How much does it cost to build an addition on a house in Riverview?

Building an addition in Riverview typically costs $200-$400 per square foot, with most homeowners spending $40,000-$120,000 for a standard room addition. The wide range depends on the type of addition, foundation requirements, and finish level you choose.

Foundation and structural costs make up a significant portion since you'll need footings extending below New Brunswick's 4+ foot frost line. A simple bump-out addition (8x12 feet) might run $40,000-$60,000, while a full second-story addition can easily reach $150,000-$250,000. Two-story additions are often more cost-effective per square foot since you're maximizing the foundation investment.

The permitting process in Riverview requires a building permit through the Town's Development Services department. Expect $800-$3,000 in permit fees depending on the addition size, plus you'll need stamped drawings from a professional engineer or architect for structural work. The Town follows the National Building Code of Canada 2020 edition, with Tier 2 energy efficiency mandatory for new construction as of May 1, 2025.

Key cost factors include whether you're adding over an existing deck or patio (easier foundation work), matching existing rooflines and siding, and extending utilities. HVAC extensions typically add $3,000-$8,000, while electrical work requires a licensed contractor and NB Power wiring permit. If you're adding a bathroom, factor in $15,000-$25,000 for plumbing rough-in and fixtures, plus a plumbing permit from NB Technical Inspection Services.

Timing matters significantly in New Brunswick's climate. Foundation work must happen between May and October when ground conditions allow proper excavation and concrete curing. Many contractors book spring foundation work by February, so plan ahead.

Professional guidance is essential for additions since they involve structural modifications, foundation work, and multiple trade coordination. A general contractor will handle permits, coordinate inspections, and ensure the addition integrates properly with your existing home's systems.

Your next step: Contact Riverview's Development Services to discuss your specific plans and confirm zoning compliance. Get quotes from at least three licensed general contractors who can provide detailed breakdowns including permits, materials, and timeline estimates for your specific addition goals.