Screened porch and enclosure

A screened porch buys back the seven months you already paid for

A screened porch is a roofed, screened room attached to the house. In Southeast Michigan it is the cheapest square footage you can add per usable hour, because it turns a deck you use on maybe twenty good evenings into a room you use from mid-April through mid-November. Add a ceiling fan and a heater and it stretches into early December.

Market ranges here fall into two very different jobs. Screening in an existing deck runs $15,000 to $30,000 for a 150 to 200 square foot space. Building new from the ground up runs $25,000 to $60,000 for 200 to 300 square feet. Premium builds with heavy timber, a cathedral ceiling and a fireplace reach $70,000 to $100,000.

Per square foot that is $70 to $180 for a screened porch, against $55 to $120 for an open composite deck and $150 to $300 for a full sunroom. Converting a deck that already has sound footings costs 40 to 60 percent less than starting over, so the first question we ask is what you already own.

Whether your existing deck can carry a roof

A deck holds people. A screened porch holds people plus a roof plus whatever snow lands on it, and that is a different load path entirely. Plenty of decks in this region cannot take one without new footings, and finding that out after the framing starts is expensive.

Footings are the first check. Michigan’s frost line sits at 42 inches, and we set porch footings to 48 inches, six inches of margin below it. A deck built on surface blocks or shallow piers gets new footings regardless of how solid it feels in August. Freeze and thaw lifts anything that stops short, and a roof that moves takes the screen frames and the door with it.

Then the roof itself. Our counties size for a ground snow load of at least 25 pounds per square foot, which puts rafters at 2×8 or 2×10 depending on the span. The tie-in to the existing house roof is where water gets in if the flashing is wrong, and it is the detail worth asking any bidder to explain. Our Michigan screened porch guide covers the structural assessment, and the screened porch addition writeup covers layout.

Screen is a material choice, not an afterthought

Three options cover almost every porch we build, and they behave differently enough that the choice belongs in design rather than at the supply house.

• Fiberglass mesh is the default. It is affordable, holds up to UV, and does not dent when a kid leans on it the way aluminum does.
• Aluminum resists tears better and lasts longer, at the cost of a visible haze that dulls the view.
• Heavy-duty pet-resistant mesh is worth it on a wooded lot or with a dog that pushes, and it is thick enough to notice.
• Fixed screen panels are the simplest and cheapest frame system, while removable panels let you swap in glass.
• Retractable systems run $150 to $300 per linear foot and turn a screened room into an open one on demand.

Two details that get skipped and should not. The floor gets sloped an eighth of an inch per foot so rain that blows through drains out instead of standing. And code wants a minimum of two GFCI-protected duplex outlets per wall, which is also just the right number once you own a fan, a lamp and a laptop out there.

Three seasons or four, and what the jump costs

A screened porch is a three-season room by definition. It is outdoor air with the bugs filtered out, and that is the point. If you want to use it in February you are talking about a different building.

Enclosing with glass and adding heating and cooling turns it into a sunroom. Market ranges for a three-season sunroom addition run $40,000 to $60,000, and a fully conditioned four-season room runs $60,000 to $75,000 and up. Our comparison of a three-season against a four-season room in Michigan is the piece to read before choosing, and the sunroom cost breakdown has the line items.

The design decision worth making now is whether to build the porch so it can be enclosed later. Footings, framing and roof sized for a future glass wall cost a little more today and save a rebuild in five years. If the answer is probably yes, say so at the first meeting.

The build window is short and it is in spring

Permit fees run $300 to $800 in Washtenaw County depending on the valuation, and review takes one to three weeks. Construction itself is fast, generally three to six weeks for a deck conversion and longer for a new structure with footings.

The window that matters is March through May, aiming for completion by Memorial Day, because that is what gets you a full season out of the thing the year you pay for it. Concrete wants unfrozen ground, which rules out January and February for footings, and a porch finished in October is a porch you look at until spring. The calendar for outdoor work here fills early, so the useful move is to design in winter and build in spring.

One scheduling note that saves money. Footings and framing can go in during a shoulder month while the screen and the finish work wait, so a project that misses the spring window is often better split than delayed a full year. We will tell you which half is worth doing now.

Disruption is mild compared with anything interior. You lose the back of the house and the yard beside it. Nothing inside gets shut off except during the roof tie-in and the electrical connection, both of which are scheduled hours rather than days.

Where a porch beats the alternatives

On the wooded lots around Dexter, Chelsea and much of Livingston County, mosquitoes decide whether an open deck gets used at all, and screening is the difference between a nice structure and a used one. On the older lots near Ypsilanti and Ann Arbor, many houses already have a covered front or side porch that can be screened for a fraction of new construction.

Where a porch is the wrong answer is when what you actually want is more indoor space year round. A screened room does not add heated square footage, does not appraise like it, and will not solve a house that is short a bedroom. That is a room addition conversation. If the goal is entertaining, an outdoor living room or hardscaping with a fire feature sometimes gets you further per dollar.

The details that decide whether you use it

A porch that gets used every evening and one that gets used twice differ by a handful of decisions that cost very little at design and cannot be added later.

Ceiling height and roof form come first. A flat eight-foot ceiling on a screened room reads as a covered patio. A vaulted ceiling that follows the rafters, with the framing exposed and finished, makes the same footprint feel like a room, and it costs almost nothing extra while the rafters are going in anyway. Ceiling material matters as much as height, and tongue-and-groove pine or a painted bead board turns the surface you actually look at into something worth looking at.

Then light. A fan-rated box in the ceiling is cheap during rough electrical and expensive afterward, and a fan is what makes a July evening tolerable. Dimmable perimeter light on a separate switch is what makes the porch usable after nine o’clock. A wired-in heater or an infrared unit is what buys the November and early December weeks, and it wants its own circuit sized during design rather than borrowed later.

Sightlines are the last one, and the cheapest. Screen frames want to be as few and as wide as the structure allows, because every post and every rail is something you look through for the next twenty years. Where a post has to land, landing it off the center of the view rather than in it is a five-minute conversation with a real payoff.

What is in the price and what is not

A Wright’s screened porch budget includes design and permit drawings, permit fees and inspections, footings and foundation work, framing, the roof and its tie-in and flashing, the ceiling, screen frames and mesh, the screen door, decking or the finished floor with drainage slope, electrical with GFCI outlets and a fan-rated box, trim and paint, and daily photo updates.

It does not include furniture, a fireplace or heater unless contracted, landscape restoration beyond the work zone, or repairs to an existing deck found to be unsound once we open it up. If the footings have to be replaced or the ledger board is rotted, that comes to you as a written change order with the cost and the schedule effect attached before anyone continues. Staining and long-term care of any wood we leave exposed is covered on deck staining and maintenance.

Questions we get asked

Do I need a permit for screening in an existing deck

Yes, in every jurisdiction we work in. Adding a roof changes the structure and the load, and it triggers a plan review. Unpermitted porch roofs turn up during home inspections and they are a bad surprise at closing.

Will it make the room behind it dark

Somewhat, and it is worth planning for. A porch off a kitchen or family room cuts the daylight reaching that room, which is why we look at skylights in the porch roof, a lighter ceiling finish, or shifting the porch off the main window wall. Ask to see it studied before you commit to the location.

Can the screen stay up all winter

Fiberglass and aluminum both winter fine. What suffers is anything you leave out there, and snow that blows through will sit on the floor until it melts, which is exactly why the floor gets a slope and a drainable surface.

Is a deck conversion always cheaper

Only if the footings and framing check out. A conversion runs 40 to 60 percent less when the structure is sound, and roughly the same as new construction when the footings have to be replaced. We check first and tell you which one you have.

Come stand where the porch would go

We are a design-build contractor in Ypsilanti, so the drawings, the permits and the crews are all ours under one contract. See how a project runs, browse outdoor living projects, or view our portfolio. If the yard needs work in the same season, say so early and it gets designed as one project rather than two mobilizations.

Contact us now for a free quote, or call the shop at (734) 540-0347. Twenty minutes with a tape and a shovel tells us whether your footings are usable, and that answer moves the budget more than any material you pick. Request an estimate to get on the spring calendar.