---
title: "Planning a Second Storey Addition in Durham Region"
url: "https://www.jarviscontracting.ca/post/second-storey-addition-contractors-ontario-the-design-build-guide-to-planning-upward"
description: "Planning a second storey in Whitby or Oshawa: the engineer check, 2026 permit fees of $22.37 and $15.56 per m², height limits, minor variances and CLOCA."
publisher: "Jarvis Contracting"
dateModified: "2026-10-13"
---
# Planning a Second Storey Addition in Durham Region

By Jarvis Contracting. Published 2026-08-16, updated 2026-10-13.

A second storey in Durham Region, Ontario starts with an engineer confirming your footings, foundation and main-floor walls can carry a new floor, then a building permit charged at [$22.37 per m² in Whitby](https://media-003-ca.cdn.govstack.com/whitby-ca/media/5aqjt5ww/2026-building-permit-fees-schedule-n.pdf) or [$15.56 per m² in Oshawa](https://media-002-ca.cdn.govstack.com/oshawa-016-ca/media/em3h4lr3/bylaw-33-2009-as-amended-by-by-law-118-2025.pdf), as of October 2026. If the new roof goes over the zoning height, a minor variance from the Committee of Adjustment comes first. Plan the structure and the zoning before anyone draws a bedroom.

## Key takeaways

- A 1,000 sq ft second storey works out to a permit fee of about $2,078 in Whitby and about $1,446 in Oshawa, calculated from the [Town of Whitby 2026 fee schedule](https://media-003-ca.cdn.govstack.com/whitby-ca/media/5aqjt5ww/2026-building-permit-fees-schedule-n.pdf) and [Oshawa By-law 33-2009](https://media-002-ca.cdn.govstack.com/oshawa-016-ca/media/em3h4lr3/bylaw-33-2009-as-amended-by-by-law-118-2025.pdf).
- Height limits are 8.5 m in the R1 to R3 zones of [Whitby By-law 1784](https://media-003-ca.cdn.govstack.com/whitby-ca/media/orfb0rfx/1784_zoning-by-law_2025_consolidation-accessible.pdf) and 9.0 m in the R1-A to R1-E zones of [Oshawa By-law 60-94](https://media-002-ca.cdn.govstack.com/oshawa-016-ca/media/xrthfhqx/zoning-by-law-60-94.pdf), so check yours before design starts.
- A minor variance costs $1,526 in Whitby ([Town of Whitby application form](https://media-003-ca.cdn.govstack.com/whitby-ca/media/txxlnw3w/pl-application_minorvariance.pdf)) and $856 in Oshawa ([City of Oshawa Committee of Adjustment](https://www.oshawa.ca/business-development/planning-and-development/development-applications/committee-of-adjustment/)) for a residential lot.
- Ontario gives the building department 10 business days to decide a complete permit application for a house with no unit above another, under the [Building Code](https://www.publications.gov.on.ca/301880).
- Enlarging your own home doesn't trigger development charges under the [Development Charges Act](https://www.ontario.ca/laws/statute/97d27), and the [Canada Revenue Agency](https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/gst-hst-rebates/new-housing-rebate.html) treats an addition that at least doubles your living space as owner-built for HST rebate purposes.

## Can my house carry a second storey?

Most bungalows can take a second floor, but you only know once a licensed structural engineer has looked at what's under it. The original house was framed and footed for one floor and a roof. A new storey adds a floor, walls, a roof and everything you put in them, and all of it needs a clear path down to the ground.

Here is what gets checked, top to bottom:

- **The main-floor walls.** Exterior walls and any interior bearing wall will carry the new floor. Some get new studs or headers. Where you want a wider opening below, a steel beam or engineered wood beam takes the load, and the posts at each end become point loads.
- **The floor framing.** The old ceiling joists were sized to hold up drywall and insulation, not a bedroom. They're usually replaced or sistered, or a new floor system is built over them.
- **The foundation and footings.** Every point load has to land on something that can take it. Sometimes that's the existing footing. Sometimes it's a new pad footing in the basement. Sometimes the engineer calls for underpinning or for strengthening a wall.
- **The soil and the walls you can't see.** Cracks, bowing block, water staining and old repairs all tell a story. We look for them on the first visit so they don't show up as a surprise the week the roof comes off.

The engineer's report decides this, not us and not you. We frame to the stamped drawings. If underpinning is part of the job in Whitby, the town lists it as a separate [$305 flat permit item](https://media-003-ca.cdn.govstack.com/whitby-ca/media/5aqjt5ww/2026-building-permit-fees-schedule-n.pdf). Budget for the engineering visit before you pay for full drawings: it's the cheapest way to learn whether building up makes sense at all. If the answer is no, our [build up or out guide](https://www.jarviscontracting.ca/guides/build-up-or-out) covers the rear addition alternative.

## Permits and zoning for a second storey in Whitby and Oshawa

A second storey needs a building permit. The [Building Code Act](https://www.ontario.ca/laws/statute/92b23) doesn't let anyone construct a building without one, and an addition counts. Before the permit, though, the design has to fit the zoning by-law for your lot: height, lot coverage and setbacks. If it doesn't, you apply to the Committee of Adjustment for a minor variance, and the permit waits for that decision.

Here is how the two towns we work in most compare, as of October 2026:

| | Town of Whitby | City of Oshawa |
|---|---|---|
| Permit fee, new floor area | [$22.37 per m²](https://media-003-ca.cdn.govstack.com/whitby-ca/media/5aqjt5ww/2026-building-permit-fees-schedule-n.pdf) | [$15.56 per m²](https://media-002-ca.cdn.govstack.com/oshawa-016-ca/media/em3h4lr3/bylaw-33-2009-as-amended-by-by-law-118-2025.pdf) |
| 1,000 sq ft (92.9 m²) addition | about $2,078 | about $1,446 |
| Maximum height | [8.5 m (R1 to R3, By-law 1784)](https://media-003-ca.cdn.govstack.com/whitby-ca/media/orfb0rfx/1784_zoning-by-law_2025_consolidation-accessible.pdf) | [9.0 m (R1-A to R1-E, By-law 60-94)](https://media-002-ca.cdn.govstack.com/oshawa-016-ca/media/xrthfhqx/zoning-by-law-60-94.pdf) |
| Maximum lot coverage | [20% (R1 to R3, By-law 1784)](https://media-003-ca.cdn.govstack.com/whitby-ca/media/orfb0rfx/1784_zoning-by-law_2025_consolidation-accessible.pdf) | [40% (R1-A to R1-E)](https://media-002-ca.cdn.govstack.com/oshawa-016-ca/media/xrthfhqx/zoning-by-law-60-94.pdf) |
| Minor variance fee (residential) | [$1,526](https://media-003-ca.cdn.govstack.com/whitby-ca/media/txxlnw3w/pl-application_minorvariance.pdf) | [$856 per lot](https://www.oshawa.ca/business-development/planning-and-development/development-applications/committee-of-adjustment/) |
| Building without a permit | [greater of $100 or 25% of the application fee](https://media-003-ca.cdn.govstack.com/whitby-ca/media/5aqjt5ww/2026-building-permit-fees-schedule-n.pdf) | [25% surcharge, or 50% with no application](https://media-002-ca.cdn.govstack.com/oshawa-016-ca/media/em3h4lr3/bylaw-33-2009-as-amended-by-by-law-118-2025.pdf) |

Note: fees are from each town's 2026 schedule; the 1,000 sq ft figures are our arithmetic, and the town measures the floor area and sets the final fee. Zoning limits vary by zone, so your lot's zone decides which numbers apply.

A second storey on a bungalow rarely changes lot coverage, because you're building on the footprint you already have. Height is where most second storeys get caught, especially with a steep roof. Setbacks matter if you add a bump-out at the same time. On most urban residential lots, Ontario now treats zoning setbacks as [90% of the by-law figure](https://www.ontario.ca/laws/regulation/060545), outside the Greenbelt and some areas near shorelines, wetlands, valleys and railways.

Once the application is complete, the clock is short on paper. The Building Code gives the building department [10 business days](https://www.publications.gov.on.ca/301880) to issue or refuse a permit for a house where no dwelling unit sits above another, and Saturdays and holidays don't count. "Complete" carries the weight: the provincial form, every schedule filled in, fees paid and the drawings attached. Oshawa says plainly on its permit page that with record application volumes it [cannot guarantee review timeframes](https://www.oshawa.ca/living-here/building-and-renovating/building-permits/), so we plan for questions back from the examiner and a resubmission.

### What's different about building up in Durham Region

These are the local layers we check on every second storey east of Toronto:

- **Which zoning by-law you're under.** Whitby has [three](https://www.whitby.ca/business-and-economy/planning-and-development/zoning/): 2585 for downtown Whitby, 1784 for the former township including Brooklin, and 5581-05 for the Oak Ridges Moraine. Oshawa uses [By-law 60-94](https://www.oshawa.ca/business-development/planning-and-development/development-applications/zoning/).
- **CLOCA.** Near a creek, wetland, valley or the lakeshore, the Central Lake Ontario Conservation Authority regulates [new or enlarged structures](https://www.cloca.com/inquiries-permits). Its 2026 schedule lists a [Minor Permit B at $535](https://www.cloca.com/_files/ugd/6cdd05_ca1ea5bbdaa34f3ca770f69ab8f830e4.pdf) for minor additions and a Standard Permit C from $1,990. CLOCA issued [229 permits in 2025](https://www.cloca.com/_files/ugd/b3995f_39e00c93c1474cd4b56145440a573905.pdf) with an average review of 6.1 days.
- **Heritage districts.** Whitby has [two Heritage Conservation Districts](https://www.whitby.ca/explore-and-enjoy/heritage/), Werden's Plan downtown and Brooklin. In a district, changing the outside of a house needs a [heritage permit](https://www.ontario.ca/laws/statute/90o18), and a second storey changes the outside more than anything. Whitby charges [no fee to apply](https://www.whitby.ca/services-and-payments/building-and-renovating/heritage-permits/), but it adds a review.
- **The airport.** Near the Oshawa Executive Airport, you need [airport clearance](https://www.oshawa.ca/living-here/building-and-renovating/building-permits/) before Oshawa issues the permit.

## Do you pay development charges or HST relief on a second storey?

You don't pay development charges to enlarge the house you live in. The [Development Charges Act](https://www.ontario.ca/laws/statute/97d27) excludes an action whose only effect is enlarging an existing residential unit. Add a separate unit upstairs and that's a different question.

HST is where a full second storey can be worth a call to your accountant. The CRA lists "an addition that at least doubles the living space of your house" as a case where [owner-built rebates can apply](https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/gst-hst-rebates/new-housing-rebate.html), and it names a full second storey on a bungalow as the example. The [Ontario new housing rebate](https://www.canada.ca/en/revenue-agency/services/tax/businesses/topics/gst-hst-businesses/gst-hst-rebates/new-housing-rebate.html) goes up to $24,000. Ontario's [enhanced rebate](https://www.canada.ca/en/revenue-agency/services/forms-publications/publications/notice346/ontario-enhanced-new-housing-rebate.html) for owner-built homes generally applies where construction begins between April 1, 2026 and March 31, 2027, so the start date can matter. A sunroom or one bedroom over the garage won't qualify. Our [HST relief guide](https://www.jarviscontracting.ca/guides/ontario-hst-relief-substantial-renovation) goes through the rules.

## Can you live in the house while the roof is off?

Sometimes, but plan as if you can't. The roof comes off, the new floor goes on and the walls go up, and for that stretch the house is open to the weather under tarps. One Houzz reply to an owner hoping to stay put was blunt: ["your whole house will be a mess"](https://www.houzz.com/discussions/6116203/staying-during-a-second-floor-addition). Another builder on the same forum told an owner to [plan on nine months or more out of the house](https://www.houzz.com/discussions/6519411/putting-a-second-story-on-a-one-story-house-what-to-watch-for). Most posters there are American; the mess is the same here.

What we do about it:

- We plan the roof-off weeks around the forecast and get the house closed in as fast as the framing allows.
- We protect the main floor, but dust and some damage under tarps happen. We'd rather tell you now.
- The new stair takes a bite out of the main floor, and the furnace, ductwork and electrical service often need to change for the extra floor. Decide early if the main floor gets redone at the same time. A quote that leaves out the main floor is where second-storey budgets break.
- If you're staying, we agree in writing which rooms stay usable, which bathroom works, and when water and power go off.

## What does a second storey cost in Ontario?

Our 2026 range for a 600 to 1,200 sq ft second storey is $300,000 to $800,000, before 13% HST, and work on the floor below, like a new kitchen or bathrooms, adds to it. Our permit drawings for an addition run $6,000 to $12,000, and that price leaves out permit fees, HVAC engineering, truss design, committee of adjustment applications and anything unforeseen. What moves the number is the structure under the new floor, whether the main floor is part of the job, and HST. Our [second storey cost guide](https://www.jarviscontracting.ca/guides/second-storey-addition-cost-ontario) breaks it down.

## How we'd plan your second storey

James comes to the house first. He goes into the basement, looks at the foundation and the bearing walls, and asks what you need the space for. If building up looks sensible, we bring in a licensed structural engineer to confirm it.

Design and drawings come from Ceara Jarvis's studio, Juliette Interiors, working with us, so the floor plan, the stair and the new roofline are drawn by people who know what they cost to build. We check the zoning, handle the minor variance if one is needed, and file the permit with the engineer's stamped structure. One crew builds it, framing through finishes. We book the inspections as we go; in Whitby, a request in by [3 p.m. can be scheduled for the next business day](https://www.whitby.ca/services-and-payments/building-and-renovating/building-permits/). At handover you get the house back with the permit closed.

You can see our work on the [projects page](https://www.jarviscontracting.ca/projects). We're writing up more case studies now; the [Greenwood project](https://www.jarviscontracting.ca/projects/greenwood) was a ten-month renovation in Toronto that we took through permit, design and construction. Our [second storey additions page](https://www.jarviscontracting.ca/second-storey-additions) covers the service itself.

## Questions

### Do I need a minor variance for a second storey addition?

You need a minor variance for a second storey only if the design breaks the zoning by-law, most often the height limit. In Whitby's R1 to R3 zones under By-law 1784 the limit is 8.5 m, and in Oshawa's R1-A to R1-E zones it's 9.0 m. The Committee of Adjustment decides, and the fee is $1,526 in Whitby and $856 in Oshawa.

### How long does the building permit take for a second storey in Ontario?

For a house with no unit above another, Ontario's Building Code gives the building department 10 business days to decide a complete permit application for a second storey. The clock only starts when the application is complete, and examiners often send questions back. Oshawa says it can't guarantee review times because of record application volumes.

### Does a second storey addition need underpinning?

A second storey needs underpinning only when the engineer finds the existing footings or foundation walls can't carry the new load. Many bungalows need new footings under point loads instead, or nothing at all. In Whitby, underpinning is a separate $305 flat permit item.

### Do I pay development charges on a second storey in Durham Region?

No development charges apply to a second storey that only makes your existing home bigger. Ontario's Development Charges Act excludes the enlargement of an existing residential unit. A new separate unit is treated differently.

### Does CLOCA need to approve my second storey?

CLOCA needs to approve a second storey only if your lot is in an area it regulates, such as near a creek, wetland, valley or the Lake Ontario shoreline. Its 2026 Minor Permit B for minor additions is $535.

### Can I get an HST rebate on a second storey addition?

An HST rebate can apply to a second storey if it at least doubles the living space of your house, because the CRA treats that addition as owner-built. The Ontario new housing rebate goes up to $24,000, and an enhanced Ontario rebate covers owner-built homes where construction begins between April 1, 2026 and March 31, 2027. Confirm with your accountant before you count on it.

If you want James to look at your house and tell you whether it can go up, [get in touch](https://www.jarviscontracting.ca/contact).