How Much Does It Cost to Build a Deck in 2026?

Building a deck in Ontario typically costs $35 to $120 per square foot installed, depending on size, materials, height, and design features. For many homeowners in Newmarket, this means total project costs usually fall between $8,000 and $30,000 for a standard backyard deck.

However, the final price rarely depends on size alone. Material choices, deck height, local building codes, and labour all influence the cost. Homeowners also consider upgrades such as railings, lighting, or pergolas to improve the outdoor living space. Understanding these factors helps you plan a realistic budget before construction begins. 

Read on to learn what truly affects deck pricing and how to estimate your project cost.

How Much Does it Cost to Build a Deck?

In Ontario, homeowners usually pay $35 to $120 per square foot installed. So, how much does it cost to build a deck? Most Newmarket projects range from $8,000 to $30,000, depending on size, materials, and structural complexity.

Price doesn’t depend on size alone. The materials you choose can make a big difference in overall cost. For example, pressure-treated lumber is more budget-friendly upfront, while composite decking costs more initially but helps reduce maintenance over time.

Deck height also plays a role. Ground-level decks are simpler to build, using basic footings and framing. Elevated decks, on the other hand, require stronger support, deeper concrete footings, and proper safety railings.

Local building codes in Ontario also call for guardrails and solid structural support. These guidelines are there to keep your deck safe and long-lasting. That’s why many homeowners in Newmarket prefer working with professionals for deck design and installation.

Cost to Build a Deck by Size

Deck size strongly influences the total deck building cost. In Ontario, smaller decks usually cost $4,000 to $8,000, while mid-sized decks range from $10,000 to $25,000. Large backyard decks often reach $30,000 or more, depending on structure, materials, and design.

However, size changes the project in several ways. Larger decks require longer beams, stronger joists, and more concrete footings. They also need additional railings and stairs. As a result, both labour and materials increase as the structure expands. Many Newmarket homeowners plan the deck size carefully before construction.

Some homeowners work with professionals through deck layout and installation planning to design a deck that fits the backyard and budget.

Here is the detailed cost breakdown table you should know about: 

Deck Size	Average Costs to Build a Deck	Common Use
10×10 Deck	$4,000 – $8,000	Small seating area or BBQ space
12×12 Deck	$6,000 – $12,000	Patio extension for small families
16×20 Deck	$12,000 – $25,000	Outdoor dining and entertaining
20×20 Deck	$20,000 – $40,000+	Large backyard living space

Costs to build a deck per square foot

In Newmarket and across Ontario, the deck cost per square foot typically ranges from $35 to $120 installed. Pressure-treated wood costs less, while composite or hardwood decking increases price due to higher material and installation costs.

Square Footage	Pressure-Treated Wood Deck	Cedar / Hardwood Deck	Composite Deck
80 sq ft	$2,800 – $4,000	$4,000 – $5,800	$5,600 – $7,200
100 sq ft	$3,500 – $5,000	$5,000 – $7,200	$7,000 – $9,000
120 sq ft	$4,200 – $6,000	$6,000 – $8,600	$8,400 – $10,800
144 sq ft	$5,000 – $7,200	$7,200 – $10,400	$10,000 – $13,000
200 sq ft	$7,000 – $10,000	$10,000 – $14,000	$14,000 – $18,000
256 sq ft	$9,000 – $12,800	$12,800 – $18,000	$18,000 – $23,000
400 sq ft	$14,000 – $20,000	$20,000 – $28,000	$28,000 – $36,000

Note: 

These estimates include framing, decking boards, and basic guardrails. However, upgrades such as lighting, pergolas, or waterproofing increase pricing. For example, homeowners adding composite decking typically pay more upfront but reduce long-term maintenance costs.

Top Factors That Affect Your Deck Cost

Several factors affect the final deck builder cost in Newmarket. The most important include deck size, materials, structure height, labour, permits, and added features. Each element changes the total average cost to build a deck.

Deck Height and Structural Complexity

Deck height significantly changes the structure and the total deck framing cost. Ground decks sit close to the yard, so they need simpler footings and framing. Raised decks, however, must support greater weight and meet stricter Ontario safety rules.

In many Newmarket homes, especially those with walkout basements, decks often sit several feet above grade. This height requires stronger beams, properly spaced joists, and deeper concrete footings to handle Ontario’s freeze-thaw cycles.

Deck Type	Structural Needs	Cost Impact
Ground Deck	basic framing and shallow footings	lowest cost
Raised Deck	beams, joists, guardrails	moderate cost
Second-Story Deck	engineered framing, tall railings	highest cost

Labour and Installation Costs

In Newmarket and across York Region, labour usually costs $20–$45 per square foot. This forms a large part of the deck installation cost. Skilled crews prepare the site, pour concrete footings, install framing, and secure decking boards. They also build stairs and guardrails to meet Ontario safety codes.

For many homeowners, labour becomes the deciding factor in the cost to install a deck. A simple backyard deck installs faster and costs less. However, larger layouts, tight backyard access, or raised structures require more crew time. 

If an old deck already exists, builders may also need deck replacement and removal before construction begins.

Materials Selection 

Material choice strongly affects the final deck price. In Newmarket projects, homeowners often choose between pressure-treated wood, cedar, or composite decking. Each option changes durability, maintenance, and the overall cost to build a wood deck.

Deck Material	Average Installed Cost per sq ft	Maintenance Level	Lifespan
Pressure-Treated Wood	$35 – $55	Regular staining required	10–15 years
Cedar Wood	$50 – $75	Moderate maintenance	15–20 years
Composite Decking	$70 – $110	Very low maintenance	25–30+ years

Pressure-treated lumber remains the most budget-friendly option. However, cedar provides a natural appearance and stronger rot resistance. Meanwhile, many homeowners prefer composite decking because it lasts longer and requires minimal upkeep.

Custom Design Features

Custom features often increase the final deck price. Many Newmarket homeowners upgrade their decks to create a more comfortable outdoor space. These additions raise material use, labour time, and the overall deck builder cost.

Custom Feature	Typical Cost Range
Deck Lighting	$800 – $3,000
Built-In Benches	$1,000 – $2,500
Aluminum or Glass Railings	$120 – $250 per linear ft
Pergolas or Shade Structures	$3,000 – $10,000+
Waterproof Deck Systems	$3,000 – $12,000

For example, many homeowners add deck lighting installation to improve safety and evening use. In many projects we complete at XP Decking, homeowners also include pergolas or built-in seating to create a more functional backyard living space.

Local Codes and Permits

Before building a deck in Newmarket, check local permit rules. Under the Ontario Building Code, decks higher than 600 mm (about 24 inches) above ground usually require a building permit. 

For homeowners, this means submitting deck plans and scheduling inspections during construction. Permit fees typically range from $200 to $500, depending on deck size and structure. Following these rules helps avoid delays, fines, or costly rebuilds later.

Demolition and Removal

If your backyard already has an old deck, demolition becomes the first step. In Newmarket, the deck replacement cost for removal usually ranges from $500 to $2,500, depending on deck size, wood type, framing condition, and disposal fees. 

Crews must dismantle decking boards, joists, beams, and concrete footings safely before new construction begins. Many homeowners schedule deck replacement and removal to clear the structure, inspect the ground, and prepare proper footings for the new deck.

Season

Season affects both pricing and scheduling in Newmarket deck projects. Spring and early summer bring the highest demand because homeowners prepare outdoor spaces for warmer months. 

As a result, contractor schedules fill quickly, and labour rates may rise. Ontario’s winter frost also limits digging for concrete footings. Many homeowners, therefore, schedule builds in late summer or early fall when crews have better availability and weather conditions remain stable.

Practical Ways to Reduce the Cost of Building a Deck

Homeowners can reduce the cost of building a deck by choosing simpler designs, affordable materials, and efficient construction timing. Careful planning of deck size, materials, and upgrades helps control the average cost of composite decking installed and overall project budget.

• Choose pressure-treated lumber instead of composite to lower upfront material costs.
• Keep the deck ground-level to avoid deeper footings and structural beams.
• Limit custom features like pergolas, glass railings, or curved layouts.
• Build during late fall or early spring when contractor demand is lower.
• Keep deck size practical; larger layouts increase materials and labour quickly.
• Combine upgrades during construction to avoid future installation labour.
• Use durable materials that reduce long-term maintenance and repair costs.

DIY Deck vs Hiring a Professional Deck Builder

Building a deck yourself may save labour costs. However, hiring experienced deck builders in Newmarket, Ontario, often ensures safer construction, proper permits, and long-term durability. DIY projects reduce upfront cost, while professional installation reduces structural risks and costly repairs.

Evaluation Factor	DIY Deck Construction	Professional Deck Builder
Initial Investment	Lower upfront cost for labour	Higher upfront investment
Construction Quality	Depends on the homeowner’s skill and tools	Built by trained carpenters with industry experience
Building Permits & Code Compliance	Homeowners must manage permits and inspections	Contractor handles permits and Ontario Building Code compliance
Structural Design	Limited engineering knowledge	Proper joist spacing, beams, and footing design
Project Timeline	Often several weekends or months	Typically completed within days or weeks
Safety Standards	Higher risk of framing or railing errors	Built to professional safety standards
Long-Term Durability	Potential for repairs if mistakes occur	Better structural stability and longevity
Warranty & Support	No workmanship warranty	Many contractors provide workmanship guarantees

In Closing

Building a deck is a major investment, so careful planning makes a big difference. Beyond size and materials, homeowners should also consider long-term maintenance, drainage, and how the deck connects with the backyard layout. 

If you’re planning a new deck in Newmarket or nearby areas, getting expert advice early can help avoid costly design mistakes. At XP Decking, we help homeowners design and build decks that match their space, budget, and lifestyle. Contact XP Decking today to discuss your project and get a professional estimate for your custom deck.