We added a three-season sunroom to the back of our Burlington two-storey last summer. It replaced a deteriorated deck and gave us usable outdoor living space from April through October. Full cost and permit experience below.
What we built:
- 14x22 ft (308 sq ft) three-season room off the back of the main floor
- Aluminum frame, Low-E glass on three walls and roof
- Tiled concrete floor with in-floor heating (electric mat — runs rarely, just to take the chill off in May/October)
- Ceiling fan, 4 exterior-grade pot lights
- Double door entry from dining room
- Screen panels that replace glass sections in summer
Permit:
Burlington requires a permit for any permanent attached structure. I was surprised — I assumed three-season rooms might be exempt. They’re not.
- Building permit: $680
- Timeline: 3 weeks to issuance
- Inspections: footing, framing, final
Quotes:
- TEMO prefab dealer: $42,000 installed (their product, their crew)
- Custom aluminum/glass contractor A: $52,000
- Custom aluminum/glass contractor B: $47,500
- Local carpenter + glazing subcontractor: $38,000
We went with the TEMO dealer — the 10-year product warranty and the single-contractor accountability were worth the slight premium over the local carpenter quote.
Final cost with permit and floor heating: $43,800
Results after one full year:
We used the sunroom 7 months of the year. The floor heating was used exactly 8 times — just enough to make it comfortable on cold spring mornings. The space has completely replaced our backyard deck usage for morning coffee and evening dinners April through October.