Sunroom and Screened Porch Builder in Chantilly, VA
A sunroom or screened porch adds a room you will use three or four seasons a year without the cost of a full addition. Mosaic Design and Build frames site-built screened porches, four-season sunrooms with insulated walls and heating, and screened decks that match your home’s roofline and siding. We serve Chantilly, Sterling and homeowners across Fairfax, Loudoun and Prince William counties, and we pull the county permit for every project.
Porches and Sunrooms We Build
Pick the Room That Fits How You Will Use It
Northern Virginia summers bring mosquitoes and humidity, and winters bring enough cold to keep an unheated room empty from November to March. The right choice depends on how many months you want to use the space and whether it needs to feel like part of the house. We walk you through the options, show real costs for each, and build the one that fits your yard, your roofline and your budget.
A roofed, screened room on a new or existing deck frame. Ceiling fans, recessed lighting and a tongue-and-groove ceiling make it the most used room in the house from April to October.
Glass or vinyl window walls on a conditioned-ready frame. Comfortable from early spring through late fall, and ready for a heat source if you want to stretch the season.
Insulated walls, floor and roof, energy-efficient windows and a dedicated HVAC zone. Built as a true addition on footings, it is usable every day of the year and counts as living space.
Covered front porches, wraparound porches and screened sections added to existing decks, with composite decking, low-maintenance railings and roof lines tied into the house.
Screened Porch, Sunroom or Four-Season Room?
A screened porch keeps bugs and rain out and costs the least per square foot, but it is an outdoor room. A three-season sunroom adds window walls that block wind and pollen and can take a space heater or mini-split for shoulder seasons. A four-season room is built like an addition: frost-depth footings, insulated framing, a real roof assembly and its own heating and cooling, so it stays comfortable in January and adds appraised living space. Where the room sits matters as much as what it is: a south or west exposure needs shading and low-E glass, and a north-facing porch benefits from a lighter ceiling and more fixtures. We sort through those details on the first visit so the room you pay for is the room you will actually use.
Why Homeowners Choose Mosaic for Sunrooms and Porches
Porches and sunrooms fail at the connections: where the roof meets the house, where the floor meets the ground and where the glass meets the frame. We build those details to last.
Site-framed structures match your home's proportions and can be finished in any siding, trim and ceiling you choose.
Frost-depth footings, ledger flashing and step flashing at the roof tie-in keep water out of the house for the life of the room.
Porches and sunrooms count as additions in Fairfax and Loudoun counties; we check setbacks and submit the permit for you.
Framing, roofing, screens and finishes are covered in writing after the final walkthrough.
Our Process
How We Build Your Porch or Sunroom
The sequence is the same for a simple screened porch or a four-season room; only the structural steps change:
We look at the yard, the existing deck or slab, the roofline and the sun exposure, then price the options that fit.
Drawings, structural details and the county application are prepared and submitted by our team.
New footings go in, the floor and walls are framed, and the roof is tied into the house and flashed.
Screens or window walls, electrical, ceiling and trim are installed, and we walk the finished room with you.
Recent Porch, Sunroom and Outdoor Projects
See the work in person. Browse recent screened porches, sunrooms, decks and patios we have built across Northern Virginia.
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What Homeowners Say
Reviews from local families. Read what Northern Virginia homeowners say about working with Mosaic Design and Build on their outdoor rooms.
571-520-4088
Common Question
Sunroom and Screened Porch Questions
A screened porch on an existing deck frame is the most affordable option; a three-season sunroom with window walls costs more; a four-season room built on footings with insulation and HVAC is priced like an addition. We give a written range for each option after the site visit and a fixed price after design.
Yes. Any roofed structure attached to the house needs a building permit in Fairfax, Loudoun and Prince William counties, and it has to sit inside your setbacks. We check the setbacks, prepare the drawings and handle the inspections.
Often, if the deck has proper footings and framing for the added roof load. We inspect the posts, beams and ledger first; sometimes we add footings or sister joists, and sometimes a new frame is the safer choice.
A three-season room has window walls but no insulation or dedicated heating, so it is comfortable from spring to fall. A four-season room is insulated, sits on frost-depth footings and has its own heating and cooling, so it is a true year-round living space.
A screened porch usually takes three to five weeks on site; a four-season sunroom takes eight to twelve weeks. Design and permit review add four to eight weeks before construction.
A four-season room that is permitted and conditioned is counted as living space by appraisers. Screened porches and three-season rooms add usable space and appeal but are valued as outdoor rooms.
East and north exposures stay cooler and are easiest to glaze; south and west exposures get the most light and heat, so we add roof overhangs, low-E glass and shading to keep them comfortable in July.
Yes. We tie the new roof into the existing structure, match the pitch and shingles, and use siding, trim and ceiling materials that read as part of the original house rather than an add-on.
Let's Plan Your Porch or Sunroom
Tell us how you want to use the space and when, and we will visit, measure and give you clear options with prices. Call 571-520-4088 or email info@mosaicbuild.com.
Building Porches and Sunrooms Across Northern Virginia
Mosaic Design and Build works with homeowners in Chantilly, Sterling, Herndon, Great Falls and surrounding communities in Fairfax, Loudoun and Prince William counties.