Two questions come up at almost every deck walkthrough in Montgomery County: roughly what will this cost, and does the township need to be involved? The honest answers depend on the size, the height off the ground, and the material you pick. Here's how each one plays out.
This guide is written for homeowners in Norristown, King of Prussia, Collegeville, Phoenixville, Lansdale and the rest of Montgomery County & Greater Philadelphia. Rules inside the City of Philadelphia differ in places, and we note where.
Deck cost per square foot: composite vs. pressure-treated
Fixr, a national cost guide, puts a typical new deck at $9,000 to $20,000, and lists installed prices of $15 to $25 per square foot for pressure-treated wood and $28 to $40 per square foot for composite. Those are national averages, not local quotes, but they're a useful way to compare the two materials side by side.
| Pressure-treated wood | Composite | |
|---|---|---|
| Installed cost (Fixr, national) | $15 to $25 per sq ft | $28 to $40 per sq ft |
| 16 × 20 ft deck (320 sq ft) at those rates | About $4,800 to $8,000 | About $8,960 to $12,800 |
| Framing underneath | Pressure-treated | Usually pressure-treated too |
| Upkeep | Clean and re-stain or seal every few years | Wash it; no staining |
| Surface | Can check, splinter and gray with sun | Stays consistent; can run hot in full sun |
The 16 × 20 row is simple math on Fixr's per-square-foot figures, not a price for any specific deck. Real totals spread further once railings, stairs and height enter the picture. A common middle path is wood decking with a vinyl railing, since the railing is the part that needs the most painting.
These ranges come from Fixr and are national figures, not our prices. Every job gets a free written estimate, itemized by decking, framing, railing and stairs. Request yours below.
What drives the price of a deck in Montgomery County
- Height. A deck off a walkout or a second-floor slider needs taller posts, bigger beams, full guards and a long run of stairs. Height changes the price faster than square footage does.
- Railing. Wood, vinyl, and aluminum or composite systems vary widely per linear foot, and a raised deck can have a lot of linear feet.
- Stairs and landings. Each set of stairs adds stringers, treads, handrails and often a landing pad at the bottom.
- Attachment to the house. A ledger bolted to the rim joist needs flashing and sometimes siding removal. Brick or stone veneer walls usually mean a freestanding deck with its own beam and posts instead.
- Removing the old deck. Demolition and haul-away is its own line on the estimate.
- Design and permit. Drawings, the township fee, and inspection trips.
When you need a deck permit in Pennsylvania
Pennsylvania's Uniform Construction Code (UCC) applies in every township and borough, including Lower Providence, Upper Merion, West Norriton and the rest of Montgomery County. Under the UCC's residential permit exemptions, an uncovered deck whose floor is no more than 30 inches above grade does not need a building permit. That leaves most decks on the other side of the line:
- Deck floor more than 30 inches above grade: building permit
- A roof over the deck, making it a porch: building permit
- Any wiring, like outlets or lights: electrical permit
- Low, uncovered deck: no building permit, but zoning still applies
That last point catches people. Even when the building code exempts a deck, township zoning rules on setbacks from property lines and on lot coverage still apply, and many municipalities want a zoning permit or at least a plot plan review. HOA approval is a separate step on top of that. Inside Philadelphia, L&I runs its own permit and zoning process, so check with the city before building there.
Fees are set locally. Fixr puts typical deck permit fees at $100 to $500 nationally. Montgomery County municipalities each publish their own fee schedule, and deck fees are commonly based on square footage or construction value, plus a small state UCC charge. Expect to submit a plot plan showing the deck and its distance to property lines, and a framing plan with footing, beam, joist and ledger details. On our deck jobs, we prepare the paperwork, pull the permit and meet the inspector.
Deck code basics inspectors check
Pennsylvania currently reviews new permits under the 2021 International Residential Code. The items that come up on nearly every deck inspection in the Philadelphia suburbs:
- Footings below the frost line, which is 36 inches in most of southeastern PA; confirm your township's figure
- Guards at least 36 inches high on any deck more than 30 inches above grade
- Baluster gaps small enough that a 4-inch sphere can't pass
- Stair risers no taller than 7¾ inches and treads at least 10 inches deep
- A graspable handrail on any stair with four or more risers
- Ledger bolted to the house framing with flashing, never hung on brick or stone veneer
- Hot-dipped galvanized or stainless fasteners and hangers rated for treated lumber
Footing depth is the one people most want to shortcut, and it's the one that shows up years later as a sagging, heaving deck. Frost can lift a shallow footing every winter, pulling the deck away from the house.
Decks and railings from our job sites
These are our own exterior projects in the Philadelphia area. See more exterior photos, or read about our deck and porch service.
Deck cost and permit questions
Do I need a permit to build a deck in Montgomery County, PA?
If the deck floor is more than 30 inches above grade, or the deck has a roof, yes. Pennsylvania's UCC exempts only uncovered decks 30 inches or less above grade, and township zoning rules on setbacks and lot coverage can still apply to those.
How much does a composite deck cost compared to pressure-treated wood?
Fixr lists $28 to $40 per square foot installed for composite and $15 to $25 for pressure-treated wood. Those are national figures, not our prices. Every job gets a free written estimate.
How deep do deck footings need to be near Philadelphia?
Below the frost line, which is 36 inches in most of southeastern Pennsylvania. Your township sets the exact figure its inspector checks, so confirm it when you apply.
How much is a deck permit in the Philadelphia suburbs?
Each municipality sets its own fee, often based on square footage or construction value. Fixr puts typical deck permit fees at $100 to $500 nationally.
Can a deck be attached to a brick house?
Not to brick or stone veneer. A ledger has to bolt into the house framing, so veneer walls usually call for a freestanding deck with its own beam and posts along the house side.