Before buying: measure the real slab/deck, verify permit and wind/snow requirements locally, and confirm current model specifications with the manufacturer. PergolaSpec has not physically tested every product listed.
Quick comparison
| Decision | Attached | Freestanding |
|---|---|---|
| House interface | Ledger/flashing and verified wall structure | Independent; avoid unintended contact |
| Posts | Potentially fewer near the wall | Usually four or more |
| Foundation | Posts plus wall load path | All loads go to posts/footings |
| Water risk | Penetration and drainage at façade | Outlet placement away from foundations |
| Flexibility | Tied to building geometry | Easier to position independently |
Attached is a building-envelope decision
A safe attachment depends on what is behind the cladding, not simply where a ledger appears to fit. Flashing, water control and structural fastening need a compatible detail. Do not attach only to veneer, trim or an unverified fascia.
Freestanding is often simpler—but still engineered
Independent posts avoid wall penetrations and can make replacement easier, but add footing/anchor locations and consume clear floor area. Keep roof drainage from discharging against the house or foundation.
Use the size planner to compare post zones for both layouts.