Getting accurate quotes for your interlock paving project is crucial for proper budgeting and avoiding unexpected costs. Many homeowners are frustrated when they receive wildly different estimates from contractors, or worse, discover hidden costs after work has begun. The key to receiving precise, reliable quotes lies in the preparation work you do before contacting contractors.
In this comprehensive guide, we’ll walk you through exactly what professional contractors need to provide you with accurate estimates, how to prepare your space for assessment, and the red flags to watch for when comparing quotes.
Why Accurate Quotes Matter
An accurate quote protects both you and your contractor. For homeowners, it provides a realistic budget framework and prevents the shock of cost overruns mid-project. For contractors, detailed information allows them to allocate proper resources, schedule effectively, and avoid disputes about “unforeseen” circumstances that were actually visible from the start.
According to industry data, projects with thorough initial assessments are 60% less likely to experience budget overruns and 40% more likely to finish on schedule. The investment of time upfront pays dividends throughout your entire project.
Essential Photos Contractors Need
High-quality photos are the foundation of remote estimates and help contractors prepare for in-person assessments. Here’s what you should document:
Current Surface Condition
Take multiple photos of your existing driveway, patio, or walkway from different angles. Capture the entire area in wide shots, then take close-ups of any problem areas like cracks, settling, or drainage issues. If you’re replacing an existing surface, contractors need to assess demolition requirements and disposal costs.
For new installations, photograph the current ground condition. Is it grass, gravel, or bare earth? The existing substrate affects excavation depth and base preparation requirements, which significantly impact pricing.
Access Points and Pathways
Contractors need to know how equipment and materials will reach your project site. Take photos of:
- Your driveway entrance and street access
- Gate widths if equipment needs to pass through
- Side yards or pathways to backyard projects
- Any obstacles like mature trees, air conditioners, or utility boxes
- Overhead clearances such as power lines or tree canopies
Access limitations can increase labor costs by 20-40% if equipment can’t be used and work must be done manually. Being upfront about access challenges ensures contractors factor this into their estimates rather than discovering it on day one.
Utilities and Infrastructure
Document the location of visible utilities including:
- Electrical conduits and meter boxes
- Gas line access points
- Water shut-off valves
- Irrigation system components
- Drainage systems and downspouts
- Underground sprinkler heads
These elements may need to be worked around, temporarily relocated, or integrated into the new design. In Ottawa, contractors must call Ontario One Call before excavating, but your photos help them anticipate potential complications.
Drainage and Grading
Take photos showing how water currently flows across your property. After rainfall, document any pooling areas, drainage patterns toward or away from your foundation, and existing drainage solutions like French drains or catch basins.
Proper drainage is critical for interlock longevity. Projects requiring extensive grading corrections or drainage system installation will cost more than simple installations on properly-sloped terrain.
How to Measure Your Space
Accurate measurements are essential for precise material calculations and cost estimates. Here’s how to measure different project types:
Rectangular Areas
For driveways, patios, and walkways with straight edges:
- Measure the length and width in feet
- Multiply to get square footage (Length × Width = Square Feet)
- Add 5-10% for cuts and waste
For example, a 20-foot by 30-foot driveway is 600 square feet. Adding 8% for waste brings your material requirement to approximately 648 square feet.
Irregular Shapes
For curved patios or uniquely shaped areas:
- Divide the space into simpler shapes (rectangles, triangles, circles)
- Measure each section individually
- Calculate area for each section using appropriate formulas
- Add all sections together
- Add 10-15% for irregular shapes due to increased cutting requirements
If mathematics isn’t your strong suit, sketch the area on graph paper with each square representing one foot. Count the squares for a reasonable approximation.
Multi-Level Projects
For stepped patios or terraced areas, measure each level separately and note the height difference between levels. Retaining walls, steps, and grade changes add significant complexity and cost.
Using Our Price Calculator
Once you have measurements, use our interlocking price calculator to get ballpark estimates. While not a replacement for professional quotes, it helps you understand the general cost range for your project size. For more detailed pricing information, check our pricing guide and our comprehensive breakdown in Interlock Driveway Cost Ottawa 2026.
Access Considerations That Affect Price
Access is one of the most significant cost variables in interlock projects. Here’s what contractors evaluate:
Equipment Access
Can a skid steer, plate compactor, or delivery truck reach your project area? Projects requiring wheelbarrow-only access can increase labor costs by 30-50%. Narrow side yards (less than 4 feet wide) typically prevent equipment passage.
Measure gate openings and pathway widths. Standard equipment requires 36-48 inches of clearance. If you have a locked gate or removable fence section, mention this in your quote request.
Material Staging Area
Contractors need space to stage pallets of pavers, sand, gravel, and equipment. A typical driveway project requires staging area equivalent to about one parking space. If materials must be stored on the street, permits may be required in some Ottawa neighbourhoods, adding administrative costs.
Disposal Access
Removal projects require bin access. Can a disposal bin be placed on your driveway, or must it go on the street? Street placement often requires municipal permits (around $100-200 in Ottawa) and may have time restrictions.
Distance from Street
Backyard projects 100+ feet from material drop-off points increase labor for material hauling. Long distances from the work area to disposal bins also add time and cost.
Information That Improves Quote Accuracy
Beyond photos and measurements, providing this additional information helps contractors give more precise estimates:
Project Timeline and Flexibility
Are you flexible on timing or do you need work completed by a specific date? Projects scheduled during peak season (May-September in Ottawa) may have premium pricing. Late-season or early-season projects might offer better rates.
Existing Conditions
- Age of current installation (if replacing)
- Known foundation or drainage issues
- Soil type (clay, sand, loam) if known
- Previous settling or movement problems
- Tree roots that may affect excavation
Design Preferences
While contractors can guide you, having initial ideas helps with estimating:
- Paver style preferences (standard, permeable, designer pavers)
- Pattern complexity (running bond vs. herringbone vs. custom)
- Border or accent color requirements
- Additional features (steps, retaining walls, lighting)
Complex patterns require more cutting and skilled labor, increasing costs by 15-25% compared to simple running bond patterns.
Property Details
- Homeowner association restrictions or requirements
- Municipal permit requirements
- Easements or property line considerations
- Setback requirements from property boundaries
Red Flags in Quotes to Watch For
Not all quotes are created equal. Here are warning signs of problematic estimates:
Unusually Low Prices
If one quote is 30%+ below others, investigate why. Common corners cut include:
- Inadequate base depth (should be 8-10 inches minimum in Ottawa’s freeze-thaw climate)
- Poor quality or insufficient bedding sand
- Skipping proper compaction steps
- No edge restraint system
- Unlicensed or uninsured labor
Quality interlock installation has industry-standard requirements that cost a certain amount to do correctly. Dramatically low prices usually mean something essential is being omitted.
Vague Scope Descriptions
Quality quotes specify:
- Excavation depth
- Type and depth of base material (crushed limestone is standard)
- Bedding sand type and depth
- Paver brand, style, and color
- Edge restraint method
- Compaction equipment and process
- Polymeric sand or standard joint sand
Quotes saying simply “install interlock patio” without these details leave room for substandard materials or methods.
No Written Warranty
Reputable contractors provide written warranties covering:
- Workmanship (typically 2-5 years)
- Settling or movement issues
- Drainage problems
- Material defects (backed by manufacturer warranty)
Verbal promises without written warranties are red flags.
Pressure for Immediate Decision
Be wary of “today only” pricing or pressure to sign immediately. Professional contractors understand you need time to compare options and make informed decisions.
Cash-Only Discounts
Significant discounts for cash payments often indicate tax avoidance, which may also mean no WSIB coverage or liability insurance. If something goes wrong, you could be held liable.
No Insurance Proof
Always request proof of:
- Liability insurance ($1 million minimum recommended)
- WSIB coverage
- Business registration
Contractors resistant to providing this documentation pose serious risk to homeowners.
Large Upfront Deposits
Standard industry practice is 10-25% deposit with remaining payment due upon completion. Requests for 50%+ upfront, especially before materials are ordered, are warning signs. Never pay in full before work is completed.
Preparing for In-Person Estimates
Even with excellent photos and measurements, most contractors will want to visit the site. Here’s how to prepare:
Clear the Area
Remove vehicles, toys, furniture, and other items from the project area so contractors can clearly see the space and take their own measurements.
Unlock Access
Ensure gates are unlocked and contractors can access all relevant areas including side yards and backyards.
Prepare Questions
Have your questions written down:
- Timeline and scheduling
- Warranty details
- Payment schedule
- Change order process
- How they handle unexpected issues
- Site cleanup and disposal
- References from recent projects
Discuss Utilities
Show contractors where utilities enter your property. Discuss who handles Ontario One Call requests (typically the contractor, but confirm).
Talk About Concerns
Be upfront about any concerns like drainage problems, settling history, or budget constraints. Good contractors will address these honestly rather than glossing over potential issues.
Comparing Multiple Quotes
Once you receive quotes, compare apples to apples:
- Are base depths the same?
- Same quality of pavers and materials?
- Similar warranties?
- Comparable timelines?
- What’s included vs. excluded?
The cheapest quote is rarely the best value. Look for contractors who:
- Communicate clearly and professionally
- Provide detailed written quotes
- Show proof of insurance and credentials
- Have strong references and portfolio
- Explain their process and materials thoroughly
- Stand behind their work with real warranties
Ready to Get Your Accurate Quote?
Now that you know exactly what contractors need for precise estimates, you’re ready to start gathering quotes for your interlock project. Take comprehensive photos, measure carefully, document access considerations, and compile the information covered in this guide.
At Interlock Experts, we provide detailed, transparent quotes based on thorough site assessment. We’ll walk you through every aspect of your project, explain material and labor costs clearly, and ensure you have realistic expectations from the start.
Get started today: Contact us for your free, no-obligation quote. Include photos and measurements using this guide, and we’ll provide you with a detailed estimate for your interlock driveway, patio, walkway, or outdoor living space.
Our experienced team serves all of Ottawa and surrounding areas, bringing over a decade of expertise to every project. We’re committed to transparent pricing, quality workmanship, and customer satisfaction from quote to completion.