I’m A Celebrity… Get Me Out of Here! – Castle Survey

We were recently commissioned by ITV to survey the now famous Gwrych Castle for “I’m A Celebrity… Get Me Out of Here!” 2020. Now one of the most recognised buildings in the UK, it was a great opportunity for our team and a once in a lifetime chance to be a small part of the most watched program on TV.

The Call

Back in mid-July this year, I was close to not taking the call that led us to this fantastic project. I was working from home and had received only cold sale calls all day. With the route from my office to the phone involving a small dog and a staircase, I’m sure you can understand it can be quite Hazardous!

Ignoring the dangers, I braved the route, desperately hoping it would be worthwhile:

Price Needed for a Big Castle, Somewhere

“Hi James, it’s Emily. I’ve seen the video of the Stone Church you surveyed in 3D. Unfortunately, I can’t say too much as we’ve signed a pretty strict NDA, but, we need you to survey a castle. We can’t say where, all we can say is, it’s a pretty big castle and you will have 2 and a half weeks to produce an accurate 3D model of it for us. Is this possible?”
*Disclaimer – My memory is shocking. So, if you are reading this Emily, just assume that is exactly what you said 😉.

Completely ignoring the panic that started to creep in, I of course gave the answer: “Sure, no problem”.

A few days later we signed the NDA and were given the Castle Location. Noting ITV’s name in the header, we could only assume it was for a new Drama of some sort, maybe even a new outing for the Coronation Street crew.

I'm a Celebrity - Gwrych Castle - July 2019

The scope

To create an accurate measured building survey in 3D, suitable for Sketchup. This would allow the design team to figure out best use of space and concentrate on creativity, rather than spending their time on surveying the existing environment.

The general requirement was to create an accurate 3D model with simple detail, up to the first 10 feet from ground level. However, any details that could be captured at high level, would serve further visualisation purposes later in the project.

Timescales were tight, so rapid data capture and delivery was essential.

The team

  • Portrait Peter Hooley Scanning / Revit Surveyor
  • Portrait Charley Lawrence Data Processor / Surveyor
  • Portrait James Pegg Drone Pilot / PM

The Plan of Action

Gwrych Castle has expansive Ramparts buried in the hillside making it very difficult to survey quickly. 2.5 weeks was looking much tighter now I could see the extent of the task.

Traditional Survey methods such as tape and disto were completely off the table! The only way to quickly capture accurate measured data of the intricate stonework would be to laser scan it to create a point cloud (100’s of millions of accurate 3D points, look at it from a distance and it looks like a cloud…. point cloud). This would at least get us everything visible from ground level. The trickiest part was tackling the lack of stairs and access to higher levels.

Where did all the Stairs go?

This wasn’t just a Castle; it was pretty much a ruin! All that remained in terms of access, was the odd staircase that lead to nothing (other than a nasty fall) and some very high, somewhat vertical walls. The only option to capture clean detail at high level, was to deploy our drone and some well-practiced photogrammetry techniques (The art of stitching lots of photos together to make a 3D model). Using these methods, we believed we could capture the whole Castle intricately, in just 2 Days!

3D Castle in SketchUp

The end output needed to be in Sketchup. Luckily, only a simple level of detail was required to enable our clients to carry out their design work. Sketchup is a great tool for interior designers and people wanting to mock-up ideas for small buildings. But, it has never really been the go to software to help design Castles. Generally, it does not like big, complicated geometry without military grade hardware to power it. So, we needed a way to simplify the point cloud and drone data.

I'm a Celebrity Drone view Gwrych Castle
I'm a Celebrity Gwrych Castle, view from above

Point Cloud to Revit to SketchUp

Working with Point Clouds in Sketchup is very difficult. They are huge files, and in this case, the external scans alone weighed in at just over 54 Gigabytes (Roughly the size of 54 full movies)! We could simplify this huge data set by interpreting the major walls and low-level windows in AutoDesk Revit, allowing us to create simple geometry in a software that can handle the point cloud well.

Reverse Engineering from Point Cloud

By strategically reverse engineering from the point cloud data, we can create a much lighter weight 3D model with a file size of just 15 Megabytes (About the size of 3-4 pictures taken with your smartphone)! We can then export to a standard Sketchup file.

I'm a Celebrity Gwrych Castle - Point Cloud to Revit Analysis
I'm a Celebrity - Gwrych Castle - Revit Survey Tower

Drone Data to 3D Poly Model to SketchUp

Getting from point cloud to Sketchup is a well-known and practiced workflow. However, converting drone imagery into an accurate 3D model is less so. In fact, I even joined a few of the biggest Sketchup user groups on Facebook and Linked-in to see if anyone there had found a way. Unfortunately they hadn’t, meaning, we needed to break new grounds and come up with something completely out of the norm.

3D OBJ Models

We knew that we could create very detailed 3D models in obj format from the drone imagery. This is already frequently utilised in the high-end film and gaming industry to capture environments for use in CGI (Computer Generated Imagery). By combining with the point cloud data, we could also build in a level of accuracy. This had to be our first step! However, the resulting model even in a low-resolution format, was made up of over 80 million triangles (or polys as they are commonly referred to). According to the Sketchup forums I had infiltrated, Sketchup liked a maximum of around 200k!

Decimating OBJ for SketchUP

Using some old, researched knowledge, we knew it was common for game developers to “decimate” their detailed models, so that they could display objects without eating up the computer’s memory. This had to be the next step.

It was a little disheartening to watch the detail slowly drip away as we continued to half the number of triangles, but we knew this was the sacrifice that had to be made to get the 3D model to a usable point. Now it was a simple case of finding an importer plugin for SketchUp to allow us to convert the obj to a usable SketchUp format.

A Charming Result

Although it didn’t look quite as realistic as the original 80 million triangle predecessor, I hope you agree, it still has a certain amount of charm.

“These models are super handy.” was one of the comments from our client when we handed them over.

I'm a Celebrity Gwrych Castle OBJ to Sketchup

Is this for I’m a Celebrity???

We first started to think that the work was possibly for “I’m a Celebrity… Get Me Out of Here!” when WalesOnline published this Article in early August, that the show would now be held in the UK. The NDA we had signed was for ITV, so we thought there might be a small chance, after all it would make a great setting: No roof, cold floors, likely haunted, but with a beautiful view and plenty of random areas for tasks! This would be perfect for I’m a Celebrity.

The Sun finally confirmed our suspicions and issued their article towards the end of August revealing the new setting for I’m a Celebrity… Get Me Out of Here:

I'm a Celebrity - Gwrych Castle - July 2019


We are so used to surveying buildings for property developers or Architects, and gradually seeing our work used over the following years as design and construction takes place. But this was an entirely new world for us. We handed our work over in August and just 3 months later saw a totally transformed castle with over 14 million viewers tuning in to watch I’m a Celebrity… Get Me Out of Here, seeing our efforts put to such an amazing use. It brings an element of pride and has been a highlight to the careers of all our team that took part.

What our Team thought

Here’s what some of our guys had to say when I asked them the question: “How did surveying the I’m A Celebrity Castle make you feel, what emotions did you have when you knew what it was for?


“I mean I really enjoyed it anyways, like it was a gorgeous place to be regardless of I’m a celeb… BUUUUT I’ve watched that show since I was a kid, so when we found out that it was for I’m a celeb, it was pretty awesome for me. 😊

Charley Lawrence – Surveyor


“I was amazed when I found out what it was for after watching it for so many years. I felt so privileged to be part of a small part of such an iconic TV series”

Peter Hooley – Surveyor

A Testimonial from our Client

“The work You and The Team carried out really did form the framework and backbone for our design. With such a tight timeframe, your service freed us up to concentrate on the design and function of the set rather than weeks of survey and draughting.”

Mathieu Weekes – Bizibot


We’d like to thank ITV and the “I’m a Celebrity… Get Me Out of Here!” team for this fantastic opportunity and hope to be working with them on more projects soon.


Get in touch