How to Add a Second Story to a Bungalow

Adding a second story turns a single-level bungalow into a full two-storey home, often doubling your living space without touching your lot. It's a substantial project, but it follows a predictable sequence. Understanding each stage helps you plan, budget, and avoid surprises. Here's how a second-storey addition comes together, from first assessment to final finishing.

If you're still at the budgeting stage, start with our breakdown of how much it costs to add a second floor to a bungalow in Ottawa.

Step 1: Assess Feasibility

Not every bungalow is an equally good candidate for a second storey, so the process starts with a structural assessment. A structural engineer evaluates your existing foundation, footings, and load-bearing walls to determine whether they can support the added weight of a full second floor. In many cases the foundation needs reinforcement or underpinning before anything is built upward.

This is also the stage to confirm what local zoning allows. Height limits, setbacks, and lot coverage all affect what you can build. In Ottawa, recent rule changes matter here; see our guide to Ottawa bungalow belt zoning changes.

Step 2: Design The Addition

With feasibility confirmed, the design phase shapes how the new floor works with the existing home. Key decisions include the number of bedrooms and bathrooms, where the new staircase lands (which usually reshapes the main-floor layout), and how the new second storey integrates with the roofline and exterior. Good design balances what you want with what the structure and budget will support.

Step 3: Secure Permits

A second-storey addition always requires a building permit. Your contractor or designer submits stamped architectural and structural drawings to the City of Ottawa for review. Permitting can take several weeks, so it's built into the project timeline early. For a general overview, read how to get a building permit in Ottawa.

Step 4: Structural Reinforcement

Before the new floor goes up, the home is prepared to carry it. This can involve underpinning the foundation, adding or reinforcing footings, and installing beams or steel to redistribute the new loads. This is the least visible part of the project but one of the most important, and a key reason second-storey additions cost more per square foot than ground-level extensions.

Step 5: Remove The Roof And Frame The New Floor

Once the structure is ready, the existing roof is removed and the new second storey is framed. This is the stage where the transformation becomes visible. Because the home is exposed to the elements during this window, crews work to weatherproof quickly, and most families arrange to live elsewhere while it's underway. A new roof is then built over the completed second floor.

Step 6: Mechanical, Electrical, And Plumbing

With the shell framed and enclosed, the systems that make the new space livable go in: extended heating and cooling, new electrical circuits (and often a panel upgrade), and plumbing runs for upstairs bathrooms or a laundry. Doubling your square footage almost always means upgrading these systems to match.

Step 7: Finish The Interior

The final stage is what you actually see and live in: insulation, drywall, flooring, trim, paint, doors, and fixtures on the new level, plus repairs and refinishing on the main floor where the staircase and connections were built. Finishing choices have a big impact on both the feel of the home and the final cost.

How Long Does The Whole Process Take?

From permit to move-in, a full second-storey addition typically runs 4 to 7 months, with larger or more complex projects taking longer. See how long it takes to build a home addition in Ottawa for a fuller picture.

Build Your Second Storey With OGC

Adding a second story is a major undertaking, but with the right team it's a well-managed, sequential process. Ottawa General Contractors handles every stage, including engineering, design, permits, structural work, framing, and finishing, under one roof, so you have a single point of accountability from start to finish.

Explore our second floor additions in Ottawa service page or contact us today to talk through your bungalow's potential.

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