Basement Egress Windows
Basement Bedrooms and Egress Windows in Lehigh County, Pennsylvania
Short answer
You only need an egress window if someone is going to sleep in the basement.
- Bedroom in the plan
- Foundation cut, engineered header, permit
- No bedroom
- No foundation work at all
- The opening
- 5.7 sq ft net clear, 24 in high, 20 in wide, sill max 44 in
- The window well
- 9 sq ft minimum, 36 in projection, drained
- Code in force
- 2021 IRC as adopted in Pennsylvania, R310
Not sure yet? Frame the opening location into the plan now. It is far cheaper than cutting it in after the drywall is up.
Most homeowners are told they need an egress window to finish a basement. Under the code Pennsylvania actually enforces, that is only true if someone is going to sleep down there. Here is the rule, the dimensions, and what it costs to get one permitted.
- Net clear opening
- 5.7 sq ft minimum
- Minimum height
- 24 in
- Minimum width
- 20 in
- Maximum sill height
- 44 in above floor
- Code in force
- 2021 IRC, PA amended
Can you put a bedroom in a basement in Lehigh County?
Yes. A basement bedroom is legal in Lehigh County as long as that room has a compliant emergency escape and rescue opening, which in almost every case means an egress window and a window well. That is the whole requirement. It is not a gray area and it is not up to the inspector's mood.
We get this question constantly from homeowners in Allentown, Bethlehem, Emmaus, Macungie, Whitehall and Lower Macungie Township, and it is usually asked backwards. People ask whether they need an egress window. The question that actually decides the job is whether anyone is going to sleep down there.
If the answer is yes, that room needs the opening, which means cutting the foundation wall, an engineered header, and a permit. If the answer is no, you are finishing a basement with no foundation work at all. The rest of this page is the code, the dimensions and the cost behind that decision.
What makes a basement bedroom legal
- An emergency escape and rescue opening in that room, 5.7 sq ft net clear, 24 in high, 20 in wide, sill no more than 44 in above the finished floor.
- A window well at least 9 sq ft with a 36 in projection, drained to the foundation drainage system.
- Ceiling height of at least 7 ft in the habitable space.
- A smoke alarm inside the bedroom and one outside the sleeping area, plus a carbon monoxide alarm where there is fuel fired equipment.
- Heat to the room, and a permit with inspections on the structural opening and the final.
The rule that decides whether your basement job is normal or expensive
Pennsylvania moved to the 2021 International Residential Code on January 1, 2026, under 34 Pa. Code section 403.21. In that edition, the rule for existing basements is section R310.7, and it reads:
New sleeping rooms created in an existing basement shall be provided with emergency escape and rescue openings in accordance with Section R310.1. Other than new sleeping rooms, where existing basements undergo alterations or repairs, an emergency escape and rescue opening is not required.
It is a two way switch. Finishing an existing basement with no bedroom in it: no escape opening required, no foundation cut, no engineer, no window well. Creating any sleeping room in that basement: an escape opening is required in that room, which means cutting the foundation wall, which means an engineer and a permit.
That is the whole decision, and it is worth several thousand dollars. It is also the single most common thing we are asked to correct on a quote somebody else wrote.
One warning. The section number moved. R310.6 was the existing basement rule in the 2018 code, and in the 2021 code R310.6 is dwelling additions. Anyone citing R310.6 for a basement finish today is a code cycle out of date.
The dimensions, and the trap inside them
When an opening is required, these are the numbers it has to meet.
| Requirement | Minimum | Section |
|---|---|---|
| Net clear opening area | 5.7 sq ft minimum | R310.2.1 |
| Net clear area, grade floor openings | 5.0 sq ft minimum | R310.2.1 exception |
| Net clear opening height | 24 in minimum | R310.2.2 |
| Net clear opening width | 20 in minimum | R310.2.2 |
| Sill height above finished floor | 44 in maximum | R310.2.3 |
Net clear is not the rough opening
Section R310.2.2 says the net clear opening dimensions are the result of normal operation of the opening. That means you measure the hole a person can actually climb through when the window is open, not the size of the unit you bought.
A double hung gives you roughly half its height, because the lower sash stops at the meeting rail. A slider gives you roughly half its width. A casement swings fully clear, which is why a casement is usually the only unit that makes 5.7 square feet inside a basement sized rough opening.
This is where cheap egress jobs fail inspection. Get the manufacturer's published net clear figure in writing before the window is ordered, not after it is installed.
The window well is half the job
The opening is only compliant if what is outside it is compliant too.
| Requirement | Rule | Section |
|---|---|---|
| Window well horizontal area | 9 sq ft minimum | R310.4.1 |
| Well projection and width | 36 in minimum each | R310.4.1 |
| Ladder or steps required | Wells deeper than 44 in | R310.4.2 |
| Ladder encroachment allowed | 6 in maximum into required well size | R310.4.1 exception |
| Drainage | Connect to the foundation drain required by R405.1 | R310.4.3 |
The well also has to let the window open fully. A well sized to the minimum with a window that swings into it is not a compliant assembly, and that is a detail an inspector will catch at final.
Drainage is the step the lowest bid skips. R310.4.3 requires the well to connect to the foundation drainage system, with an exception only where the foundation sits on well drained soil or a sand and gravel mixture. Do not assume that exception applies. Prove the soil or run the drain.
The alternative most people are never told about
Section R310.1 carries an exception for sprinklered homes. Where the dwelling has an automatic sprinkler system installed in accordance with Section P2904, basement sleeping rooms do not require an escape opening, provided the basement has one means of egress under R311 plus one escape opening, or two means of egress under R311.
On a basement with one bedroom, cutting the wall is almost always cheaper. On a basement with three bedrooms and a walkout already in place, the sprinkler route can come in under the cost of three foundation cuts, three engineered headers and three window wells.
We price it both ways when the job has more than one sleeping room in it, and we show you both numbers.
How we do it
Five steps. The first one is the one that saves you money.
- 01
Decide whether you actually need one
This is the first question and most of the time it is the only one that matters. If the finished basement contains no sleeping room, the code does not require an escape opening. If any room in it will be slept in, that room needs one.
We settle this before anything is drawn, because the answer changes the price by thousands of dollars.
- 02
Measure the wall and find the utilities
We locate the sill plate, the grade line outside, the depth to the footing, and anything buried where the well goes. Gas line, water service, electric service, septic lateral and the foundation drain all live in that zone.
We also check whether the yard outside the proposed opening actually leads to a public way, because the code requires that path, not just the hole.
- 03
Engineering and the permit
Cutting a new opening in a foundation wall removes a section of bearing wall. That is a structural alteration, so it needs a Pennsylvania licensed professional engineer's design for the header and the load path, and it needs a permit.
We draw the permit set in house and pull it with your township. Nobody finishing a basement should be cutting concrete on a handshake.
- 04
Cut, set, waterproof, backfill
The opening is saw cut, the header set, the unit installed and flashed, the well anchored to the wall, the drain tied to the foundation drainage system, and the backfill compacted so the well does not settle away from the house.
The drain is the step most commonly skipped by the cheapest bid. A window well with no outlet is a bathtub sitting against your foundation with a window at the bottom of it.
- 05
Inspection and final
The township inspects the structural opening and the final assembly. We are there for both. You get the approved permit card and the inspection record as part of the closeout package.
What it costs
We publish a rate for finished basements, $75 to $125 per square foot with a $50,000 project minimum. An egress window is priced separately as its own line, because the cost is driven by conditions rather than by area.
The variables that move the number: how deep the foundation wall is below grade, whether it is poured concrete or block, what the engineered header has to carry above the opening, whether the foundation drain is reachable or has to be extended, whether anything is buried where the well goes, and how far the spoil has to be carried out.
The permit is a published number and we pass it through at cost. In Upper Macungie Township the 2026 schedule lists an egress window or Bilco door at a minimum of $150.00, plus the 25 percent administrative fee applied to all UCC permits, plus the $4.50 Pennsylvania UCC state fee. Every township publishes its own schedule and they differ, so we pull yours and put the real figure in the written scope.
We do not quote an egress window over the phone. We measure the wall, find the utilities and confirm the path to the public way first, then the number is a number rather than a guess.
Your own township's website is four code editions out of date
This is worth saying plainly because it explains why so many people are given the wrong answer. As of September 2026, Upper Macungie Township's own basement permit page publishes the emergency escape requirements from the 2009 International Residential Code. Pennsylvania is on the 2021 edition. That page is four cycles behind.
The consequence is specific, not academic. The 2009 text reproduced there has no equivalent of R310.7, so a homeowner reading it would conclude that every finished basement needs an escape opening. Under the code actually in force, one with no sleeping room in it does not.
We are not saying this to criticise the township. Municipal web pages go stale everywhere and the inspectors enforce the current code regardless of what the website says. We are saying it because you should know that reading a township page, or asking an AI assistant, is not the same as reading the adopted code, and because we would rather you check us than take our word for it. The link is in the sources at the bottom of this page.
What that same township does want, verified
- Three copies of all documentation and one completed application.
- A floor plan detailing wall sheathing, insulation, interior finish, ceiling joists, fire blocking, studs, flooring and sub-flooring.
- A certificate of insurance for every contractor listed, naming Upper Macungie Township as certificate holder.
- Most applications take about 15 business days to process, and no fees are due until the permit is reviewed, approved and issued.
- Grinder pump installations cleared with the Township Authority before the application is submitted.
Common questions
Does every basement need an egress window?
No. Under the 2021 IRC as adopted in Pennsylvania, section R310.7 says that where an existing basement undergoes alterations or repairs, an emergency escape and rescue opening is not required, other than for new sleeping rooms.
So a family room, a gym, a bar, a theater or an office in an existing basement does not trigger the requirement. A bedroom does. That single sentence is the difference between a straightforward finish and a job that includes cutting a foundation wall.
Is it illegal to have a bedroom in the basement without an egress window?
A new sleeping room created in an existing basement must have an emergency escape and rescue opening meeting R310.1. A basement bedroom without one does not comply.
The practical risk is not abstract. The drawing is what the inspector reads. A room labeled as a bedroom with no escape opening is a failed final inspection and a wall that has to come back open. Calling it an office with a bed in it does not change what it is.
Can you finish a basement without an egress window?
Yes, provided no room in it is a sleeping room. That is the most common finished basement we build.
If you want the option of a bedroom later, tell us at the design stage. Framing the opening location into the plan now is far cheaper than cutting it in after the drywall is up.
Does a 3 by 5 window meet egress?
It depends entirely on how the window operates, not on its overall size. The code measures the net clear opening produced by normal operation, not the rough opening and not the frame.
A double hung only gives you about half its height, because the lower sash stops at the meeting rail. A slider only gives you about half its width. A casement swings fully clear and is usually the only unit that makes 5.7 square feet in a basement sized opening. Get the manufacturer's published net clear figure in writing before anyone orders the window.
Do I need an egress window if I have a walkout basement?
Usually not for the walkout itself. The code requires an emergency escape and rescue opening, and a complying exterior door can serve as that opening.
The requirement is per sleeping room, though. A walkout door at one end of the basement does not cover a bedroom framed at the other end behind a closed door. We confirm this room by room against the adopted code on every job.
Does a basement bathroom need an egress window?
No. A bathroom is not a sleeping room, and the escape opening requirement is tied to sleeping rooms and to the basement as a whole.
Bathrooms have their own requirement, which is ventilation. A basement bathroom needs either an openable window or mechanical exhaust ducted to the outside, and in a basement it is almost always mechanical exhaust.
Can I install my own egress window?
Cutting a new opening in a foundation wall is a structural alteration. It requires an engineered design and a permit, and in most Lehigh County townships it will not be inspected without both.
Replacing an existing basement window in its existing opening is a different and much smaller job. Removing a section of bearing foundation wall is not homeowner work, and a DIY cut that cracks a wall is not a repair you want to price.
How much does an egress window permit cost?
In Upper Macungie Township the published 2026 fee for an egress window or Bilco door is a minimum of $150.00, plus a 25 percent administrative fee on all UCC permits, plus the $4.50 Pennsylvania UCC state fee.
Every township publishes its own schedule and they differ. We pull the current fee schedule for your municipality and put the real number in the written scope rather than an estimate.
Is there a way to add a basement bedroom without cutting the foundation?
Sometimes. The code provides a sprinkler alternative. Where the dwelling has an automatic sprinkler system installed to Section P2904, basement sleeping rooms do not need an escape opening, provided the basement has one means of egress plus one escape opening, or two means of egress.
On a high end job with several basement bedrooms, running sprinklers can come in under the cost of multiple foundation cuts and window wells. It is worth pricing both ways rather than assuming the window is the only route.
What about replacing an existing undersized basement window?
Section R310.5 exempts a replacement window from the dimensional requirements, provided it is the manufacturer's largest standard size that fits the existing frame or rough opening, it is the same operating style or one with an equal or greater opening area, and it is not part of a change of occupancy.
This is how an existing small basement window gets swapped legally without enlarging the hole. It does not turn that window into a compliant escape opening for a new bedroom.
Is it worth it to install an egress window?
It is worth it if you want a legal bedroom, a legal guest suite or an in law suite in the basement. It is not worth it for a rec room that will never be slept in.
The value is in what the room is allowed to be called. A basement bedroom with a compliant escape opening and a permit record is a bedroom. Without one it is finished square footage that an appraiser, a buyer's inspector and your insurer will each treat differently.
How long does it take?
The cutting, setting and backfilling is usually a few days on site. The schedule is driven by the engineering and the permit ahead of it, and by the window lead time.
We sequence the engineering and the permit application at the same time as the rest of the basement design so the foundation work is not what holds up the job.
Can you put a bedroom in a basement in Pennsylvania?
Yes. Pennsylvania enforces the 2021 IRC, and a new sleeping room created in an existing basement is permitted provided it has an emergency escape and rescue opening meeting Section R310.1.
The requirement attaches to the room, not to the basement. One compliant opening in the family room does not cover a bedroom framed behind a closed door at the other end.
Does a basement bedroom count as a bedroom for appraisal?
An appraiser generally counts a below grade sleeping room as a bedroom only where it has a compliant escape opening and the permit record to back it up.
This is the practical reason the window is worth the money. With the opening and the permit it is a bedroom on paper. Without them it is finished square footage, and an appraiser, a buyer's inspector and your insurer will each treat it differently.
How much does it cost to add a bedroom to a basement in Lehigh County?
The finished space runs $75 to $125 per square foot with a $50,000 project minimum. The egress window is priced as its own line because its cost is driven by site conditions rather than by floor area.
What moves the window number: how deep the wall sits below grade, poured concrete or block, what the engineered header has to carry, whether the foundation drain is reachable, and whether anything is buried where the well goes.
Do I need a permit for a basement bedroom?
Yes. Cutting a new opening in a foundation wall is a structural alteration, and the bedroom itself triggers electrical, alarm and mechanical work that is inspected.
We draw the permit set in house, file it with your township and stand at the inspections. The approved permit card and the inspection record are part of the closeout package.
Where these numbers come from
Every number on this page links to the text it came from. Open any of them and check us.
- 01IRC 2021 R310.7, Alterations or repairs of existing basements
The section that decides whether a basement finish needs an escape opening at all.
- 02IRC 2021 R310.1, Emergency escape and rescue openings required
When an opening is required, and the sprinkler exception that can replace it.
- 03IRC 2021 R310.2, Emergency escape and rescue openings
The 5.7 square foot net clear area, the 24 inch height, the 20 inch width and the 44 inch maximum sill.
- 04IRC 2021 R310.4, Window wells
The 9 square foot minimum, the 36 inch projection, the ladder above 44 inches deep and the drainage requirement.
- 0534 Pa. Code 403.21, Uniform Construction Code
Pennsylvania's own regulation. Names the adopted code edition, reprints the amended energy tables and carries every Pennsylvania amendment quoted on this page. Amended 7 November 2025 at 55 Pa.B. 7701, effective 1 January 2026.
- 06Upper Macungie Township, basement permit requirements
What the township wants in a basement submission: three copies of all documentation, one completed application, a detailed floor plan, and a certificate of insurance naming the township for every contractor. Note that as of September 2026 this page still quotes the 2009 IRC.
- 07Pennsylvania Attorney General, contractor registration search
Check PA225448, or any other contractor's registration, against the state's own record before you sign anything.
Every dimension and section number on this page is quoted from the 2021 International Residential Code as adopted by Pennsylvania under 34 Pa. Code section 403.21, effective January 1, 2026, including the Pennsylvania amendments. The permit fee is quoted from the Upper Macungie Township fee schedule effective January 5, 2026.
Lehigh Valley Builders Group LLC is a Pennsylvania Registered Home Improvement Contractor, PA225448. We draw our own permit sets, pull them, and stand at the inspections.
Thinking about a bedroom down there?
Tell us what rooms you want down there. If none of them is a bedroom, we will tell you that you do not need an egress window.