How to Read Construction Blueprints:12 Simple Steps to Master This Essential Skill

Introduction

How to read construction blueprints, by far, it’s one of the most complicated things when it comes to building. A lot of carpenters don’t understand exactly what they’re looking at. Now, today I’m gonna sit down with you guys and explain a couple of different things that really help you guys understand what you’re looking at when you have a set of plans like this.

Now, since this is my office and not the office where we do business, I don’t have a plan table. We’re gonna roll with it. I’m gonna show you guys a couple of things, let you guys know the difference between architectural and structural, and go over a couple of different things for both. Hopefully, you took something away from it.

1. How to read construction blueprints and the Cover Sheet

So typically when you have a set of plans, you have a cover sheet which will have a 3D rendering of the home along with a bunch of info about where it’s located, what’s going on, a complete scope of work. Since we’re only doing the framing on this project, the only thing we print out is our structural, architectural and elevations.

Those three things right there allow us to frame from concrete up. So we are on a 1.0, this is our site plan. This is going to give us a basic rundown of what’s going on on the property. Now how to read construction blueprints as a puzzle, everything here has a place. The architectural site plan legend is up here in the corner and it tells you what each individual mark means. You have key notes here with numbers and circles that go to one spot or another. 

2. Recognizing Utility Lines and Lot Constraints

Now one thing you can check out how to read construction blueprints, you have a water line, a gas line, a sewer line and an electrical line.

• Here you can find your gas line there, electrical lines right out there, water lines run all over the place.
• These are things you can look out for before you’re either digging or doing other work.
• Now since we’re framing this project, the only thing we really have to look out for is that electrical line right there.
• We don’t have equipment on this project since the lot right there, it’s pretty narrow.
• We actually can’t get a lift anywhere on-site.
• We have a home here, home here, street runs along here.
• Now another thing the site plan does, it tells you exactly where the lot is and how big it is.
• As you can see, we got a little pie shape going on here.
• There’s nowhere to get equipment in.
• We have an existing garage here, existing home is here, addition goes here and there is nowhere to get a lift in.

3. Material Staging and Site Strategy

• Now our game plan here, we’re going to have all of our material dropped right here in the driveway.
• Our laborers are gonna pack it back to the addition that goes for all of our plate, all of our studs, our floor system, roof system, everything.
• Now on your site plan here as well you’ll find little circles with numbers inside of them to reference on your key notes here.
• Number one, for instance, which is right in here, residence to be renovated.
• Number two, residence to remain, not in the scope.
• So nothing is changing with this side of the home but this site here is affected.
• Number three, main house addition with new 610 square foot ADU unit above.
• Now this here is going to have a list of things for not only the framers but every trade.
• How to read construction blueprints here, they’re basically giving you guys a rundown on what’s going on.
• All these key notes here that you can reference have anything to do from the fruit trees that are being removed to put in the new sidewalk to what’s going on with the addition.

4. Reading the Floor Plan for Framing

Now we’re going to go ahead and flip here and start looking at the stuff that actually has to do with framing. Now we’re not gonna look at any of this here, the only thing we want to look at today is our floor plan that we’re going to be building. So we are now on architectural 2.1. 2.0 was actually a demolition floor plan, we don’t need that because we’re not doing demo.

One thing to keep in mind when you first start how to read construction blueprints that helped me out tremendously is understanding the difference between an architect and a structural engineer. Architects make things pretty and engineers make things work.

5. Architectural Layout and Measurements

• Here we have a floor plan for the fact that we will frame.
• As you learn how to read construction blueprints, you will see that the architects attract details here as a bath, two sinks and a hatched cabinet.
• On the other hand, engineers do not provide that type of information – they only focus on what is needed to meet the construction code requirements.
• Conversely, the architect will clearly indicate where all the windows are placed.
• Therefore, how to read construction blueprints, it is necessary to understand what details provide.
• When we get to the place, it is the first line along this wall – five and a half meters up – and then snaps another line for the inner wall.
• From there you can see a measure of 31 feet 4 inches on that side in the length of the building.
• Whatever it does, it ensures that by measuring 31 feet 4 inch diagonally from the corner to the corner, we remain completely parallel.
• You should never think that concrete is perfect.
• If one side measures 31 feet 4 inches and the other comes up to 31 feet 5 inches, you are already away from an inch – and it is not acceptable.
• This is why it is important to know how to read construction blueprints properly before starting a layout work.

6. Window and Door Layout Basics

• Before putting spikes in this wall, note where your windows are and first keep them out.
• As you can see here, we have 2 feet 8 that hooks outside the plate in the middle of the window.
• You have written ‘105’ and a small diamond, which is used for reference on the window and door plan – we will cover something like that soon.
• So now that you have excluded that window, we’re going to exclude one next door.
• Usually they will have another number in the middle and you will just notice the center.
• But in this case, as you can see, we found 1, 2, 3, 4, 5 numbers in the center.
• This is the place where a construction calculator is used.
• We have 5 feet 9, 22 feet one, so there is a 22-foot hooked outside your center of your window.
• From there you can find out what is the size of 104, and draw that window accordingly.
• It is necessary to understand this how to read construction blueprints and avoid expensive errors for the exact design.
• This helps you explain measurements, symbols and schedules with confidence.
• Learning how to read construction blueprints will also allow you to imagine the construction before you place a single spike.
• Whether you are taking a beginning or looking to improve your skills, it is a basic step towards successful construction projects.

7. How to read construction blueprints, Continuing the Wall Layout

Now it’s going to be the same exact thing all the way around, whether it be a door or a window. They all lay out the same. So you have these marks here that determine where your center is going to be and these are all things listed on the architectural. Now before any of your plating goes down, you’re gonna snap lines on your slab which you guys will see on our builds for you starting tomorrow.

You would hook that corner there and go five foot nine, you give yourself a mark and go back three and a half, and that is for that interior 2×4 wall. So now you would butt that wall right there and pull five foot five over the next one, go back three and a half to there, and that’s that wall. From there you keep doing that until you have all of your walls laid out and that is how we will do it for each and every wall in this home.

8. Wall Types and Legend Usage

So now, as we come back over to here, you can see that this is gonna get new 2×6 wall here, new 2×6 wall all the way along the outside. Interior 2×4 wall is new, and then over here, all of these walls are nothing but white lines because all of this is existing.

We have a floor plan general note section as well, which will tell you different things such as all plumbing walls should be 2×6 minimum framing. Provide R-13 minimum insulation at plumbing walls. All of this is info that may be needed. As far as our framing goes, there’s only a couple things we’re actually going to take away from this.

9. Architectural vs. Structural Details

Now, like I explained to you guys, architectural tells you exactly where everything’s going to be placed as far as the toilet goes, these sinks, showers, kitchen island, washer/dryer, so on and so forth. None of this to do with framing, so we’re gonna go ahead and skip through this. If you have any interest, you guys can pause it and read it.

Now, when we get to structural, you’re gonna notice that nothing’s numbered on there. You have to go off the architectural floor plan to figure out where all of your other walls are gonna be, along with where your window and door openings are.

10. Elevation Plans and Exterior Views

The same thing is below. You guys have your kitchen laid out here, kitchen cabinetry here. Looks like a little stove there, sink goes there, bathroom is in here, sink, toilet, tub. Everything is laid out. The architect gives you info and all that, and as you can see, the reference points for everything for your key notes over to the side.

None of this has to do with framing. Only thing we take from this is your grid lines, all of your layout marks here for marking the center of your windows and your doors. That is it when it comes to framing.

11. Skipping Electrical and Mechanical Sheets

• This is first floor reflected ceiling plan.
• This has nothing to do with us.
• You have an L here for your lighting, a couple dollar signs, another crap for electricians.
• We don’t need to know anything about that whatsoever.
• Therefore, we’re gonna keep on truckin’, just so you guys can see it in case you’re curious.
• So, we have electrical symbols here, ceiling plan sheet notes, mechanical notes, lighting notes.
• No disrespect to you guys though, have much love for all other trades.

12. Roof Plans and Elevation Details

This is the roof plan here that how to read construction blueprints, architectural 2.5. This doesn’t give us too much info either. It says here that our slope is 1 in 12 going that direction downward, quarter-inch to 12 for our deck going that way. We already knew that info though.

Not much for us here. Holy moly, well onto something that actually makes sense—exterior elevations A3.0. As you can see here, we have East elevation. As you can see it from one side, North elevation, you can see it this way, and we’ve got these as well.