Episode Content

In a recent episode of the Digital Construction Podcast, we had a fascinating conversation with Tim Rawling, Co-Founder and Chief Product Officer at CalcTree . Tim shared his journey from working as a structural engineer at Arup to co-founding a startup dedicated to revolutionising how engineers perform calculations and manage their critical project data. He offered candid insights into the challenges of digitising a high-risk industry, the complexities of building software for engineers, and the transformative potential he sees in technologies like AI.

From Structural Engineer to Software: Tim's Entrepreneurial Journey

Tim's path to CalcTree began in structural engineering at Arup. He experienced firsthand the aspiration to digitise within large firms, but also the reality of how hard it is for big companies to digitise due to the high-risk nature of construction and internal resistance. Despite this, he found his way into digital work, building Grasshopper scripts and Python automations. Eventually, feeling constrained by the corporate environment, the Covid-19 pandemic served as a catalyst for him to take the leap and start something new in the construction space. Joining an incubator, Tim met his co-founders, and together they saw the potential to build a platform that could turn engineering work into reusable templates, addressing a key gap in how firms manage their intellectual property.

What's CalcTree

Tim described CalcTree as effectively a workbench for calculations. It provides a single environment where engineers can think through their work, execute calculations (like in Excel), and produce reports. A unique aspect is that every Calry gives engineers a web-based environment to quickly spin up code without complex installations. Critically, it is designed as a collaborative environment where team members can work together live on the platform. The ultimate goal is to enable engineers to turn individual pages or groups of pages into reusable templates for different projects, moving away from relying solely on shared spreadsheets.

Solving Fragmentation: The Industry's Biggest Inefficiency

The biggest inefficiency Tim witnessed in structural engineering, and believes is common across the industry, is the fragmentation of data across different tools. This multi-step process involves manually extracting data from one program, manipulating it in another (like Excel), and potentially moving it to others, which is incredibly time-consuming and often involves wrestling with different data formats. He stressed that engineers spend a lot of time manipulating data rather than actually designing. The most significant problem stemming from this manual handling is the extremely high risk of mistakes. CalcTree aims to solve this by encouraging engineers to lay out their calculations in a logical, documented way directly within the platform, making errors easier to spot.

Building Software for Engineers

Developing software for engineers presents unique challenges. Tim highlighted the internal saying at CalcTree about deciding whether to take a position on how a feature should work or give the user flexibility. While taking a position is technically simpler for software development, engineers often want control and get frustrated if they disagree with built-in assumptions or lack necessary information. Getting this balance right, ensuring the product is user-friendly without overwhelming complexity, is a constant and difficult challenge. Tim noted that engineers, especially those working under tight deadlines, have a low tolerance for complexity in new tools; if it's not intuitive, they'll revert to their familiar workflows.

Earning Trust Through Transparency

To address skepticism from engineers who are often rooted in traditional workflows (like Excel), CalcTree focuses on two key principles. First is transparency. Tim explained that engineers are wary of "black box" products where they can't see the underlying logic. CalcTree aims to be ultra-transparent, allowing users to view the integrations (like the Python scripts) directly within the page in a language they understand. Second is integrating with existing tools rather than solely trying to replace them. CalcTree learned that while ingesting Excel data was technically challenging, engineers often wanted to stay within their Excel environment. The strategy shifted to building high-quality plugins for Excel to bridge the gap, providing the benefits of a new software solution while accommodating existing workflows.

Evolution and the Road Ahead

CalcTree has evolved significantly since its inception, which started as a hardcoded calculation webpage. The product transitioned to enabling engineers to build their own templates in a no-code environment. The business model also shifted from an initial hope for product-led growth to a more focused B2B sales process to better engage with firms. Looking forward, Tim believes AI will be a major force in the next 5-10 years. He anticipates AI agents that can glue different tools together, directly combating the data fragmentation problem.

Key Takeaways:

  • Construction digitisation is challenging due to high risk and resistance, especially in large firms
  • CalcTree provides a collaborative workbench for engineering calculations, integrating reporting and scripting.
  • The platform allows engineers to create and reuse calculation templates
  • Building engineering software requires carefully balancing technical control and user flexibility.
  • Transparency and integrating with existing tools (like Excel) are key to adoption.
  • AI is expected to transform engineering software, potentially through AI agents connecting disparate tools.