As a licensed architect in San Diego and principal at Ten Seventy Architecture, I delve into the complex yet rewarding process of assessing the development potential of residential zoned lots. This blog post is a walkthrough of my personal approach to evaluating a lot for development, using one of my personal properties in the City as a case study.
Understanding the Basics: Initiating the Evaluation Process
Laying the Groundwork
When I start evaluating a lot, I am embarking on a journey of discovery. I begin by gathering the essential details of the property. This step involves measuring the dimensions of the lot using reliable tools like Google Earth. It's not just about the length and width; it’s about understanding the space as a canvas for potential construction. I scrutinize the lot for existing structures that may influence future design decisions — a two-bedroom house that echoes stories of the past or a makeshift structure that signifies impermanence.
Visualizing the Lot
Visualization is key. Using the measurement tool in Google Earth, I sketch out the possible layouts, envisioning where new structures could rise within the confines of the lot's boundaries. I consider the existing trees, the slope of the land, and even the quality of light at different times of the day. These elements are not merely obstacles but are characteristics that shape the design narrative.
Digging Deeper: Zoning and Regulations
Deciphering Zoning Classifications and Their Implications
Zoning classifications are the rulebook that guides what can be built on a lot. Ensuring the lot isn't within a coastal zone, which would necessitate additional permits, is an early step. Identifying the zoning type, such as RM-2-5, is essential because it informs the range of possible developments. I delve into the San Diego Municipal Code, understanding the permitted uses for the specific zoning designation — whether it's residential, mixed-use, or commercial.
Consulting the San Diego Municipal Code
The San Diego Municipal Code is a tome of knowledge that provides clarity on development feasibility. It informs me of the setbacks — these invisible lines that dictate the permissible distance between a structure and property boundaries. Density limits state how many units can legally be built on the lot, and height restrictions gauge how tall structures can be. These parameters form the invisible framework within which design becomes a reality.
Considering Overlay Zones and Seismic Requirements
Overlay Zones: Complexities and Opportunities
Overlay zones add another layer to the zoning puzzle. Being in a Transit Priority Area, for instance, may offer concessions on parking requirements. I also assess the lot for any geological hazard categories, indicating if seismic or soil tests are necessary, which contribute to project costs and design considerations.
Parking as a Pivotal Design Factor
Solving the Parking Puzzle
Parking is often the unsung hero in urban design. It’s a critical component that can dramatically affect the feasibility of a project. I calculate the number of required spaces based on unit count and bedrooms. This calculation isn’t merely about fitting cars; it’s about ensuring functionality and compliance with city regulations.
Decoding Parking Regulations
Understanding the nuances of parking regulations is like learning a new language. In Transit Priority Areas, opportunities may arise to reduce or eliminate parking requirements, which can be a game-changer. However, these opportunities come with their own set of complexities, such as providing alternative transportation amenities or dealing with right-of-way permits.
Maximizing Development Through ADUs
Harnessing the Power of ADUs for Development Potential
Accessory Dwelling Units (ADUs) offer a unique opportunity to maximize development potential. I closely study the limits and opportunities presented by zoning regulations, considering affordable ADU bonuses that allow for additional units when rented at affordable rates.
Strategically Planning ADUs
Identifying spaces such as garages or storerooms for ADU conversion is a strategic move. I use the Floor Area Ratio (FAR) to determine the maximum buildable square footage while exploring bonuses available for ADU development. This ratio isn’t just a number; it’s a tool that informs how much living space can be created on the lot.
Case Study: My Personal Experience with 1873 Irving Avenue
Applying My Expertise to Real-World Scenarios
Using my own lot at 1873 Irving Avenue as a case study, I delve into its unique features — a 25-foot width, alley access, and exemption from coastal zone restrictions. I outline a potential development strategy that respects these unique features while also aiming to maximize the lot’s potential.
Crafting a Detailed Development Plan
The development plan isn’t just about adding square footage; it's about creating a space that harmonizes with its environment. I consider elements like a butterfly roof and phased construction, ensuring a balance between public and private spaces within the new development.
Concluding Thoughts: The Architect’s Role in Lot Evaluation
From Vision to Value Creation
My role extends beyond design; it's about strategic evaluation and transformation of real estate. With an in-depth understanding of local regulations, physical constraints, and development goals, I navigate through the complex process of transforming a lot into a valuable asset.
Extending an Invitation for Collaboration
If you're considering a lot purchase or development in San Diego, my expertise is at your disposal. Click here to schedule a consultation with me.
Hi, I'm Sean Canning, Principal Architect at Ten Seventy Architecture. And today I'm going to take you through my process to evaluate the development potential of a residential zoned lot. The first thing we have to do is have a lot in mind that we're going to evaluate. So today we're going to use a lot that I own.
It's 1873 Irving Avenue, San Diego, California, 92113. So now that we have this address, I'm going to show you the process that I use. to figure out exactly what we can build on this lot. So the first thing I like to do is I like to pull up the lot on Google Maps or Google Earth. Today we're going to use Google Earth, so I'm going to enter this here.
And you can see the lot is in Logan Heights, right over here in the Diamond District. And we're just going to zoom in so we can see what's on the lot. So right here I can tell there's an existing single family home, and I actually know that's a two bedroom, one bath, because my wife and I own this lot.
This is just a tent structure, so we're going to pretend like this structure is not really there. And the reason I like to use Google Earth is because it has this measurement tool, which is reasonably accurate for what we're trying to do today. So you can just click on the ruler over here, and then bring this into feet, and I can explain that.
This lot right here is 25 foot wide by 140 foot deep. There's no driveway access because all of the parking is off the alley. So it's very important. Most lots are either going to have a driveway like my neighbor does here, or an alley lot, an alley access like we have here. And it's pretty rare when you would have both.
If you do have both, you're... Very lucky because the city won't allow you to have both anymore unless it's a pre conforming condition. So one thing I do want to point out is my lot is only 25 foot wide right here. So it does not include this vacant land right here. So what we're gonna try to determine today is what can I build in the remaining footprint of this lot if I was to leave this existing structure in place.
Let's just take a quick look at the street view so we understand what we're looking at here.
Okay, so here's the house in question. And it does look like there's some sort of shed structure in the back here. And like I mentioned, this is just a tent without a foundation, so we can just pretend like this is not even here because we'll just remove this. hEre we have that two bedroom, one bathroom home.
And there's an additional storage structure in the back. That's going to come into play later on, and I'll explain why. So the first thing I want to do is I want to make sure that this lot is not in the coastal zone. So in this scenario, I'm pretending like I'm about to purchase this lot. I'm pretending like I don't already own the lot.
So the first thing I'm going to do is I'm going to make sure it's not in the coastal zone. If the lot is in the coastal zone, then the way you develop this lot is going to be completely different. That would require a coastal development permit, and that's going to be a very expensive permit. We can take a look right here and we can see that, let me just zoom in a little bit more here,
so we can see that the coastal zone is this blue line and everything west of this blue line is part of California's coastal zone and those lots are more difficult to develop. They require a very expensive coastal development permit. But you can see the blue line generally runs along Route 5, which is right here.
With a few exceptions where it jumps over the east side of Route 5, or it um, exempts certain areas, like this is downtown. This is this weird little peninsula area over in Ocean Beach Point Loma, where this is not in the coastal zone, but this area here is in the coastal zone. We can verify here that my lot is not in the coastal zone, so that's what I'm looking for here.
So I'm just going to close this down. And by the way, you can get to this coastal zone map right here, coastal. ca. gov backslash maps backslash czb backslash. Okay, so I'm just going to close that down. Now the next thing I'm going to do here is I'm going to look up the zoning of this lot. To get to this area here, you can just Google San Diego zoning validation, or you could actually type this address like you see right here.
This will bring up the City of San Diego's official zoning map and here we can put 1873 Irving Avenue and then hit submit and this will explain that we're in the RM 2 5 zone. So this is going to become important later so I'm just going to make a quick note of this RM 2 5 and that's the zone we're in.
So based on that zone, we're going to have a series of setbacks, height limits we're going to be able to build certain things in this zone that we wouldn't be able to build in another zone. So it's very important to first understand the zoning. We could actually come here. Here's Logan Heights right here, and here's the Diamond District of Logan Heights, here's downtown San Diego, and here's Coronado for reference.
And if we zoom in a little bit here, we can actually get a full understanding. of the zoning of the community. I know the RM is the residential multi unit zoning that I'm in right here, RM25. And then right here along Cesar Chavez Parkway, you can see that this is part of the pink CN14 zone, so that's a commercial zoning.
And we can see that most of this diamond district is this RM zoning, so that's all that residential multi unit zoning. And we actually don't have any single family zoning around here. It's all multi family zoning until we get up here into the single family zoning. So it's very interesting. Most of Logan Heights and Sherman Heights is planned with this residential zoning.
Oh, we do have an RS 11 zoning here, an RX 1. That's a single family zoning as well. But most of what we're looking at here is in this RM zone. And I know that our lot is actually... This lot right here. So we can confirm that we're in the RM25 zone. So I'm just going to close this down because we're not going to need this anymore.
And now I'm going to go from RM25. I want to do, I want to check what that zone is all about. So to do that, I'm going to come here. This is San Diego, City of San Diego. Municipal Code, and this is where you find all the chapters. So you can use this address right here and get to this page, or you can just Google San Diego Municipal Code.
Now don't let this page scare you. There's only a couple sections that we really have to review here. The most important is going to be right here in Chapter 13. And we can open that up, and we can come to the Residential Base Zone, because we've already confirmed we are in a Residential Base Zone. So we're going to open that up, and this is going to have all of our RM zoning, RS zoning, RX zoning, and everything that has to do with residential zoning is going to be right here in Chapter 13, Article 1, Division 4, Residential Base Zones.
Okay, so now once we're here, we're just going to go through this real quick. We're actually going to skip everything in the beginning because none of this is going to be really important right now. I want to go to these tables, and that's where I'm going to find the majority of this information. So this is R, E, R, S, R, X, and R, T zones.
We don't have any of those zones, so we're just going to skip that. And this is just a continuation of this table. And this is called the use table. And this table is going to determine what use we're allowed to build in this zone. So we have to keep going down until we get to the R, M table, and here it is.
So you see here on the left side we have use categories and then on the right side we have zones. So we're in this RM25 zone, so that's the second column here. And based on this we can go down and we can see exactly what we're allowed to build in this zone. So I've been through this before and I can tell you right here we're allowed multiple dwelling units.
P stands for permitted, so You have to double check all the footnotes, but we can tell right from the jump that we can permit a multiple dwelling unit in this zone. We're also allowed a single dwelling unit, in case that's actually what's there already. We'd have to double check this footnote 11.
And we're also allowed accessory dwelling units, which is L. I believe that stands for limited use permit. And interestingly enough, we're not allowed to permit guest quarters here. I didn't realize that. But we don't need to permit guest quarters here anyway. Also of note, we're not allowed to permit a junior accessory dwelling unit.
So now that we've determined this from the use table, we're going to go down to the next table, and this is where all the really good information is going to be found. So let's just go down until we reach the next table. And this is all other types of uses in the RM zone, so we're just going to keep scrolling.
And here's the other table. So this is the development regulation table. And we're, again, going to look for the RM zone. If I was in an RS zone, this would be the table I would want to use. But since I'm not in the RS zone, I'm just going to skip this. Until I get to the RM zone.
Here we go. So we have RM25. So in this table, we're the second to last column. And this is going to tell us a couple of things. And really, this is where the majority of the information comes from. The majority of the information that you need to make a decision, whether this is, this lot is worth developing, whether it's worth purchasing whether, what the value of the sale would be, if the buyer is considering their maximum, development potential.
So this is really where the meat and the potatoes are. Once again, RM25. Now the first thing we're going to check is our maximum permitted density is 1500. This is what that means right here. We're just going to put max density equals 1500 square feet. And then the other thing I should mention, which I forgot to put here, is the lot size.
Lot size equals 140 feet by 25 feet, and that equals 3, 500 square feet. Okay, so now that I know the square footage of the lot, and I've verified this through the title, the next thing I'm going to do is I'm going to figure out what my maximum density is going to be. So I'm going to go 3, 500 divided by 1, 500.
And that equals 2. 3. So I'm just going to put that right here. 2. 33, repeating 3. And that's dwelling units. So this means that I can build 2 dwelling units on this lot. And you have to round, if this was 2. 5, I could round up. So if I was able to build 2. 5 units, I could round up and I could say I can build 3 dwelling units.
Okay, so now we've determined that we can build 2 dwelling units on this lot. But I actually want to develop quite a bit more than two dwelling units. So we're going to have to use the accessory dwelling unit part of the code so that I can build accessory dwelling units instead of dwelling units. And in fact, I would almost always recommend after the first dwelling unit that you only develop accessory dwelling units if possible.
And this is possible on this RM zoned lot. In fact, it's an ideal zoned lot to develop. Multiple ADUs. So now I'm going to show you that part of the code. Okay, so a couple, we got to find out a couple other things about this lot. We don't have to use anything in this minimum lot dimension table section here because the lot's already been developed.
So that's only really important when we're start, when we're creating a new lot. Maybe if we were creating a new lot out of a much larger lot, this would come into play. But for our purposes, the lot's already existing and this is not going to apply. So we're going to start here with the setback requirements.
So the first thing you're going to notice is that there's going to be a lot of footnotes here. And I'm not going to go through all these footnotes for the video. I know some of them by heart because I've actually already gone through this. But if you were starting from scratch, you'd actually want to go through each single footnote and make sure that what it says is amenable to your design.
So the first thing you'll notice is we have a front setback. We actually have a minimum front setback and a standard front setback. So our minimum front setback is 15 and our standard front setback is 20. Now every lot is going to, or every zone I should say, is going to have a different setback requirement.
So you could actually see almost all of these RM zones have basically the same setback, but the RS zoning is going to be totally different. The RX zoning is going to be totally different. And you can see this is referring to different footnotes. So some refer to footnote three, some refer to footnote seven.
Now I've already checked what footnote seven means, and it means that 50 percent of the width of my structure 50 percent can use the minimum setback and the other 50 percent has to use the standard front setback. So that means I can have half the building, 5 foot, in front of the other half of the building in this particular zone.
Now, here's our side setback. So we have a 5 foot side setback and it referenced footnote number 8. So again, I've already gone through this practice. because I own this lot, and I know that footnote 8 says that if you have a lot that's under 50 feet, then we're allowed to reduce this to 3 feet. So that's pretty huge, and if I didn't check footnote 8, I would be designing a structure which is uh, 4 feet more narrow otherwise.
Okay, the next one is going to be your minimum street side setback. So this comes into play if you have a corner lot. If you don't have a corner lot, then it's really not going to be relevant. So we can look here, and we can see that I don't have a corner lot. If your lot was on the corner, you'd have a front yard setback and a street side setback, and you'd have to reach out to the city to determine which is the front yard and which is considered the side yard.
So you could put that setback in place. Okay, let's get back to where we were. Okay, so we're in this column again. And this is not going to apply to our lot because we don't have a street side setback. thIs would apply, though, here. We have a 15 foot minimum rear setback. And, again, there's another footnote, so we'd have to research that footnote.
Let me just show you where the footnotes are, so you can do this on your own. If you go down to the bottom of the use chart, we can see all the footnotes are here. Some of our, some of them are explicitly written out, and others refer you to a section, which you then have to read. So we have something like 37 different footnotes for the RM zone table.
Okay, I'm just going to go back up here. And we just went through all the setbacks. So these setbacks are going to be applied onto the lot. For example, we go back up here and we use our tape measure tool.
And we switch this to feet. wherever the front yard property line is. And in this case, it's right about where this fence is. So a lot of people think the front yard property line is at the sidewalk, but that's not always the case. And in fact, in this, on this property, it's not the case. So we're back here.
So if I was to build a new structure right now, half of the structure would be at 20 feet, and the other half could be at 15 feet. So it's pretty close to what we have here. But not exactly, and a lot of times that's the case because this is considered a pre conforming setback. So when this home was built, the municipal code was totally different, and it probably had completely different setbacks.
We're not required to change this, so we can just leave that in place.
Okay then we're going to have a side yard and a rear yard. So we know that our side yard is taken from the property line three foot in. And in this case, I think we have two foot to the existing uh, exterior wall. And that's okay. That's also a pre conforming setback. Now if we're building a new structure, we're gonna have to respect the new setback.
So we're gonna be, let's just assume we're gonna use this footprint here to build a new structure. So we're gonna have a three foot setback from the property line here. And we're gonna have a rear setback. From back here and that rear setback is 13 feet. So that's going to be taken parallel from that rear property line.
Okay, next things that are important here is going to be this one here, max structure height. So we have a 40 foot max height here. So we can go up 40 feet contingent upon this footnote 18 and 37. And I know those are talking about the angled plane restriction. If you're looking to build a very tall structure, you do want to make sure you go up this high.
Or you do want to make sure you research these footnotes. Now, a couple things. Once you go past two stories, you're going to trigger a soils report. That's going to cost you an extra 5, 000. You may want to consider a two story structure only. Now, here's our max floor area ratio. I'm going to explain how this FAR is going to apply to the lot here.
It's a 1. 1. 35. So our max FAR equals 1. 35. So this is what that means. We get to take, we get to take our lot size, 3, 500 square feet, and we get to multiply that by our max FAR. I'm just going to put this on a line below. And this is going to be the maximum amount of square footage that we can build on this lot.
3, 500, that's my site area, multiplied by my max FAR, and we're gonna get 4, 725 square feet. Now, within the constraints of the setbacks and the 40 foot height limit, I can apply this 4, 725 square feet any way I want. So I can make it across two floors, I can make it three floors. And at 40 feet, I can actually probably even make this four floors.
Keep in mind that my existing structure is about 750 square feet. leT's just call it an even 725 square feet. I'd have to subtract that from this, and I can build another 4, 000 square feet. Let's just keep that in mind. Okay, so that's the Max FAR, and that's how that works. Now, there's some accessory use structures.
I would have to turn to this chapter right here to determine exactly how those are applied and we're actually going to go there at the after we finish up with this chapter. Now, this means that these things do not apply. We don't have a ground floor height that generally comes into play for commercial structures.
I don't know anything about this lot consolidation regulation but it doesn't apply anyway. If these did apply, like if we were in this RM1 2 zone, I would want to check this out. Okay, then we have storage requirements. So this is a requirement for storage per unit. We have a private exterior open space.
That's a requirement for the length and width of these private exterior open spaces for every unit we build. We have a common open space, so we'd have to check that out right here. And We're allowed to permit certain architectural projections and encroachments. An architectural projection is an architectural feature which extends past the building envelope.
And an encroachment is something that goes into the setback. Now keep in mind anytime you see something in italic here, that means that it's a defined term. So you can find this in the municipal code, and it'll tell you exactly what encroachments is meant to say. But now since architectural projection is not in italic, that tells me that may not be a defined term.
Of course there's misprints all over this municipal code, so there very well may be a definition for architectural projections. So you'd want to check that out in the definitions chapter of the municipal code. Okay we also have some supplemental requirements, so we'd want to check that out. And we have a requirement here, oops, we're on this column I believe.
We have a requirement for refuse and recyclable material storage, so that's just garbage storage. Visibility area, this has to do with what you can see as you pull out of the lot with your car. Generally, it has to do with driveways. And then we'll just come down here, and now we're into the different RM, the more, the higher density RM zone, and that's going to have its own set of requirements.
So basically that's the most important thing to look at when you're considering any of these lots. And all of those footnotes refer to different sections of this code and that code is going to have different diagrams. Let's see if we can find one. Okay, so this is the minimum and the standard fun setback.
And like I mentioned earlier, 50 percent of that width of the building can come to 15 feet, while the other 50 percent has to be set back at 20 feet. And this is assessed on a floor by floor basis, so we can have something where 50 percent of the ground level extends, and then 50 percent of the second level extends in a different way.
So that's what this diagram is showing. And basically all these things will be diagrammed, so it's very important to go into this section and just really understand exactly what that table is telling you. Okay, now the next thing I want to do is I want to look at the overlay zones. So we know that the base zone is an RM25, but nothing is very straightforward with this, with the code out here in California, so we need to double check what our Overlay zones are.
So the best way to do that is to come to this page here, business. sandiego. gov, and we can go to the residential portal here. This is going to help me do two things. It's going to help me understand my my overlay zones, number one, and number two, it's going to give me an estimate for my permit, which is also going to be very helpful.
So I'm going to go next here, and I'm just going to fill out a couple of these fields, so that it can start to give me a little bit of an estimate. Okay, so I'm going to say new construction, because we're looking to build a new dwelling unit. We're looking to do a companion unit. And we're going to put the address here.
So there's our address. And I'm going to search that.
And it doesn't seem to be working.
Okay, let's just put it like this.
Because they're all in San Diego anyway.
Okay, here we go. So this is the lot. It's already identified the lot. It's saying that we can permit these things with certain limitations. And then as we progress through this, it's going to start adding up some of these fees for us. wE can tell that it's already starting to put together a number for these two fees.
The water and sewer fee, and the combination building permit. This is the permit that we're going to need to do this. Will you demolish or completely remove any structures from the site? I'm going to say no, because we're going to leave that existing structure there. We don't have to worry about that tent structure, because it doesn't even have a foundation, so they don't even need, the city doesn't need to know about that.
Am I going to replace or install a new water meter? I'm going to say neither. And I'm going to move forward here. Okay, so it's already starting to assess these fees. We're going to pay 3, 000 for our combination building permit. And we're going to pay about 3, 830 for our sewer and water fees. Okay, so the sewer and water fees are assessed for every new unit you add.
If I was going to put an addition on that existing home, I would not be assessed these sewer and water fees. If I was to build a new dwelling unit behind it, then I would pay the full sewer and water fees, which is twice this. Because I'm building an accessory dwelling unit, I'm assessed only the 3830, which is 50 percent of the actual sewer and water fee.
That's very important to understand. Dwelling units are going to pay twice this amount. And accessory dwelling units and junior accessory dwelling units are going to pay this amount. And you're only going to pay this for each new unit you add. You're not going to pay this for additions. Okay, so let's say we're going to build a thousand square foot ADU here.
Square footage of garage to be constructed or added. We're not going to add a garage, so we're going to put this at zero. And I'm going to build this at 250 square foot, 250 per square foot. So it's going to be 250, 000, and you can see like this is adjusted now, so I'm just going to hit next. And the fees keep getting, they keep increasing.
Okay, so now we can actually break this down. So this is going to be our plan check fee, I believe, and this is probably going to be our inspection fee. Now there's a bunch of these smaller fees, which it's unclear what they're for. I know we're not supposed to be assessed this mapping fee, so you could actually argue this and you won't be charged this 10 fee for your ADUs or JADUs.
tHis one, I think we're not supposed to be charged this one either. This is a fee just to collect the fees, so this is like my all time favorite fee. It's a fee collection fee. 10. 90 just so that they can collect fees from you. tHen we have a seismic fee, and I'm gonna, that's gonna come up because we are in a seismic zone, and I'm gonna show you that in a second.
We have a records fee, I believe this goes to, so that they can file this on record, and then if you ever need a record they're gonna tell you to go down there and access it yourself, because they don't really do that for you. And a building standards fee, I have no idea what this one is.
But the one fee I can tell you is missing here is school fees, and those are assessed at 4. 08 per square foot. So it would basically be 4. 08 by 1, 000 square feet. And so there's a 4, 080 fee that is missing from this. If you build 500 square feet or less, whether it's an addition or a new construction, you're exempt from that school fee.
Okay, so let's take a quick look at this, and this is really what we're looking for here. This overlay district.
So we can see we're in the transit priority area. That's going to be very important. The parking overlay zones are one of the most important. And I'll explain why in a minute. And we can also tell that we're in this geological hazard category 13. Now this is going to trigger a seismic test. That's a 10, 000 test.
So I know this going into the game, going into this development, that there's going to be an additional 10, 000 cost here. And that's basically going to be 5, 000 for the swales test and 5, 000 for the fault test, which this is going to trigger. So that's one thing that's important to understand. we're also in this transit overlay zone and those are the only ones that are really going to come into play here.
So let's just keep that in mind. Okay, so the next thing that we're going to do is we're going to start to generally plan this. Now we have an existing two bedroom dwelling unit, and we're going to try to build something along here and we're going to leave a little space for parking off the alley so that the person who lives here and the person who's going to live in this structure here can come in from the alley and park.
Okay, so this brings up one of the most important chapters that you have to research, and that's in Chapter 14 here. Now in Chapter 14, you're going to have your parking regulations.
Okay, and this is going to tell you exactly how many parking spaces you have to have. So I'm going to tell you, I'm going to show you how to go through this very quickly. So just stay with me because I'm going to go through this document really fast. Okay, so the first page that you're going to want to see is you're going to want to go to this chart here for multiple dwelling units.
And here we already saw that we're in this overlay zone. Transit area. We're also in this one, parking standards, transit, priority area. So we're in both of these. Now, these are how many off street parking spaces you're going to be required. So we have a two bedroom, so we're required to have 1. 75 parking spaces.
Now, if we were going to plan another two bedroom, we'd have to go 1. 75 by 2. And you can see we're at 3. 5 parking spaces, which we have to round up. To four, and we're not gonna be able to fit four parking spaces on this lot. If you had 3. 25, you could round down and just install three parking spaces, which, based on my experience, this is gonna be the maximum amount, three is gonna be the maximum amount of parking you're gonna be able to get with any reasonable layout here.
So just keep that in mind. We actually really can't do two two bedroom units, dwelling units, on this parking comply. So that's why it's so important to understand this parking regulation and the required off street parking spaces. Now, you might be saying Sean, what if we do this zero parking thing here?
And this is a new section of the code. Because we're in this transit priority area, we can actually justify zero parking. However, you can't say zero parking for one unit and 1. 75 parking spaces for another unit. It has to be a complete site sum. So we can go zero parking for the entire site or we could add them up and go through this formula over here and use the transit area to get a certain amount of parking.
Okay, so why would I not encourage you to go zero parking? There's a couple reasons. First off, this is not free. So the city is going to require you to provide parking amenities to justify this. So that could be providing an entire bicycle fleet to your tenants. It could be subsidizing mass transit for your tenants.
It could be providing an on site daycare. There's a whole bunch of these that you can go through, parking amenities, and you can determine how many parking amenities you need to get zero parking. Now, if you have a driveway, if you try to propose zero parking, the city is going to have you seal up that driveway.
And you really don't want to do that if you don't have to, because that's going to require an additional permit. Which is a right of way permit, and it's going to be difficult, if you ever went back to a parking scenario, then you're going to have to get another right of way permit to cut that curb and to install the driveway again.
Also, if you have an alley access and a driveway, once you seal that driveway up, you'll never be able to get it back. So I really would not recommend, unless you're, there's no other way to do it, I would not recommend you go to zero parking. So how can I get, with three, with a maximum of three parking spaces, And I have an existing two bedroom.
I can see I can install another one bedroom, and that would bring me up to three. So that would be an option that I could use. I can do a two bedroom and a one bedroom and still have only three parking spaces. Okay, hold that thought, and I just want to go through this a little bit more and explain some of these parking regulations.
Okay, so I know at the end of this document, There's the actual dimensions for the parking sizes. And that's another very important thing to understand.
Keep in mind the way the residential parking works versus the way the commercial parking works is like two totally different things. This is the table I want to show you. Minimum off street parking space dimensions. And this is on page 53. Chapter 14, Article 2, Division 5. Page 53. So this is our minimum parking space in San Diego, 8 foot wide by 18 foot long.
However, if we put this against a fence or against the wall next to the wall of an existing structure, the width is going to increase to 9 feet. So now we're at 9 feet 18 inches long. Now, if I have two obstacles, one on either side, let's say a single car garage, where there's a wall on one side and a wall on the other side, this is going to make my...
Minimum width, extend up to nine and a half feet wide. The more obstructions that you park next to, the more wide they require the parking spaces to be. Now also while we're on the topic of garage parking space, if there is a garage door behind the space, then you have to add one foot. So this ends up being nine and a half feet wide by nineteen foot long.
And that's going to be your minimum parking size. for a garage space, or I should say that's the minimum interior garage length and width. They also have a provision here for parallel parking, which doesn't actually come into play too often on residential lots. Okay, so using this and understanding the obstruction, this is why I'm saying I can't get four parking spaces, because I have a 25 foot wide lot here.
So with the fence obstruction here, this requires a 9 foot wide parking space, plus an 8 foot, plus another 8 foot, and we're at exactly 25 feet. So I can do 3 parking spaces off the back here, and they only have to be 18 foot deep. Okay, so
that means that I'm going to leave the first 18 foot here empty for parking. Now, I may build over the top of that, but the ground floor is going to be left empty, so I can get three parking spaces here. And then my development footprint is going to start after that 19 feet right here. Okay, so now that we understand the parking regulations, I want to direct you to another chapter of the Municipal Code, and that's Chapter 14, Article 1, Division 3, Residential Use Category.
This is where your accessory dwelling unit... code section is. And it's only about 8 pages. It starts on page 2. 141. 0302 Accessory Dwelling Units and Junior Accessory Dwelling Units. This is where you're going to find all the information on ADUs. And this goes right up to about 7 or 8 pages. Right up to page 8.
Okay, so let's just go through a couple of these. And I would recommend you just read this entire chapter. But I just want to show you a couple things here. Okay, so first off, we were talking about parking regulations. ADUs and JADUs do not require any parking. So that means I could actually develop a two bedroom ADU and not have to add any more parking that I would not be able to fit on this lot.
So this is a legitimate method to develop this lot.
Let's see what else is important here.
Okay, so this is the section that talks about ADUs developed on multiple dwelling unit lots. So this is the one that really comes, these three Roman numerals are very important to the development of multi dwelling unit zones. So the first one talks about the number of ADUs permitted within the habitable area of an existing multiple dwelling structure is limited to 25 percent of the total number of existing dwelling units, but in no case shall be less than one.
So if I was to have a, an existing multifamily unit multifamily structure, I could make some of that space into an ADU. So in theory, I could take existing duplex and make it into a triplex without adding any more square footage. ADU. Now, before I read number two, I just want to skip here. This says, there's no limit on the number of ADUs permitted within the portions of existing multiple dwelling unit structures that are not used as livable space.
This is the key here. Not used as livable space. This includes storage rooms, boiler rooms, passageways, attics, basements, garages etc. How does that apply to this lot? I know I have an existing storage space here. One option would be to create an ADU out of this space, and I'm actually allowed to add an additional 150 square feet to this footprint and make this an ADU.
It doesn't have to be affordable housing, um, and it would be exempt from certain fees. I have a couple other videos on ADUs which you can look up to understand the nuances of these types of conversions into ADUs and how they're, you can save about 5, 000 of Permit fees by doing this, but I do have an option to create this as an ADU.
So that's very interesting. Now I just want to go back up real quick and talk about number two. So this is like your, the baseline for developing ADUs in your RM zoning here. Two ADUs that are detached from an existing multiple dwelling unit structure are permitted. So this means I can basically build a duplex out here.
Each would be an ADU. And the key is it has to be detached from this one. Now there's no there's no separation distance required for ADUs, so I could make it three foot separate I could make it five feet separate, or I could actually build two walls and just have a little air gap and that would count as a detached structure.
So that may be another method to develop this lot. Okay. A couple other things I just want to point out here. So we already talked about floor area ratio, but let's say you're right at the FAR. Let's say I had already developed this lot and I had 4, 725 square foot built. I wouldn't be able to build any more than that.
However, there's an exception here for an ADU, and you can only do this with one ADU on the lot. But you can go an extra 800 square feet past that FAR maximum. So this means in almost all cases on an RS zoned lot or an RM zoned lot, and actually probably in the commercial zones as well, you can almost always do an 800 square foot ADU.
Okay, so let's see what else is important here. This is the next thing that's very important, and this is what makes this ADU section of the code. Very interesting. So you're allowed to, to use affordable ADUs to get bonus ADUs if you're in the transit priority area. So remember we looked that up earlier and confirmed that we are in that zone.
So this is how this is gonna work. We can do these first two ADUs, just like the code set up here. Now, if we wanted to do a third and fourth, ADU. The third one would be rented at an affordable rate for 15 years and then we would get one bonus ADU. That would be the fourth ADU and that doesn't have to be rented at an affordable rate.
So this is a really good deal. You can rent the, you can rent that third one at a moderate income rate for only 15 years, which is half the time that most other affordable housing density bonuses require. And we can actually do this an infinite amount of time. So that means the 5th ADU could be affordable, the 6th one is a bonus.
The 7th ADU could be affordable, and the 8th one is a bonus. So in theory we could probably build about 8 or 10 units, depending on the size on this lot. So that is a very good opportunity. Now, there's just one last thing I want to do to double check this, and I highly recommend you do this as well, just to be 100 percent sure what you can build, especially if you're looking to use the ADU regulations.
Okay, so in the city of San Diego, and by the way, this only really applies to the city of San Diego, everything that I've discussed here, but in the city of San Diego, it takes a long time for them to update this municipal code because it has to go through a whole series of checks and balances. So what is, what they commonly do is they'll push out these other documents, which they call information bulletins.
So this is information bulletin 400. And this is the information bulletin that talks about your ADUs and your JADUs. And there's two sections here that I want to point out because they're giant loopholes in developing ADUs. So the first one is right here. So this is for single family zones, and sometimes you see a single family zone and it has an existing pre conforming multi dwelling unit structure.
So imagine a duplex in a single family zone. aT first you'd be disappointed because you can't leverage the multi family ADU regulations that allow you to do a lot more. So you're stuck in this single family ADU regulation. Because of the single family zoning. But if you go to this info, InfoBolton 400, we can see that the single family zone exception for multi, for existing multi dwelling unit buildings actually allows you to design this single family zone with the multi family zone provisions.
So this is a huge loophole if you have an existing, pre conforming, multi Unit structure in a single family zone. So a little bit of a tongue twister, but this is a huge loophole for those projects. Now there's one other thing I just want to point out here. And this is actually a contradiction to what it says in the municipal code and we have reached out to the development services department and we've got confirmation on this.
You have to be very careful because the Municipal Code will win out over this InfoBolton document. However, they have confirmed that this is true. wiThin a multifamily zone, just like the one I showed you, where a legally permitted single family dwelling unit structure exists, like I have, the premises may construct ADUs in accordance with the multifamily zone provision, and then here it says, without requirement to construct any other additional standard dwelling units.
So this means, since I have one single family dwelling unit on a multi family zoned lot, I can start developing all my ADUs before I build another dwelling unit proper. Now why is that important? Because this has no fire sprinklers, so any ADUs I build require zero fire sprinklers. But once I build a second dwelling unit, that's going to require fire sprinklers, and then all the sequential ADUs would also have to have fire sprinklers.
So this is actually a really good cost save. Okay, so that is basically a summary of how I will go through my research in what we call the pre design phase. And determine if the lot is viable or maybe how viable the lot is for development. So once again, my name is Sean Canning and I'm the principal architect at 1070 Architecture.
So we're a San Diego based modern architecture and design studio and we focus on custom homes and smaller ADU type designs. And we also specialize in the city of San Diego. modern and minimalist design. If you have any questions, please visit the website, www.tenseventyarchitecture. com, or you can find us on Instagram @1070architecture.
Okay. I hope you found this very informative. And if you have any questions, please feel free to reach out.
