Construction Estimating
Know what your renovation will actually cost before you start
Written by Pavel Vysotckii
BCIN-certified building designer & Quantity Surveyor · Updated June 2026
Project Overview
Fixed Milestone Pricing
You approve each stage before it's paid
What is construction estimating?
Construction estimating is the process of calculating the total cost to complete a renovation project. An estimator measures the work (takeoff), prices materials at current rates, calculates labour hours based on productivity standards, adds equipment and subcontractor costs, then applies overhead, profit, and contingency.
Estimates come in three levels of accuracy. A rough order of magnitude (ROM) estimate uses $/sq ft averages and comes within ±30-50% — good enough to know if a project is $50K or $150K. A preliminary estimate uses approximate quantities and comes within ±15-25% — used for budget approval and financing applications. A detailed estimate includes full material takeoffs, firm subcontractor quotes, and specific labour hours, accurate to ±5-10%.
Most homeowners get confused when three contractors submit quotes that differ by 30% or more. This usually means different scopes — one quote includes asbestos abatement, another assumes you'll handle permits, a third forgot to price the structural beam. A good estimate lists every assumption and exclusion.
Ontario residential estimating uses unit costs: framing runs $8-$15/sq ft, drywall $3-$6/sq ft (supply and install), interior painting $2-$5/sq ft, hardwood flooring $8-$15/sq ft installed. Plumbing rough-in for a new bathroom costs $3,000-$6,000. Electrical rough-in runs $4-$8/sq ft. These are 2026 GTA rates — adjust down 10-15% outside the Golden Horseshoe.
Contingency is the money set aside for unknowns. Use 10% for new construction or well-defined scope, 15-20% for renovations in homes built before 1980, and 25%+ for heritage homes or projects with structural unknowns. Homeowners who skip contingency always regret it when they open a wall and find knob-and-tube wiring or a rotted sill plate.
When you need construction estimating
- Before you apply for a home equity line of credit or construction mortgage
- When comparing contractor quotes that differ by more than 20%
- For insurance claims or damage assessments that require documented costs
- Before you commit to a fixed-price contract with a general contractor
- When planning a multi-phase renovation and need to prioritize scope
- For development pro formas or investment property feasibility studies
- When a contractor's quote seems too low and you suspect missing scope
The Process
What happens from start to finish
Scope Definition
1-2 daysDefine exactly what work is included and excluded. List all finishes, fixtures, and quality levels. Identify who handles permits, demolition, and disposal. Clear scope prevents change orders.
Site Visit & Measurement
2-4 hoursWalk the site, take measurements, photograph existing conditions. Check for access constraints, hazardous materials, structural issues. Measure twice, estimate once.
Material Takeoff
1-3 daysCalculate quantities for every material: studs, drywall sheets, linear feet of trim, fixture counts. Use architectural drawings if available, field measurements otherwise. Round up to account for waste.
Labour Pricing
1-2 daysEstimate hours for each trade using productivity rates. Framing: 1-2 hours per sq ft for walls. Drywall: 15-20 sheets per day per installer. Apply hourly rates: $45-$75 for carpenters, $65-$95 for licensed electricians.
Subcontractor Quotes
3-7 daysGet firm quotes from HVAC, plumbing, electrical, roofing subs. Verbal quotes expire in 30 days. Written quotes should lock pricing for 60-90 days.
Overhead & Profit
1 dayAdd contractor overhead (10-15% to cover office, insurance, vehicles, WSIB) and profit (8-15%). This is normal — contractors aren't charities.
Contingency & Final Review
1 dayAdd contingency based on project risk. Review for missing items: permits ($1,200-$3,000), bin rental ($400-$800/week), temporary services. Add 13% HST to the total.
Investment Guide
Professional estimating fees depend on project complexity and level of detail required. Many general contractors include estimating as part of their proposal process.
Rough Order of Magnitude (ROM)
$0-$300
Depends on: Quick $/sq ft calculation, no site visit, ±30-50% accuracy. Many contractors do this for free during initial consultation.
Preliminary Estimate
$300-$800
Depends on: Site visit, approximate quantities, subcontractor budgets, ±15-25% accuracy. Used for financing applications and budget approval.
Detailed Estimate
$800-$2,500
Depends on: Full material takeoff, firm subcontractor quotes, labour hour breakdown, ±5-10% accuracy. Required for fixed-price contracts and cost-plus with GMP (guaranteed maximum price).
Large Commercial or Complex Residential
$2,500-$10,000+
Depends on: Multi-trade coordination, engineered systems, value engineering, CPM scheduling integration. Typically 0.5-1% of estimated construction cost.
What Affects the Price
Get an accurate estimate before you commit. Book a free walkthrough for line-item pricing.
Get a ballpark estimate in under 2 minutes.
Fixed Milestone Pricing, Approved by You
Every construction estimating project runs on fixed milestone pricing. The plan is signed before work starts, and you approve each stage before it's paid.
Plan Signed Before Work Starts
Every milestone and its price is written into the contract up front — no surprise extras.
Review in the Live App
Daily photos, inspection reports, and spend vs budget land in your client app at every phase.
You Approve Each Milestone
A stage is only paid after you review the work and sign off in the app.
Project Center
Construction Estimating
Milestone Progress
Milestone 3 of 4
Common Estimating Mistakes
- Comparing quotes with different scopes — one includes demolition and permits, another assumes you handle it
- No contingency — every renovation uncovers something. Budget 15-20% extra for homes built before 1980
- Forgetting HST — add 13% to all costs unless contractor quotes say "plus HST"
- Using $/sq ft without understanding what's included — does it cover mechanical, finishes, permits, design fees?
- Ignoring escalation — material and labour costs change. Lock in pricing with firm quotes, not estimates from 6 months ago
- Underestimating demolition and disposal — demo often costs 10-15% of total construction budget
- Missing soft costs — permits, architectural fees, engineering, hydro/gas connections, insurance, financing costs add 8-15%
- Assuming DIY labour is free — your time has value, and mistakes cost money to fix
Trusted by Ontario Homeowners
One licensed crew and a live client app on every construction estimating project
Licensed
OBC Licensed, Insured & WSIB Covered
Live App
Daily Photos & Inspection Reports
Fixed Price
Milestones You Approve
Related Services
General Contractor
GCs provide estimates as part of their proposal process and manage all trades to keep the project on budget
Learn moreProject Management
Project managers track actual costs against estimates and issue change orders when scope changes
Learn moreArchitectural Drafting
Detailed drawings improve estimate accuracy by 15-25% and reduce change orders during construction
Learn moreBuilding Permit
Permit fees and review timelines should be included in every renovation estimate
Learn moreCommon Questions
How accurate is a renovation estimate?
What's a contingency and how much should I budget?
Why are quotes from three contractors so different?
Should I always get three quotes?
What's a material takeoff?
Can I estimate renovation costs myself?
What does cost-per-square-foot actually mean?
Why do older homes cost more to renovate?
Where we do this work
Based in Toronto, working across the GTA
Ready to start your construction estimating project?
One crew, one fixed plan, and the live app on every construction estimating project. Daily photos, inspection reports, milestone pricing you approve — and a written warranty.