Three-season: a beautiful room, eight months a year

A three-season sunroom is typically built on an existing deck or patio footprint with single-pane or lightly insulated glass systems and no permanent heating. It is glorious from April through October and a storage room from December through February. The cost sits at the friendly end of our addition range of $120,000–$325,000 precisely because structure, insulation and HVAC demands are lighter. Choose it with eyes open: it is a porch with benefits, not a room.

Four-season: a real room that happens to be glass

A four-season sunroom is an addition in full: insulated foundation, double-pane low-E glass, a roof that carries snow load and ties into the house, and heating and cooling sized for the glass area. It reads on an appraisal as living space, gets used on Christmas morning, and in Maryland's climate is where the room earns its keep. The structure and systems cost more — and they are the entire point.

The Maryland specifics: orientation, water and permits

A south-facing glass room needs shading strategy or summer turns it into a greenhouse; west glass cooks at dinner time. Waterfront properties in Anne Arundel and Calvert add critical-area review to the permit path. And converting an existing deck is rarely the shortcut it appears — most deck footings were never sized for a roof, so the foundation work happens either way. We assess all three during design, before the fixed price.

Our honest recommendation

If the room is for plants, summer evenings and a telescope, three-season is a joy at a fair price. If it is for your life — reading in January, grandkids in December, a desk with a view — build the four-season version once. Either way, start with the lot and the light at a free in-home visit: call (240) 266-8317.

Frequently asked questions

Can a three-season sunroom be upgraded to four-season later?

Rarely economically — the foundation, glass and structure all change. The conversion question is exactly why we push the decision before building, not after the first cold January.

Does a sunroom need a permit in Maryland?

Yes — a sunroom is an addition: building permit, foundation and structural review, and electrical permits for any circuits. Waterfront lots may add critical-area review.

Will a sunroom add appraised living space?

A four-season sunroom with permanent heat, built to residential standards, generally counts as living area. A three-season room usually does not — another reason the distinction matters.