UK Region Pack - Developer Diary

Written by pdx_Peanut with the help of Macwelshman and Rik4000

Introduction

Hey everyone, welcome to this week's dev diary! It’s Pdx_Peanut here, and today I’m excited to take you behind the scenes on the creation of the UK Pack, brought to life by the amazing creators Macwelshman and Rik4000!

You can download the amazing UK Region Pack now, for free, on Paradox Mods; https://mods.paradoxplaza.com/mods/92859/Windows

Both creators are well-known for their Cities: Skylines workshop contributions - Macwelshman offering a beautiful mix of UK and American buildings, and Rik4000 capturing everything quintessential about UK cities and suburbs. They’ve both been part of the community since the early days of Cities: Skylines back in 2015, and it’s wonderful to see their legacies continue into Cities: Skylines II. When we set out to create a UK Region Pack, they were the natural first choice to bring on board!

Concept and Inspiration
Having seen their previous work, I knew I could trust both creators to bring the perfect sense of realism to the pack, and they exceeded all expectations. They started by meticulously researching iconic buildings and everyday structures from across the UK, seeking out the most representative examples to use as inspiration. Their goal was to strike a balance between showcasing the UK’s rich architectural history and offering a wide range of styles that would feel authentic in various settings. From the elegance of Georgian and Victorian architecture to the distinctive designs of the 1930s and the contemporary styles of the 2000s, they worked to ensure the pack captures the essence of the UK’s architectural diversity in every detail.Examples of architectural inspirations across the pack.

Making the Assets

Service Buildings

One of my favourite buildings in the pack that we can take a closer look at is the UK Hospital General Infirmary. As the main hospital asset for the pack, it truly commands center stage in any UK city build. Inspired by the Victorian-era General Infirmary in Leeds (pictured above), this building brings a historic yet timeless presence to the pack, blending classical design with the practical needs of a modern healthcare facility.

Bringing the building into the game involves several stages of planning. First, you need to block out the 3D design by modeling simple shapes and layouts to determine the overall scale and size. Here, we can see the team working through different initial designs, testing whether the architectural features of the inspiration building are accurately captured. They also experiment with gameplay elements, such as the placement and configuration of upgrades, to ensure the building not only looks great but will also function well within the game.Initial concept models of the General Infirmary

Once the overall design is finalized, the creator moves on to refining the model by adding intricate details. This includes architectural features such as doors, windows, window frames, decorative trims, and other smaller elements that help breathe life into the asset. These details are crucial in capturing the building’s authenticity and ensuring it feels grounded in the world of the game. Below, you can see the next iteration of the more detailed model - modeled in Blender - where the added features start to bring depth and realism to the structure.

Additionally, the first textured version of the building is shown, where - using Adobe Photoshop - the carefully chosen materials and colors, such as stonework, brick, and other period-specific finishes, are created and applied. This gives the building a tangible, lived-in appearance. At this stage, the final asset begins to emerge - not just as a model, but as a centerpiece for the pack.UK Hospital General Infirmary modeled details and texture creation.

Propping a large building like the General Infirmary can be a lengthy and repetitive process in the early version of the asset editor. In the screenshot below, you can see how crucial it is to consider pathfinding, ensuring that all props requiring path access are properly connected with routing. This ensures that vehicles and pedestrians can navigate around and interact with the props effectively. Additionally, each prop has its own probability slider, allowing creators to determine the random chance of the prop appearing when the building is placed. This adds an element of unpredictability and realism but also requires precise adjustments for a well-balanced outcome - if a creator always wants a prop or tree to show up, they have to change the probability to 100.

Beyond just the props, the creator must also manually place all the functional markers. This includes door markers, access markers, markers that allow ambulances to spawn and despawn, fire effect markers, sound effect markers, and lighting props. Each of these markers serves a specific function, ensuring the building operates seamlessly within the game world. The process can easily total hundreds of mouse clicks, as each marker must be placed with care to ensure the building not only looks authentic but also performs as intended in the game’s simulation.Propping the UK Hospital General Infirmary

Zones

With the wide range of styles, the pack is rich with different kinds of zone types, and we decided to create more specific zones within the same density demand where it made sense. This approach allowed us to offer more distinct "flavours" of buildings for players to choose from while still ensuring they fit within the base game’s zoning density design. This way, players can enjoy a greater variety of buildings that feel unique yet remain consistent with the game’s overall zoning structure.

UK Low-Density Detached Housing - Low-Density Residential Demand

This zone represents your standard low-density housing option, allowing a single household to move in. In the UK, this type of housing is commonly referred to as a detached house, and the creators of the pack were keen to include this terminology to enhance its authenticity.

The houses in this zone span a variety of eras, ranging from the 1930s to the 2000s, with some of the larger lots featuring Victorian-styled dwellings. This variety reflects the different types of detached houses you’d typically find in the UK, giving players a realistic representation of the country’s suburban landscape over time.

Below, you can see a planning image of the zone’s lot propping progression through the levels, starting with level 1 on the left and moving to level 5 on the right. The idea is that, as the building evolves, the lot and house gradually gain additional elements that suggest an increase in the occupants' wealth. This might include features like more elaborate landscaping, upgraded materials, or added details that reflect a higher standard of living over time.Planning Low Density Detached Housing Propping

Medium Density Residential Demand

The medium residential demand category offers the most diversity in zone types. The first style you’ll see is the standard UK Medium-Density Housing, which provides small apartments for your citizens. The building styles span several decades, primarily from the 1950s to the 1980s, with a few examples dating back to the 1920s. The number of households available per building is similar to the base game variants of the medium density housing.Planning evolution of Medium-Density Housing

The next medium-density zone is the UK Medium Density Semi-Detached Housing. While this zone is technically still medium density, it acts as a step up from the low-density housing zone. Rather than accommodating a large number of apartments for multiple households, each building in this zone provides housing for exactly two households - just one more than the low-density option. This setup offers a balance between density and space, reflecting a common housing style seen in many UK suburban areas.Final Propped Semi-Detached Houses

The next zone in the medium residential category is UK Medium Density Terraced Housing. Back when the pack was first planned, we weren’t sure of the way the Medium Row Housing zones would work, so while these buildings are designed to be similar in functionality, we opted to have a slight difference in the way they behave.

During development, we quickly realized that UK terraces are rarely as wide as 8 meters (1 game unit). To stay true to their proportions, we designed assets that have 3 or 4 realistically sized households within a 2- or 3-unit-wide lot, carefully controlling the number of available households to ensure the design stayed faithful to the authentic layout of traditional UK terraces.

Finally, for medium density, we have UK Mixed Housing - which utilizes custom storefronts in UK-themed apartment buildings, giving you that balance between residential and commercial zoning.

High Density Residential Demand - UK High-Density Housing

This zone represents the quintessential high density towers found across cities throughout the UK. Styled as a blend of inner-city general UK architecture and Victorian housing estates, these buildings offer a mix of modern high-rise living with elements that reflect the rich architectural history of the country. The design captures the urban character of densely populated areas while also maintaining a link to the past through its historical influences. Below, you can see the propping evolution of these housing estate towers.Planning High-Density Housing level progression

Signature Buildings

The UK pack also includes a wide variety of signature building assets, covering residential, commercial, and mixed zones.

In the residential tab, you’ll find the Executive Mansion and UK City Apartments. Let’s take a closer look at the Executive Mansion. Inspired by a presumed Georgian-style mansion the team found during their conceptual-stage hunt for architectural inspiration, this building captures the stately elegance of classic British architecture. The creators paid special attention to intricate details, such as the ivy growing on the facade. They used alpha cut-out texturing to achieve a layered effect, making the vegetation appear natural and realistic.Comparison of real-life and game versions of the Executive Mansion.

For commercial signature buildings, we chose a range of classic Welsh and English-inspired pubs. Each style comes with three variations, giving you the option to choose between a small, compact version or larger versions that offer more parking space and additional features. These variations provide flexibility, allowing players to select the best fit for their city’s layout, whether they need a cozy local pub or a larger, more prominent establishment with room for more patrons and vehicles.

But it's not just pubs included in the commercial section—there’s also a range of country hotels, petrol stations, and a large, quintessentially British supermarket: Morrissey’s Supermarket! Each of these buildings was chosen to represent essential elements of British life, offering players a variety of options to enhance their city’s commercial areas. A comparison of the differences between meshes on the Country Hotels.

Props

Props were a relatively late addition to the packs due to uncertainty about the readiness of the import pipeline to support them. This is why not all Region Packs include custom props. However, when the opportunity arose, the UK team eagerly embraced it, as they had been keen from the start to use custom props to bring an extra layer of authenticity to their buildings. Fast-forward to the finished product and the pack now boasts an impressive 135 custom props, with 78 of them available in the recently added props menu - 76 categorized under residential props and two under commercial props.Examples of the range of styles of wall props used across the UK Pack.

Challenges and Iterations

One of the biggest challenges the UK team faced while creating and finalizing this pack was the immense amount of hard work required. The pack is expansive, and every single building and prop had to be crafted from scratch, including custom meshes and textures. Each asset then had to be individually imported into the game’s editor, a time-consuming process in itself.

On top of that, all buildings had to be meticulously hand-propped. As mentioned earlier with the Hospital General Infirmary, this involved manually adjusting prop probabilities and finely tuning their positions and alignments. It’s a detailed, labour-intensive task that requires patience and precision to ensure everything looks and functions as intended in the final product.

The Beauty Shots

That’s it for today’s diary! We hope you enjoyed this behind-the-scenes look at the creation of the UK Pack and all the details that went into making it authentic. Thanks for joining us, and we can’t wait to see the amazing UK-inspired cities you’ll build!

Please enjoy some images of our favourite assets below:You can download the amazing UK Region Pack now, for free, on Paradox Mods; https://mods.paradoxplaza.com/mods/92859/Windows


In two weeks, we travel the furthest we have yet! We head off to Japan!