Sunrooms and three-season porches
A three-season porch is the single best value-per-dollar addition on a Minnesota house. You get real usable square footage from April through October at a fraction of the cost of a conditioned addition — no HVAC extension, no full foundation in most cases, far simpler permitting.
What we build
- Three-season porches — insulated roof, screened or glass panels, unheated; usable roughly April to October
- Four-season sunrooms — fully insulated, heated and conditioned, counts as living space
- Screen porch conversions — adding glass panel systems to an existing screen porch
- Deck-to-porch conversions — roofing over an existing deck and enclosing it
- Under-deck and patio enclosures
- Motorized screen systems for large openings
Three-season vs four-season
| Three-season | Four-season | |
|---|---|---|
| Usable months | ~7 | 12 |
| Heating and cooling | None or space heater | Tied into HVAC or mini-split |
| Insulated walls and floor | Roof only, typically | Full |
| Counts as finished sq ft | No | Yes |
| Foundation | Often footings/piers | Frost footings required |
| Cost | Much lower | Roughly double |
Most homeowners who "want a sunroom" are actually happiest with a three-season porch plus a mini-split, which gets close to year-round use at three-season pricing.
Planning ranges (Twin Cities, estimates)
| Project | Typical range |
|---|---|
| Screen porch on existing deck | $18,000 – $35,000 |
| Three-season porch, new build | $28,000 – $60,000 |
| Four-season sunroom | $50,000 – $110,000 |
| Adding a mini-split | $3,500 – $6,500 |
| Motorized screen system | $4,000 – $12,000 |
Estimates for planning; foundation type, roof tie-in, and glass package drive the range.
Minnesota specifics
Frost footings go 42 inches deep in most of the metro. Roof structure has to carry the local snow load, which means a bigger header at the tie-in than people expect. Any conditioned four-season space triggers energy code requirements for insulation and window U-factor. All of that is permitted work, and we handle it.
What's included
- Free, no-pressure estimate
- Licensed & fully insured crew
- Cleanup included — we leave it spotless
- Same-day or scheduled service
- Written quote, fair pricing
- 24/7 emergency response
FAQ
Does a sunroom add to my home value?
A well-built four-season sunroom generally returns a meaningful share of its cost at resale and adds to finished square footage. A three-season porch does not count as finished square footage but is a strong selling feature in Minnesota.
Can I build a porch on my existing deck?
Often yes, but only if the footings and framing can carry a roof and walls. Most decks were sized for deck loads only, so the footings usually need reinforcement or replacement.
Can a three-season porch be used in winter?
With an insulated roof and a mini-split, many are comfortable well into December and again in March. Truly year-round use means insulated walls and floor — a four-season build.
How long does it take?
A screen porch on an existing structure is roughly two to three weeks. A new three-season porch runs four to eight weeks including permits and inspections.
Sunrooms & Three-Season Porches near you
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