Legal Basement Apartment Markham: 2026 Cost & Process Guide
Legal basement apartments in Markham cost $85,000 – $300,000+ depending on whether underpinning and a separate exterior entrance are required. Compliance is mandatory across three regimes: zoning, Ontario Building Code Part 9, and Ontario Fire Code Section 9.8. Done right, a one-bedroom legal suite generates $1,800 – $2,400/month rent and adds $180,000 – $240,000 to resale value. Country Renovations works across Markham including Unionville, Cornell, Cathedraltown, Berczy Village, Box Grove, Markham Village, Thornhill (Markham side) — with City of Markham permit experience and the HCRA + Tarion compliance stack required for new builds and substantial additions.
Why Country Renovations. Building across Toronto and the GTA — including Markham — since 2014. HCRA-registered, Tarion-enrolled for qualifying projects, WSIB-cleared, $5M general liability insured. Free written fixed-price quote in 5 business days. Book a free site visit →
Key Takeaways for Markham Homeowners
- Entry / Good tier: $89,250 – $133,875
- Mid-range tier: $133,875 – $181,125
- Premium tier: $220,500 – $315,000+
- City of Markham plan review: 20 business days service standard for residential permits
- Markham market tier: premium
Legal Basement Apartment Services in Markham
- Zoning compliance check (lot size, setbacks, parking)
- Ontario Building Code Part 9 — ceiling height (1.95 m), egress windows, fire separation (30-min)
- Ontario Fire Code Section 9.8 — interconnected smoke alarms, CO alarms, fire-rated doors
- Sound separation STC 50 between units
- Separate exterior entrance with engineered stairwell
- Underpinning to gain ceiling height ($400 – $700/sq ft)
- Multi-Tenant House Registration with municipality
- Annual fire inspection (where required by municipality)
Markham Permit & Process Reality
Markham balances heritage areas (Unionville, Markham Village — heritage permits sometimes apply) with newer subdivisions (Cornell, Cathedraltown, Berczy Village).
Legal basement apartment permits in Markham require building permit + plumbing/electrical permits + ESA notification + fire safety plan + second-suite registration with the municipality.
For second-suite specifics: second suites are permitted as-of-right post-Bill 23 with a Markham registration program and parking review. Country Renovations pulls all permits on your behalf — including stamped drawings, structural engineering letters where required, and the AST or municipal portal submission.
Markham Legal Basement Apartment Cost Table (2026 CAD)
| Tier | Total Cost (CAD 2026) | Markham Notes |
|---|---|---|
| Good / Entry | $89,250 – $133,875 | Code-minimum scope; standard materials |
| Better / Mid-Range | $133,875 – $181,125 | Full scope, mid-range materials, common in Markham |
| Best / Premium | $220,500 – $315,000+ | Custom finishes, structural changes where applicable |
The Country Renovations Process in Markham
- Free Site Visit (Day 1). Measure space, assess existing conditions, discuss scope at no charge.
- Written Fixed-Price Quote (within 5 business days). Line-itemed proposal — materials, labour, permits, contingency, timeline.
- Design & Selections. Floor plans, finish selections, 3D renderings for premium projects.
- Permits & Engineering. City of Markham permit submission, structural engineering if required, ESA filing, TSSA for gas.
- Build. Daily check-ins with your project manager. Single accountable point of contact throughout.
- Final Inspection & Handover. Building inspection, ESA pass certificate, complete site clean.
Frequently Asked Questions — Legal Basement Apartment Markham
How much does a legal basement apartment cost in Markham in 2026?
A code-minimum legal basement apartment in Markham costs $85,000 – $130,000. Mid-range build $150,000 – $200,000. With underpinning and a separate exterior entrance: $250,000 – $300,000+ for an 800–1,000 sq ft one-bedroom suite.
Are basement apartments legal in Markham?
Yes — second suites are permitted as-of-right post-Bill 23 with a Markham registration program and parking review. Compliance with Ontario Building Code Part 9 and Ontario Fire Code Section 9.8 is mandatory regardless of municipality.
What is the rental income on a legal basement apartment in Markham?
A one-bedroom legal basement apartment in the premium Markham market rents for approximately $1,800 – $2,400/month in 2026. Net annual income (after utilities split, insurance delta, maintenance reserve) is typically $18,000 – $25,000.
Get a Free Quote in Markham
Country Renovations has been delivering legal basement apartment projects across Markham and the GTA since 2014. HCRA-registered. Tarion-enrolled for qualifying projects. WSIB-cleared. $5M insured. Book a free site visit and you’ll receive a written, fixed-price quote with credentials attached in 5 business days.