Situate is a planning consulting firm specializing in rezoning, permit and subdivision coordination services for awesome infill projects. In our How To series on Edmonton’s conventional zones, we dive into the nitty gritty of Edmonton’s most common infill zones and overlays.

The RF1 (Single Detached Residential) zone is Edmonton’s smallest scale zone, historically applied throughout the City to allow for Edmonton’s most common form of housing—the single, standalone house. But the RF1 zone has changed a lot over the years, and these days it’s much more than a one trick pony—in addition to allowing for regular single detached houses, the RF1 zone now allows for all sorts of small scale housing, including duplexes, semi-detached housing, secondary suites (aka basement suites), and garden suites (aka granny or garage suites). 

Read on to find out what you can do in the RF1 zone (and what you should watch out for).

BASIC RF1 REGULATIONS: LOT SIZE  

At its most basic level the RF1 zone regulates two main things: the minimum size of the lot and the maximum size of the buildings on the lot. In most areas where the RF1 zone applies, the main building on the lot is a house, or in zoning bylaw terms—a “single detached house”.

For single detached houses, the key thing that controls the size of the lot is the lot width: a lot with one single detached house on it has to be at least 7.5 metres wide (25 feet). Since many lots in Edmonton’s mature neighbourhoods were originally created to be 50 feet wide, all of those lots can now be split into two 25 foot lots (as long as the size of each new lot is at least 250.8 square metres, or about 2,700 square feet). Have a look at Diagram 1 to see what we mean. 

Diagram 1: 50 foot lot split into two 25 foot lots

The RF1 zone also allows duplexes and semi-detached houses to be built. Duplexes and semi-detached houses are buildings that each contain two dwelling units—what differs is how the two dwelling units are connected to each other. A duplex is one building that has two dwelling units stacked on top of the other (see Diagram 2). 

Duplexes require a bigger lot than what’s required for a single detached house: the lot for a duplex has to be at least 10 metres wide (33 feet), 30 metres long, and at least 300 square metres in size (about 3,230 square feet).

Diagram 2: Duplex 

A semi-detached house is also a building with two dwelling units in it. The two dwellings can be attached to each other in one of two ways: either side-by-side (Diagram 3) or front-to-back (Diagram 4). 

For a semi-detached house where the two dwelling units are attached side-by-side, the lot has to be at least 14.8 metres wide (~49 feet), 30 metres long, and at least 488.4 square metres in size (about 5,257 square feet). Keep in mind that the 14.8 metre lot width refers to the width required for the entire building, not the width required per dwelling unit: the lot width per dwelling unit just has to be 7.4 metres.

Diagram 3: Side-by-side semi-detached house 

For a semi-detached house where the two dwelling units are attached front-to-back (Diagram 4), the lot can be slightly more narrow—12 metres wide (~39 feet). However, the minimum lot length and lot size remain the same at 30 metres and 488.4 square metres (~5,257 square feet), respectively. 

Diagram 4. Front-to-back semi-detached house

BASIC RF1 REGULATIONS: BUILDING SIZE

Now that we’ve tackled lot sizes, let’s move on to the second big thing that the RF1 zone controls: the size of the main building. Regardless of whether the main building is a single detached house, a semi-detached house or a duplex, the size of the building is controlled by three key regulations: how much of the lot is covered by the building (the lot coverage), the height of the building, and the distance from the building to the property lines (the setbacks).

LOT COVERAGE 

Lot coverage is controlled by a percentage, and that percentage includes where you live (your single detached house, duplex or semi-detached house), as well as where your car lives (your garage). 

Maximum lot coverage in the RF1 zone is 40%, with 28% allotted to the house and 12% allotted to the garage. If your lot is smaller than 300 m2, the garage coverage gets a boost to 14% to make sure your car (or truck) can fit (see Diagram 5). The RF1 zone has a table that gives all the details about lot coverage, and it’s a good idea to have a look.

Diagram 5. Lot coverage

HEIGHT (AND THE MATURE NEIGHBOURHOOD OVERLAY)

Here’s where you need to pay attention, because it starts to get complicated! Although the RF1 zone theoretically controls building height and building setbacks, it does not control these things in Edmonton’s older neighbourhoods. That’s because height and setbacks in mature RF1 neighbourhoods are controlled by regulations found in a separate part of the zoning bylaw, in an overlay aptly named the Mature Neighbourhood Overlay. Check out this map to see where the Mature Neighbourhood Overlay applies—chances are if you’re doing infill, the overlay applies to you, and you need to make friends with it ASAP.

Here’s what you need to know about height and the Mature Neighbourhood Overlay: although the RF1 zone says a building can be up to 10 metres tall, in neighbourhoods where the Mature Neighbourhood Overlay applies, the building can only be 8.9 metres tall. (Wondering how to measure height? There’s a section in the bylaw for that). The City cannot vary the regulation for height, so if your building is over 8.9 metres tall, be prepared to have your application refused and be ready to go to the Subdivision and Development Appeal Board (more on that in a later post). 

SETBACKS (AND THE MATURE NEIGHBOURHOOD OVERLAY) 

Building setbacks in the RF1 zone are pretty straightforward, but we’re not gonna lie: building setbacks under the Mature Neighbourhood Overlay are pretty darn complicated. 

Under the Mature Neighbourhood Overlay, the front setback—or the distance from the front property line to the front of your house—is either 20% of the lot length or 1.5 m less than the average front setback of the two houses beside you. Whichever number is less. But not less than 3 metres. (And yes, it’s okay if you have to read this paragraph a couple of times before it starts to make sense!)

The rear setback, or the distance from the rear lot line to the back of the house, has to be at least 40% of the length of the lot. 

Diagram 6. Front and rear setback under the Mature Neighbourhood Overlay

The side setbacks—that is, how far the building has to be from the side lot lines—depends on the width of your lot. If the lot is less than 12 metres wide, the setback on each side has to be 1.2 m. If it’s between 12 metres and 18.3 metres, the side setbacks are the same as they would be in the RF1 zone, which is 20% of the lot width or at least 1.2 metres on each side. And finally, if the lot width is greater than 18.3 metres, then the side setbacks must again be 20% of the lot width, to a maximum of 6 metres in total. On corner lots it gets even more complicated, so make sure to read both the RF1 zone and the Mature Neighbourhood Overlay carefully (or contact us, your friendly neighbourhood planning consultant, for a zoning analysis).

Diagram 7. Side setbacks under the Mature Neighbourhood Overlay

We know this is a lot of information, but it’s important to understand setbacks, because setbacks can impact how much of the lot you can build on. After you’ve figured out the minimum setbacks, the area left over in the middle of the lot is what you’re allowed to build on; this area is sometimes called the building pocket. But watch out: the building pocket may end up having more (or less) area than the maximum allowable lot coverage.

What we mean is—if, after you figure out all the required setbacks—only 24% of the lot is left over for building the house, then all you get for the house is 24% of the lot, even though the zone says that the maximum lot coverage for the house is 28%.  By contrast, if you figure out the setbacks and determine that 32% of the lot is left over for building the house, the house can still only cover 28% of the lot, because that’s the max, and the max is the max.

A FEW MORE THINGS TO NOTE!  

DRIVEWAYS AND GARAGES

One last thing about the Mature Neighbourhood Overlay: you’re not allowed to have a driveway or garage facing the street. Garages have to be in the back, facing the rear lane. This is true even if you’re building a new house that replaces an old house that had a front garage—you will be required to remove the driveway and garage, rebuild the curb, and put the new garage in the back. 

SECONDARY SUITES, GARDEN SUITES, PARKING

Ok, we know that was a lot of information about the RF1 zone and the Mature Neighbourhood Overlay! Here’s some last few bits of information (all good things). 

First, a glorious thing about the RF1 zone is that it allows suites! In Edmonton we have different names for different kinds of suites. A suite located in the main house is called a secondary suite (usually but not always located in the basement), and a suite located in the backyard is called a garden suite. Garden suites can be either attached to a garage (above it or beside it), or located in a standalone building.

The best thing about having a house in the RF1 zone is that you’re allowed to have both a secondary suite in your house and a garden suite in your backyard (just watch your lot coverage).

Diagram 8. Principal dwelling, garden suite, and secondary suite on an RF1 lot

That being said, duplexes and semi-detached houses aren’t quite so lucky: you can have a secondary suite in a duplex or a semi-detached house, but not a garden suite in the backyard. For more information on suites, have a look at the regulations for secondary suites and garden suites in the zoning bylaw. 

Diagram 9. Secondary suites in a duplex

Diagram 10. Secondary suites in a semi-detached house

 CONCLUSION 

In conclusion, there’s a lot you can do in the RF1 zone and we hope this article helped you understand a bit more about what’s possible and what to watch for. If you’re planning to build in the RF1 zone, make sure to get familiar with the regulations of the zone itself, as well as the regulations of the Mature Neighbourhood Overlay. Happy zoning! 

This article was written by Situate, Edmonton’s planning consulting firm specializing in rezoning, permit and subdivision coordination services for awesome infill projects. If regulations are getting you down, we can help! Contact us to find out about our zoning analysis and site plan scenario services. We’ll help it all make sense.