If you’re lucky, your Vineyard getaway or year-round home already has a porch or an attached arbor, maybe even both. Each creates a space that is neither indoors or out, a delightfully in-between space where you can savor island breezes, salty scents, and framed views all from within a partial shelter. But if you’re thinking of building, renovating, or adding on, you might want to consider the distinct benefits and tradeoffs of a porch versus an attached arbor.

The advantage of a porch, which by definition includes overhead cover, is that it provides protection from passing showers and harsh, high, summer sun. As a result, wicker and cedar furnishings on a porch typically out endure furnishings of the same material on an attached arbor or patio. Thanks to its ceiling, a large open porch (often referred to as a veranda when it also includes a guard rail) can feel more room-like than an attached arbor. A disadvantage of a porch is that, depending on its depth, it can darken adjacent rooms that look onto and through it. Painting the porch ceiling a light, sky blue is a Vineyard touch that can help lighten both the space below and neighboring rooms whose windows border the porch.

An attached arbor (sometimes incorrectly identified as a pergola, which is a colonnade with an open structure above) is much more porous than a porch. It offers filtered daylight and exposure to showers, depending on how dense the structure and/or plant life atop it is. The overhead structure alone can create interesting shadow lines, and the addition of climbing plants like wisteria, grapevine, clematis, etc. can soften the feel and lend color, scent, and texture, while gently buffering the elements. Rooms with windows that look onto or through an attached arbor don’t generally suffer from the intrinsic shade a porch affords. When an attached arbor extends over a deck and includes a semi-solid guard rail as in the example shown here, it borrows attributes often associated with more room-like porches, while providing airiness overhead. An attached arbor can also transition nicely to an even more open patio.

If you’re trying to decide between building (or occupying) a porch or an attached arbor, consider how enclosing you desire both the space itself and those adjacent to it to feel. Whichever you choose, enjoy the nuance of a space that is both indoors and out, on an island like no other.

Katie Hutchison is a New England architect with Vineyard family and clients. She’s the author of The New Small House. More at katiehutchison.com