"Working with James was great from the beginning. He put my mind at ease with his product knowledge and his creative designs."
Outdoor Luxury · Oakville, GTA
Outdoor Living Spaces in Oakville.
Astonia Landscaping designs and builds high-end residential landscapes and natural-stone masonry for homeowners in Oakville. Owner James Dennison is a third-generation stonemason, and the firm has worked across the GTA and Durham Region since 1975. Every project is owner-led, with daily communication from the first consultation through the last stone set in place.
- Since 1975
- 3 Generations
- $5M Insured
- WSIB Covered
- Unilock Authorized
In Oakville
Landscaping that belongs in Oakville.
Oakville rewards patience. Many of its finest properties sit on generous, mature lots in Old Oakville and along the lakeshore, where established gardens, decades-old trees, and stone walls already give the land its character. Building well here means working with what is already there rather than clearing it away. We design around the trees worth keeping, match new masonry to the weight and tone the street already carries, and treat the existing garden as a starting point, not an obstacle. The result should look like it has always belonged.
Homeowners in this part of Halton tend to be design-led, and they have usually lived with their property long enough to know exactly what is missing. They notice how a stone wall is coursed, how a step meets a path, how a terrace sits against the house. That kind of attention is the reason we work the way we do. As a third-generation stonemason, James handles the natural-stone work and the design intent personally, and because Astonia owns its own equipment and hauls every bit of debris away in its own trucks, the property stays calm and orderly through a build that may run many months.
The lakeside setting brings real site considerations. Lots closer to the shore deal with grade changes, drainage, and mature root systems that all have to be read carefully before anything is built, and established neighbourhoods often mean tight access and close neighbours who would rather not see a bin sitting at the curb for a season. Astonia is fully WSIB-covered and carries $5M in liability insurance, and as a Unilock Authorized Contractor we hold our hardscape work to a standard meant to last in this climate. The aim on every Oakville property is craft that settles into the place and looks better with age.
What we build
Outdoor Living Spaces, start to finish.
Outdoor Kitchens
Fireplaces & Fire Pits
Pergolas & Pavilions
Landscape Lighting
Outdoor Living Rooms
Stone Fire Features
The craft
Built from the ground down.
An outdoor living space is the part of a property a family actually uses — so we build it to the same standard as the rooms inside the house. The work spans outdoor kitchens, fireplaces and fire pits, pergolas and pavilions, full landscape lighting, and the seating, dining and lounging areas that tie them into one place you can spend an evening. Everything is designed as a single composition, anchored in natural stone, and laid out so the cooking, the fire and the gathering all face the same direction — toward the people you built it for.
The masonry is where this work earns its place. James is a third-generation stonemason, and the kitchens and fireplaces are built the way a chimney is — proper footings below the frost line, a structural core, and a hand-laid natural-stone face rather than a veneer pinned to a box. Outdoor kitchens are framed for the equipment they'll carry, with stone counters, weather-rated cabinetry and the gas, water and drainage run in before the first stone is set. Fireplaces and fire pits are built to draw and vent correctly, sized to the space so the heat reaches the seating instead of climbing straight up. Pergolas and pavilions are set on real foundations to hold their line through Ontario winters, season after season.
Lighting is treated as part of the build, not an afterthought wired in at the end. We layer it — low light washing the stone, soft fill at the steps and paths, a warmer pool over the dining and fire areas — so the space stays usable and beautiful well after dark, through three seasons of the year. The result is one continuous outdoor room: a place to cook, eat by the fire and stay outside longer than you planned, designed and built by one crew so the kitchen, the hardscape, the lighting and the planting around them all read as a single, deliberate whole.
Because Astonia owns its own equipment and hauls every bit of debris away in its own trucks, a build of this scale moves on its schedule, not a subcontractor's — and your property stays clear, with no rented bin parked on the drive for weeks. James runs the project himself and stays in daily contact from the first layout to the final light being aimed. Crews are WSIB-covered and the company carries $5M in liability insurance, and as a Unilock Authorized Contractor we build to a standard that's independently backed. It's a serious, once-in-a-generation investment, and we treat it that way from the day the stone arrives to the night you first light the fire.
How it works
From first handshake to final reveal.
01
Initial Consultation
We meet you on-site to walk the space, understand how you want to live in it, and talk through your vision and investment — no obligation.
02
Design & 3D Review
Our designer measures and plans your space, then renders it in 3D so you can see it before we break ground. We refine every detail together.
03
Breaking Ground
Our own crews and equipment start at 7:00 AM, keep the site clean every day, and brief you each morning and evening — no subcontractor gaps, no bins.
04
Project Completion
After a final walkthrough, the only thing left behind is your finished space — built to gather on for generations.
The Astonia difference
Why homeowners in Oakville choose us.
Owner-led
Daily communication from James, from the first handshake to the final reveal.
Our own equipment
Small and heavy machines, run by our own crews — no subcontractor delays.
No unsightly bins
We haul every bit of debris away in our own trucks, every day.
$5M insured
Liability coverage above the industry average, for your peace of mind.
WSIB covered
A fully covered, professional crew on every project.
Unilock Authorized
Warranty-grade materials and professional installation standards.
Kind Words
Homeowners across the GTA, on the Astonia experience.
Five decades of referrals across the GTA & Durham — and a Unilock Authorized Contractor. Read more on Google & Houzz.
"The natural stone work and landscape job that James and his crew did is beautiful, outstanding work. The quality is outstanding — we would recommend this company to anyone."
"Astonia was a delight from start to finish. The crew showed up early and worked long days to finish on time. We are now enjoying the most amazing front yard. Outstanding results!"
"As a repeat client, we selected Astonia to transform our simple backyard into a relaxing space amongst a natural setting that will bring us many years of pleasure."
Good to know
Outdoor Living Spaces in Oakville, answered.
Yes. The masonry is built for Ontario winters on footings set below the frost line, and the fireplaces and fire pits are sized and vented to throw heat toward the seating — so the space stays comfortable well into the shoulder seasons. With the lighting layered in, most clients use these areas three seasons of the year rather than just the warm weeks of summer.
We plan and coordinate all of it as part of the build — the gas line for the cooking and fire features, water and drainage for the kitchen, and the wiring for layered landscape lighting — and it's run in before the stonework goes up. Because one crew designs and builds the whole space, the services are roughed in at the right stage instead of being retrofitted later, and licensed trades are brought in where the work calls for them.
We design and build across the GTA & Durham region — including Toronto, Etobicoke, Mississauga, Brampton, Oakville, Vaughan, Markham, Newmarket, Aurora, King City, Whitby, Oshawa, Bowmanville and the surrounding areas.
Every project is different — from focused stonework to a full landscape transformation — so we provide a clear, detailed proposal after an on-site consultation rather than a generic price. Most of our work is a meaningful, lasting investment in your property.
Timelines depend on scope, and you receive a realistic one at the design-review stage before we break ground. Because we own our equipment and run our own crews, we work efficiently — starting at 7:00 AM and keeping the site clean every day.
Yes. We carry $5 million in liability insurance — above the industry average — our crews are fully WSIB covered, and we are a Unilock Authorized Contractor.
More services in Oakville
Outdoor Living Spaces nearby
Outdoor Living Spaces in Oakville, done right.
Book a free on-site consultation. We design, build and plant the whole space — then haul it all away when the last stone is set.
$5M insured · WSIB-covered crews · 3rd-generation craftsmanship since 1975