? You can't, and shouldn't, want to build a structure atop a sewer line that may have to be dug up in the future. So you need to find out if your sewer is int he backyard, alley or street, and where your lateral (line that serves your property and connects to the main is) is located. You need AT LEAST 5' away from this to be safe to build something on. If you have the misfortune of still have orangeburg pipe for your lateral you will have to get it replaced to get a new wye on it for the new dwelling unit. Good idea anyway. Orangeburg ALWAYS fails. always.

2. Are there any easements or utilities without an easement going through your yard? If so you will also need to be clear of those.

3. You need AT LEAST 6' clear separation around a building from other buildings for fire code and it is a really good idea to also be that clear from fences, etc if possible. This is the real reason for building line setbacks (as well as solving 99% of property line disputes).

4. Get your property surveyed and marked by a professional surveyor. It will be 100-1500 depending on your lot and how close a benchmark survey point is. This will likely be required for the permit submittal anyway and it will probably kick up any easements/utility conflicts you don't know about. A title report can also show any encumbrances you may not be aware of.

5. Call the before your dig people before the survey and have them mark your property for any buried lines through and around your property. Trust me-you don't want to miss one of these and have an idiot with a backhoe moment you are on the hook for. A simple oversight can be 10's of thousand to hundred of thousands if you dig up a fiberoptic line. It is astonishing how older neighborhoods accumulate utility lines in really weird locations.

6. As filthy light thief says, your first stop is city hall and your public works/planning desk. Talk to you whoever is on duty and get your requirements and procedures straight from them. They can cover zoning, fees, required professional stamps (survey, engineering, architecture) on documents and general utility locations. We deal with this fairly regularly and we are used to explaining it to inexperienced people.

In my town we LOVE adus (accessory dwelling units) going in. It is SO MUCH better than flag lots, these rentals are rarely, rarely a problem and seem to get top dollar on the resale market for the whole property. People love them. It is a fantastic answer to the low density subdivision problem.
posted by bartonlong at 3:04 PM on February 4, 2015 [2 favorites]

Response by poster: If you haven't purchased a property yet, what kind of questions do you need to answer in order to determine if a house and lot you are looking at will support a DADU? Do you need to get a city engineer out to look at it during the inspection phase?
posted by matildaben at 3:33 PM on February 4, 2015

Best answer: I am also researching this in Seattle and came across this site which I found helpful.
posted by snez at 3:35 PM on February 4, 2015

If you haven't purchased a property yet, what kind of questions do you need to answer in order to determine if a house and lot you are looking at will support a DADU? Do you need to get a city engineer out to look at it during the inspection phase?

No, it's usually covered by zoning. Some residential zones won't allow more than one DU per lot, so you'll want to know what zones allow for higher density, or specifically for DADUs, and you'll want to limit your property searches to those areas. Where I used to live (San Diego), those lots were mostly in older parts of town and nearly all the properties already had multiple units on site. Newer subdivisions (like, post-1950) would generally be limited to one DU. You could have an accessory structure, but it couldn't have a kitchen, basically. There may be additional wrinkles, like only lots above a certain size can have a DADU, or something like that.

Long story short, you'll want to find out from the city where/what zones you're allowed to have a DADU. Your real estate agent should be able to limit your search to those areas/properties, and should be providing you with the zoning designation (which you can cross-reference with your list of zones where DADUs are allowable) when you look at anything. Generally I'd think you're more likely to find a place that already has multiple units on site than one where it's allowed but hasn't happened, unless the zoning has recently changed to allow higher density.
posted by LionIndex at 3:59 PM on February 4, 2015

Response by poster: Seattle allows 1 DADU up to 800 sq ft in single-family zoned areas with lots 4000 sq ft and above. (From the first link in my question.)
posted by matildaben at 4:03 PM on February 4, 2015

Best answer: So, that info page is probably as far as the city is going to go in telling you which lots can have a DADU until you bring them drawings for permitting; you'll probably want those drawings to be professionally prepared. The city probably doesn't have a service to determine whether a DADU would work on a lot, and an inspection wouldn't really do it. You need to have a site plan and lay things out.

If you have an idea of how much square footage you want to build, you could have a design professional help you find a property, and they can quickly determine whether you can get a DADU on the lot while meeting all the other zoning requirements (the parking space, setbacks, building separations, etc). They might even be able to just give you a basic list of dimensional requirements and you can property hunt yourself. The only real X factor whether you can fit everything in within a given lot shape or without having to demo any existing buildings.

The tiny house movement is interesting, but the reason a lot of them are on wheels is because they can't possibly meet building code (minimum room sizes). On wheels, they're not technically buildings.
posted by LionIndex at 8:18 PM on February 4, 2015

I would suggest you go talk to the land use/zoning and building folks before paying for actual plans, though a good architect or designer should be familiar with the rules and regs for building. The permit folks could pull up lot information and do some quick "napkin" calculations to see if an additional dwelling could possibly fit in the open space on a given lot, taking into consideration minimum setbacks and room sizes.

But if you don't own a lot yet, do all the research you can, first with the land use/zoning and building departments, then to the tax office if there aren't records of the existing building on file with the building department. Make sure the existing building is permitted, because you might find that there was an addition that extended the primary building without permits. Depending on how deep the building inspectors check past records (and how familiar they are with that neighborhood/area), you might get a nasty surprise that needs to be fixed before you can build a new structure.

If the existing house is A-OK permit-wise, then locate the utilities. You can always move utility lines, but at an added cost and more time for the project.

Now you have enough information to get an architect or draftsperson to draw up plans. For something this small, you may be OK without a licensed architect. You might even be able to start with pre-approved plans from this or some other jurisdiction, where cities or counties are trying to promote increased density through secondary units.
posted by filthy light thief at 2:26 PM on February 5, 2015

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