It depends on size, height, and whether it’s attached to the house. Smaller, at-grade patios often don’t need one; patios that involve retaining walls, electrical for lighting or a kitchen, or are close to property lines sometimes do. We handle the permitting question as part of design, so you’re not the one figuring out King County or Seattle DPD requirements on your own.

A slope doesn’t rule out a patio; it just means the design has to account for it, usually with grading, a low retaining wall, or a stepped layout. What we won’t do is build a flat patio on a slope without solving where the water goes, because in a wet climate like ours, that’s exactly what leads to a patio that heaves or drains straight toward your foundation instead of away from it.

Concrete pavers, poured concrete, and natural stone are the two that consistently perform well here, both handle our wet winters and freeze-thaw swings without cracking the way lower-grade poured concrete can over time. Porous or textured surfaces also help with the moss and algae that show up on anything shaded and damp for months at a time. The most important aspect is proper installation. An experienced installer can mitigate most weather-related issues and increase the lifetime of the patio.

It can be added later, but it’s cheaper and cleaner to plan for it upfront. Gas lines, electrical, and the extra base support a kitchen or fire feature needs are far easier to run before the pavers go down than to retrofit into a finished patio. If there’s any chance you’ll want one down the road, mention it during design so we can at least rough in the groundwork now.

In Seattle, this usually comes down to grade and drainage more than style preference. If your yard is relatively flat and the ground drains reasonably well, a patio is often the simpler, lower-maintenance choice. If you’re dealing with a steep drop-off, poor drainage right at the house, or want to get up and away from a consistently soggy area, a deck can solve problems a patio can’t. We’ll look at your actual grade and drainage during the site visit rather than defaulting to one or the other.

It depends on the tree and how close it is. Established conifers and big-rooted trees common in Seattle yards can heave a patio over time if it’s built too close, and roots cut carelessly during excavation can stress or kill a mature tree you actually want to keep. We account for root zones when we design the layout, and in some cases a permeable paver system is the better call specifically because it lets water and air keep reaching the roots underneath.