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Building a Secondary Dwelling Unit (SDU) in Ottawa - Things to Know

Updated: Dec 17, 2020

What is a secondary dwelling unit (SDU)?

- a SDU is a single, self-contained, rental apartment with its own kitchen and bathroom. While many are basement apartments, a unit can be installed on any floor of the house. SDUs are also commonly referred to as "in-law suites".

Secondary dwelling units provide both homeowners and investors an excellent opportunity to add value to their property. Whether you plan on occupying the main unit & renting the other, or having both units rented, an SDU makes your investment worthwhile. Researchers have noted that a property with a completed, City-approved SDU can be worth up to 50% more than the same property without an SDU! The city of Ottawa allows the addition of a SDU to most detached dwellings, one in each half of a semi-detached, and one for the whole of a duplex.

One of the biggest decisions the investor needs to make when planning to build an SDU is related to utilities. How will the new SDU be heated? Will there be a separate hydro meter? Most investors prefer to have heat & hydro separated between the units, so you don't have to pay your tenants' heating and electricity bills.

However, separating utilities comes at a fairly large expense between utility provider charges, electrician and HVAC expenses. Nonetheless, in the end, you will have peace of mind knowing that if your tenants choose to have their windows wide open in the middle of winter, they are paying for the heat, not you!

Four major requirements to meet city code for an SDU are:

1. Does the ceiling height meet code, especially within the path of egress

2. Natural light calculation, based on the square footage of the living space

3. Fire & soundproofing the SDU from the main unit

4. Adding egress windows

If you are thinking of purchasing a property in order to add a SDU, consider the following:

- Does the zoning permit the addition of a SDU?

- Does the property fall into a neighborhood where a SDU is not permitted? I.E. Queensway Terrace & Rockcliffe.

- Does the basement ceiling height meet code? if not, prepare for extra costs to arise.

- Does the property lend itself to easily add a second entrance for the SDU?

- Does the existing foot print of the space lend itself to a satisfactory sized unit of 1-3 bedrooms?

As you can see, there are many things to consider before making the decision to build a SDU. It is important to go through any city by-laws and familiarize yourself with the rules and legal requirements of a SDU before starting the project.

However, constructing a legal SDU isn't all just fun and games...

- As outlined above, there are lots of things to keep in mind throughout the process of building a SDU. The financial aspect is something that doesn't always come to mind, but there can definitely be a lot of unpredictable additional costs when building the secondary unit.

Filament Construction has successfully completed the addition of secondary dwelling units in the Ottawa area. We offer full service construction packages that cover the entire process of designing and constructing a legal SDU to meet city code. From initial consulting & site visit, to architectural design & drafting, permit application, city inspections, additional utility service coordination, construction and completion - WE DO IT ALL! We even handle the rental market analysis and property management through our sister company, Filament Realty Management Inc.

Sounds like a lot of work? We can help!

Our team at Filament Construction would love to hear from you. Tell us about your project or browse through our available services!


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