Secondary Suite vs. Backyard Suite vs. ADU in Nova Scotia: What’s the Difference?

Secondary suite, backyard suite, ADU, garden suite, laneway home — these terms are often used interchangeably, but they mean different things in the context of Nova Scotia zoning and building regulations. Understanding the distinctions matters because the rules, permit requirements, and grant eligibility can differ depending on exactly what type of unit you are building.

Quick Reference: Key Differences

Secondary Suite

A secondary suite is a self-contained dwelling unit located within the main home — its own entrance, kitchen, bathroom, and living space, but sharing the building envelope with the primary dwelling. Common examples include a basement apartment, a main-floor in-law suite, or an upper-floor unit with a separate entrance. Secondary suites are permitted within the principal dwelling on most residential lots in HRM that allow accessory dwelling units.

Backyard Suite

A backyard suite — also called a garden suite in some HRM documents — is a self-contained dwelling unit in a separate, detached structure on the same lot. It is entirely separate from the main house structurally, with its own foundation, walls, roof, entrance, kitchen, and bathroom. Backyard suites cost more to build than secondary suites because they are essentially a small standalone building, but they offer more privacy. See our guide on Halifax backyard suite rules in 2026 and our backyard suite cost guide for what to expect to spend.

ADU (Accessory Dwelling Unit)

ADU is a planning and policy term, not a regulatory category in HRM’s zoning bylaws. It refers broadly to any secondary dwelling unit on a residential lot. For permitting purposes in HRM, you will apply for either a secondary suite or a backyard suite — not generically for an “ADU.”

Garden Suite

Garden suite is used interchangeably with backyard suite in most Halifax contexts. Some HRM planning documents use garden suite as the preferred term for detached accessory dwelling units. For practical purposes, garden suite and backyard suite mean the same thing in Halifax.

Laneway Home

A laneway home is a backyard suite built at the rear of a lot accessed from a back lane or alley. Halifax has fewer rear laneways than cities like Vancouver or Toronto, so true laneway homes are less common here, though they do exist in parts of the Halifax peninsula. Where a rear lane exists and zoning permits, a laneway home functions under the same rules as a backyard suite in HRM.

Garage Suite or Carriage Suite

A garage suite is created by converting an existing detached garage into a dwelling unit, or by building a structure that combines a garage on the ground floor with a dwelling unit above. Both approaches create a detached accessory dwelling unit subject to the same backyard suite rules in HRM. See our guide on garage conversion costs in Halifax for more detail.

Which One Is Right For Your Property?

Secondary suites are the lower-cost starting point and work well on lots without room for a detached structure. Backyard suites are ideal for larger lots where you want a fully private, standalone unit. Garage suites are the right choice where an existing detached garage is underutilized and can be upgraded to meet dwelling standards. For more on financing your project, see our guide on every grant and incentive available for backyard suites in Halifax.

Get Help Choosing The Right Approach

At Halifax General Contractors, we have built secondary suites, backyard suites, and garage conversions across Halifax and Nova Scotia. Learn more about our backyard suite building services.

For more, see our guides on backyard suite costs, backyard suite permits in Nova Scotia, Halifax backyard suite rules in 2026, and grants and incentives for backyard suites.

Contact us today for a free consultation and feasibility review.