Blueprint Appreciation Post

Technical drawings are the thing that made this Hogwarts project possible, full stop. I don’t remember which of these was the correct order of events:

  1. I stumbled upon some blueprints online and thought, Wow, I could actually do a 3D model investigating the changes!
  2. I thought, Wow, I’d really like to do a 3D model investigating the changes! and subsequently found some blueprints online.

But either way, I don’t think I ever would have started this thing without some floor plans to guide me.


For the first film, I’ve got two different scans of a single plan of the miniature. One is a high-res B&W scan; the other has much lower resolution and a tighter crop, but it’s in color. Interestingly, their perspectives don’t match, suggesting that one or both of them may have actually originated as photos, not scans. But regardless, here I’ve tried to align them together, applying the low-res color data to the high-res scan. I’ve also rotated it (to match the plans for the other films) and corrected the perspective.

I have a few observations. First of all, this is evidently the fourth revision, dated January 14th, 2001, but there were likely other revisions after this. I say that because this plan is not completely accurate. Flaws I’ve noticed:

  • The Great Hall balcony has the wrong shape – the corners are square and it doesn’t wrap around the north side of the structure.
  • The training grounds tower doesn’t indicate the circle tower where it meets the Durham courtyard structures.
  • The quad interior has the wrong dimensions.
  • The walkway along the east side of the quad exterior appears to have a single level, and the elevation is marked as (I believe) 220′. This is the same level as the adjacent stone bridge. The final design for the first film moves the walkway lower down, with the part nearest the bridge even lower still. This also calls into question the accuracy of the area north of the quad, for which I sadly have no adequate photo reference.

Still, this is an absolutely invaluable look at the original castle.


Sadly, I have no floor plans for the miniature in the second or third films. I very much appreciate Warner Bros. posting these Prisoner of Azkaban elevations at the Studio Tour in London, though:

These cover many of the main changes to the castle in that film, and they were the reason I started my project with the Azkaban castle.


Goblet of Fire is an interesting one. I do have one partial floor plan, but the whole Great Hall/boathouse area is all wrong, as is the quad interior. I suspect that one wasn’t the final revision either.

As you can see, this consists of two scans or photos overlaid on top of each other. This composite I did not do – this is how the image was posted by user “decat” at the RPF.

This drawing provides evidence for the quad cloisters still existing in POA. Presumably, they were still part of that version, and at the time this drawing was created, they simply hadn’t yet decided to raise the quad, add the new arch, remove the cloister and fountain, etc. This is also the only plan I have of the training grounds tower from the COS redesign, and of the adjacent pathway that would eventually change in HBP.


I have no drawings of the miniature from OOTP. Fortunately, not much changed, and the changes that did occur will be easy enough to replicate with help from photogrammetry measurements.


The final HBP floor plan was actually released by Warner Bros. in the book Harry Potter: Page to Screen. It’s a two-page spread, which is wonderful for being able to read all the writing, but it does put an unfortunate seam right in the middle:

Still, it’s a fabulously detailed view of a critical production document and I’m grateful for it. I’m not aware of any inaccuracies here.

The same can almost be said of the earlier version on display at the Studio Tour:

The odd tapering crop is the result of perspective correction, since the original photo was taken at an angle. Note the lack of even the small HBP training grounds tower, the dotted outline of the old DADA tower to be removed, and the more detailed plan of the new astronomy tower.

If that’s not enough for you, though, don’t worry – when it comes to the astronomy tower, MTV News has your back! (Of all sites!)

I haven’t built the astronomy tower yet as of this writing, but this drawing is going to make it a cinch.


The main DH floor plan has also been officially released, albeit with some photo overlays that obscure some of the writing:

That film’s substantial changes are on full display here. The Fantastic Beasts castle is virtually identical; if they did create any drawings for that one, I haven’t seen them.


The real danger in studying these closely is that they refer to all the countless detail drawings that have not surfaced, and likely never will. Always leaves me feeling like the proverbial mouse for whom that cookie was simply not enough.

But ultimately, there’s a real beauty in all these drawings, even if I always find myself wanting more. I’m grateful to the deeply skilled drafters who brought these to life, and to the folks who’ve made them available to us fans!

Continuing the Curtain Walls

Relatively short post today. We’ll start off with some orthographic views of the POA model, by request. This is the state of the model before the progress you’ll see later in this post.

I always enjoy these blueprint-style perspective-less views.

Anyway, onward to today’s update. Let’s start fleshing out the remaining walls surrounding the training grounds! I’m kinda doing the COS version, since most of this is covered by a new hillside from POA onward, but that’s okay.

I hadn’t touched this area since late March 2019…crazy to think that it’s now been over 2 years since I started this whole project!

There’s not a lot of reference for this area of the miniature, but I have found some shots. Between those and photos of the real thing at Alnwick Castle, I think my results are pretty accurate. Interestingly, that guerite (small lookout tower) closest to the camera seems to have been slightly redesigned partway through the construction of the model. I’ve gone with the final design that was glimpsed – if only barely – in the films.

The next structure along the walls is Alnwick Castle’s barbican and gatehouse. (This is the building from which Neville falls and breaks his wrist in the first film.) I had already done a bit of work on this structure as part of an early attempt at recreating Alnwick itself – here’s an old render from this post:

I built this to the same scale as the main Hogwarts model, so it was easy enough to drop that into place and add brick textures:

As we’ve seen with other areas, I’ve built the walls so they go quite a ways down. From this view inside the training grounds, the lowest parts will eventually be covered up by grassy lawns. But on the outside, the terrain is rocky and uneven, and in some areas it slopes downward to reveal the lower areas of the wall. It’s easiest to just make the walls really deep and then cover a lot of it up with the terrain later on.

Fortunately, there are some nice orthographic drawings of the barbican/gatehouse structure on a placard at the location. These provide some very helpful reference. As always, my goal is to capture at least one of these, in roughly descending order of importance:

  1. The onscreen appearance and imagined reality of the castle in the films (which is achieved through a mixture of location shoots, miniatures, CGI, etc.)
  2. The main 1:24 scale VFX miniature of the whole castle
  3. The corresponding real-life filming location

These do not always agree, and there are significant gaps in the reference for the first two, so finding the right compromises can be tricky. For instance, this shot in Sorcerer’s Stone shows Neville’s POV as he nearly impales himself on a statue:

I’m not sure about the background, but the foreground architecture is all CG, and it matches neither the real-life location nor the miniature…although the corresponding spots at the location and on the miniature are never shown onscreen. To make matters worse, in the live-action location shots that follow, the statue (which I believe was installed just for the film) has moved to a different corner of the structure. So there is no single coherent reality for me to replicate.

In this particular case, my approach will be to ignore this quick shot altogether and aim instead for the real location with the added statues and other set dressings. But I’ll save that for the next post.