25:8 Architecture Ottawa & Gatineau Area
25:8 Architecture & Urban Design — a design-led architecture firm based in Ottawa. We collaborate with homeowners, developers, and business owners across Ottawa and Gatineau who want buildings with real vision, built right the first time.
Custom homes · Home additions · Commercial · Multi-unit · Building permits · Heritage
Architecture & urban design
services for Ottawa & Gatineau
From architecturally ambitious custom homes to civic institutions — we bring design vision and deep local expertise to every project across Ottawa and the Gatineau region. Our best work happens when clients give us room to think boldly.
Residential
Custom homes, additions, and renovations designed around how Ottawa and Gatineau families actually live — with deep knowledge of local zoning, heritage overlays, and building code on both sides of the river.
- Custom home design
- Home additions & extensions
- Secondary dwelling units (SDUs)
- Laneway & garden suite design
- Accessible & aging-in-place design
Commercial
Office fit-outs, retail, and mixed-use developments that reflect Ottawa and Gatineau's growing business communities — from Hintonburg and Wellington West to Gatineau's emerging Plateau district.
- Office & co-working design
- Retail & restaurant interiors
- Mixed-use developments
- Tenant improvement drawings
- Commercial permit packages
Multi-Unit Residential
Low-rise and mid-rise multi-unit buildings designed to Ottawa's intensification policies and Gatineau's urban plan — stacked towns, triplexes, and purpose-built rental housing that add real value to their streets.
- Stacked townhouses
- Triplex & fourplex design
- Purpose-built rental housing
- Garden & laneway suite developments
- Site plan control support
Institutional
Civic, community, and institutional facilities across Ottawa and Gatineau — spaces that serve diverse publics and reflect the bilingual, multicultural character of the National Capital Region.
- Community & cultural centres
- Faith & assembly buildings
- Educational facilities
- Civic & government spaces
- Accessibility compliance (AODA)
The architect who knows
both sides of the river.
For homeowners in the Glebe, developers building along Gatineau's Main Street, and businesses setting up in Kanata North — here's why clients across the National Capital Region keep coming back to 25:8.
Ottawa's Official Plan, heritage designations, intensification corridors, Gatineau's Plan d'urbanisme — we navigate both municipal frameworks daily. One firm, two cities, no surprises.
Heritage properties in Sandy Hill, tight infill in Hintonburg, riverfront sites in Gatineau, or large redevelopment parcels in Barrhaven — give us a constrained site and we'll find the design that makes it work.
Ottawa's freeze-thaw cycles, OBC requirements, the National Capital Commission's design guidelines, and the region's mix of Victorian, postwar, and contemporary fabric — we design from the inside out, for this specific place.
Not a junior drafter. Not a project coordinator. A licensed OAA architect on every call, every site visit, every permit submission. One point of contact, full professional accountability.
Recent projects
Ottawa & Gatineau projects — Residential · Commercial · Multi-unit · Institutional
Full Portfolio at 258arch.com ↗Design is strategy.
Strategy is future.
Every 25:8 project follows a rigorous three-phase framework — built around your site's specific opportunities, constraints, and the planning landscape of Ottawa or Gatineau.
Discovery
We begin by listening — to your vision, your site's potential, and your budget. Then we map every constraint: Ottawa's Official Plan or Gatineau's Plan d'urbanisme, zoning permissions, NCC design guidelines, heritage protections, and any required approval. Every limitation points toward a smarter design.
Strategy
Design is strategy. We translate your goals into schematic designs and 3D studies, then chart the most efficient path through the approval process — whether that's a straightforward permit or a Committee of Adjustment hearing with a strong evidentiary package.
Execution
From permit submission through construction administration — we manage drawings, coordinate with Ottawa Building or the Ville de Gatineau, conduct field reviews, and carry the project through to occupancy. You stay informed, never blindsided.
Your architect, wherever
you're building in the NCR.
From a heritage addition in the Glebe to a commercial fit-out in Gatineau's Hull sector to a garden suite in Barrhaven — 25:8 Architecture works across every neighbourhood in Ottawa and the Gatineau region.
Heritage permits, adaptive reuse, residential infill on tight lots, commercial interiors.
Victorian and wartime additions, mixed-use commercial, tech campus design, custom homes.
Multiplex conversions, custom homes, estate properties, community facilities.
New-build custom homes, suburban intensification, multi-unit residential.
Quebec building code expertise, riverfront properties, mixed-use and residential projects.
Rural and semi-rural custom homes, recreational properties, community buildings.
Not sure if we serve your area? We almost certainly do. Call us at (613) 276-8258.
Get a Free Estimate →Ready to build something
great in Ottawa or Gatineau?
Book a free 30-minute consultation. No obligation — just a clear, honest conversation about your project and what's possible.
Start your Ottawa or Gatineau
architecture project
Ottawa, ON K1R 5K4
Message sent!
We'll be in touch within 24 hours.
The architect who knows
both sides of the river.
For homeowners in the Glebe, developers building along Gatineau's Main Street, and businesses setting up in Kanata North here's why clients across the National Capital Region keep coming back to 25:8.
Ottawa's Official Plan, heritage designations, intensification corridors, Gatineau's Plan d'urbanisme we navigate both municipal frameworks daily. One firm, two cities, no surprises.
Heritage properties in Sandy Hill, tight infill in Hintonburg, riverfront sites in Gatineau, or large redevelopment parcels in Barrhaven give us a constrained site and we'll find the design that makes it work.
Ottawa's freeze-thaw cycles, OBC requirements, the National Capital Commission's design guidelines, and the region's mix of Victorian, postwar, and contemporary fabric we design from the inside out, for this specific place.
Not a junior drafter. Not a project coordinator. A licensed OAA architect on every call, every site visit, every permit submission. One point of contact, full professional accountability.
Recent projects
Ottawa & Gatineau projects Residential · Commercial · Multi-unit · Institutional
Full Portfolio at 258arch.com ↗Design is strategy.
Strategy is future.
Every 25:8 project follows a rigorous three-phase framework built around your site's specific opportunities, constraints, and the planning landscape of Ottawa or Gatineau.
Discovery
We begin by listening to your vision, your site's potential, and your budget. Then we map every constraint: Ottawa's Official Plan or Gatineau's Plan d'urbanisme, zoning permissions, NCC design guidelines, heritage protections, and any required approval. Every limitation points toward a smarter design.
Strategy
Design is strategy. We translate your goals into schematic designs and 3D studies, then chart the most efficient path through the approval process whether that's a straightforward permit or a Committee of Adjustment hearing with a strong evidentiary package.
Execution
From permit submission through construction administration we manage drawings, coordinate with Ottawa Building or the Ville de Gatineau, conduct field reviews, and carry the project through to occupancy. You stay informed, never blindsided.
Your architect, wherever
you're building in the NCR.
From a heritage addition in the Glebe to a commercial fit-out in Gatineau's Hull sector to a garden suite in Barrhaven 25:8 Architecture works across every neighbourhood in Ottawa and the Gatineau region.
Heritage permits, adaptive reuse, residential infill on tight lots, commercial interiors.
Victorian and wartime additions, mixed-use commercial, tech campus design, custom homes.
Multiplex conversions, custom homes, estate properties, community facilities.
New-build custom homes, suburban intensification, multi-unit residential.
Quebec building code expertise, riverfront properties, mixed-use and residential projects.
Rural and semi-rural custom homes, recreational properties, community buildings.
Not sure if we serve your area? We almost certainly do. Call us at (613) 276-8258.
Get a Free Estimate →Ready to build something
great in Ottawa or Gatineau?
Book a free 30-minute consultation. No obligation just a clear, honest conversation about your project and what's possible.
Start your Ottawa or Gatineau
architecture project
Ottawa, ON K1R 5K4
Message sent!
We'll be in touch within 24 hours.
Ready to Build Affordable Housing in Ottawa?
Whether you have a plot, a plan, or just an idea — our team can guide you through every step. Let's create something meaningful and cost-effective together.
Book a ConsultationDesigning Tomorrow Today: 25 Hours: 8 Days a Week
642 Somerset St W,
Ottawa, ON K1R 5K4
(613) 276-8258
info@258arch.com
