Ontario Building Code — Part 9, Section 9.25
The primary regulation governing insulation and vapour barriers in Ontario homes is the Ontario Building Code (OBC), specifically Part 9 — Housing and Small Buildings, Section 9.25 — Heat Transfer and Air Leakage Control. This section establishes the minimum thermal resistance (R-value) requirements for all new construction and major renovations, as well as requirements for air barriers and vapour barriers.
The official text of the regulation can be found at Ontario's e-Laws website: O. Reg. 332/12 — Ontario Building Code. This is the authoritative source for all building code requirements in the province.
Ontario is divided into climate zones ranging from Zone 1 (warmest — Lake Erie shoreline) to Zone 7B (coldest — far northern Ontario). All of Renfrew County is in Zone 6, which requires the highest R-values of any zone in Southern Ontario.
R-Value Minimums for Zone 6 (Renfrew County)
The following are the minimum R-value requirements for residential construction in Ontario Building Code Zone 6:
| Building Component | Minimum R-Value (Zone 6) |
|---|---|
| Attic / ceiling (below vented attic) | R-60 |
| Exterior walls (2×6 construction) | R-24 |
| Exterior walls (2×4 construction) | R-20 |
| Floors over unheated spaces | R-32 |
| Basement walls (interior side) | R-20 |
| Basement walls (exterior side) | R-16 |
| Slab-on-grade (vertical edge) | R-12 |
| Unvented roof assembly | R-43 (minimum below roof deck) |
These minimums apply to new construction, home additions, and any renovation that removes or replaces existing wall or ceiling finishes. Simply adding insulation to an existing attic through a hatch does not trigger a requirement to bring the rest of the home up to code, but achieving R-60 in the attic is still strongly recommended for Renfrew County's climate.
SB-12 — Supplementary Standard for Energy Efficiency
SB-12 is a supplementary standard to the Ontario Building Code that was adopted in 2017 as part of the province's efforts to improve energy efficiency in new buildings. SB-12 provides enhanced energy performance requirements that go beyond the base building code. Key elements of SB-12 relevant to insulation include:
- Higher effective R-values for wall assemblies (accounting for thermal bridging through studs)
- Requirements for continuous exterior insulation on walls to reduce thermal bridging
- Improved air tightness targets for the building envelope
- Mandatory energy performance compliance modeling for some building types
While SB-12 currently applies primarily to larger residential buildings and commercial construction, its principles are increasingly relevant to single-family homes. Renfrew County homeowners planning a deep energy retrofit should consider using SB-12 targets as a benchmark, even where the base OBC provides the minimum legal requirement. Many energy efficiency programs offered through Enbridge and the Canada Greener Homes Grant use SB-12-equivalent or higher performance levels.
Vapour Barrier Requirements
Under Section 9.25 of the Ontario Building Code, all new construction in Zone 6 must have a vapour barrier installed on the warm (interior) side of exterior wall, ceiling, and floor assemblies. The key requirements are:
- The vapour barrier must have a permeance of 1 ng/(Pa·s·m²) or less (a standard 6-mil polyethylene sheet meets this requirement)
- All seams must be lapped and sealed to provide continuity
- Penetrations for electrical boxes, plumbing, ducts, and other services must be sealed
- Closed-cell spray foam applied at a minimum thickness of 2 inches qualifies as a vapour barrier
Existing homes are not generally required to add a vapour barrier when adding attic insulation, provided the ceiling finish (drywall or plaster) is not disturbed. However, if you are removing and replacing wall finishes, a vapour barrier must be installed.
Permits for Insulation Work in Renfrew County
Building permit requirements for insulation work vary by municipality within Renfrew County. In general:
- Adding blown-in attic insulation — typically does not require a permit if you are only adding insulation through an existing hatch
- Removing and replacing wall finishes for insulation — likely requires a permit, especially if electrical work is involved
- Spray foam in new construction or major renovations — permit required as part of the overall building permit
- Crawlspace or basement insulation — may require a permit depending on the extent of work
Each municipality in Renfrew County has its own building department. Check with:
- City of Pembroke Building Department
- Town of Petawawa Building Department
- Town of Renfrew Building Department
- Town of Arnprior Building Department
- Town of Deep River Building Department
- Renfrew County Building Department (for unincorporated areas and smaller communities)
Licensing and Certification
In Ontario, there is no specific provincial licence required to install insulation. However:
- Spray foam applicators should be certified by the manufacturer (BASF, Icynene, Demilec, etc.) or by SPFA (Spray Polyurethane Foam Alliance)
- All contractors hiring employees must have WSIB (Workplace Safety and Insurance Board) coverage in good standing
- General liability insurance is strongly recommended for any contractor you hire
- Electrical work (e.g., replacing recessed lights) must be done by a Licensed Electrical Contractor with an ECRA/ESA number
When hiring an insulation contractor in Renfrew County, always ask for proof of WSIB clearance, liability insurance, and spray foam certifications where applicable. See our Hiring Guide for detailed contractor vetting steps.