Launch HN: Rudus (YC P26) – AI for concrete contractors

Hi HN, we’re Rishi and Sahil. We’ve developed Rudus (https://www.rudus.ai/), an AI-powered takeoff and estimation platform built for concrete subcontractors.

Takeoff is the process of measuring and quantifying materials from concrete plan sheets. Rudus identifies every concrete structure (footings, walls, columns, slabs), pulls in related details, and eliminates hours of manual quantity calculation. Here’s a demo: https://www.youtube.com/watch?v=PAMNDRWEdlI.

The problem: Concrete subcontractors are the backbone of every building, but their estimating workflow hasn't changed in 20 years. Right now, a senior estimator opens a PDF, manually traces every footing and grade beam, then hand-builds an Excel spreadsheet with 300+ line items- volumes, formwork, rebar by bar size with lap splices and development lengths. Bids can take weeks and even months. Most firms have just a few estimators, meaning they physically cannot bid on most of the work available to them.

The software incumbent in this trade hasn’t been updated since 2020. Beyond that, every AI takeoff tool on the market was built for GCs and treats concrete as one checkbox, rather than working around how concrete estimators actually price work. We’re building Rudus for this trade and only this trade.

We started this when Sahil took a construction management class and realized how the estimation workflows hadn't changed in decades. We started cold calling, walking into offices with donuts, showing up at job sites, and everyone told us the same thing: slow estimation is the biggest bottleneck in growing their business, but every new product they've tried has failed. We quickly realized that the reason those tools failed is a lack of trust and frequent errors causing later problems. Estimators stake million to billion dollar bids on these numbers, and they are clear that they won’t trade their workflow for a black box. We took a different approach: software that intelligently accelerates their current workflows rather than replacing it by forward deploying our product into their current estimation workflow.

When an estimator uploads their structural PDFs to Rudus, we auto-classify every sheet (foundation plans, section details, footing schedules, frame elevations) and route each to the right processing pipeline. Computer vision detects concrete elements across the drawing set and follows cross-references across sheets to resolve dimensions and detailing, catching elements that plan-only tools always miss. Each element gets expanded into full assembly line items: concrete, formwork, and rebar with all the calculations an estimator would normally do by hand. A typical foundation package goes from a handful of assemblies to 80-120 priced line items. The estimator reviews, overrides where needed, and exports straight into their existing workflow.

We have a couple key advantages in the AI estimation space. The first is our focus on concrete, a niche part of construction. No one else is building this for concrete subs because the sheets vary drastically from other subtrades. For this same reason, VLMs and other generic solutions don't work. Instead, proprietary computer vision models are required, relying on training from massive amounts of customer data. We run multiple different models trained directly on our customers' takeoffs, and every interaction from our customers with our models becomes a training example, allowing accuracy per client to sharpen with use.

Our second advantage is in our product methodology, as we’ve chosen to build a copilot, not a black box. Most AI takeoff platforms try to replace the estimator completely by autonomously producing quantities, but the quality of the outputs with current models is poor, so the takeoff gets redone by hand anyway. After 100+ hours sitting in rooms with structural concrete estimators and completing numerous takeoffs ourselves, we’ve built around their actual workflow. The estimator starts the takeoff, and Rudus extends the work across the sheet by finding similarities, following cross-references, and understanding callouts. The estimator stays in control of every accept, override, and edit. The result is faster takeoffs they can defend, not unreliable AI output they throw away.

We’d love to hear what you guys think about our demo video (https://www.youtube.com/watch?v=PAMNDRWEdlI) or your experiences building out computer vision models, or anything you think is relevant!

29 points | by rishipankhaniya 3 hours ago

9 comments

  • so_it_be 0 minutes ago
    I'll show you how to get rich if tommorow goes bad, f*cking PE - I want VC.

    The UK sucks.

  • asdev 1 hour ago
    I wonder if this approach to starting a vertical business the founders have 0 experience in has ever panned out. I know YC pushes the B2B SaaS angle as hard as possible, searching for "underserved" niches, but seems like if you don't have true industry experience, it can't possibly work out.
    • mbesto 4 minutes ago
      Travis Kalanick had zero taxi experience and Brian Chesky had zero hospitality experience.

      Now they created new models to existing paradigms, because I do tend to agree that founders that have verticalized experience tend to be far more successful (but perhaps arguably less 'disruptive')

    • conorplunkett 52 minutes ago
      Sad because I’ve been in construction for 6 years, have a degree in civil and built the exact same product. We applied for S26 but haven’t heard back, and I think we have more revenue than these guys. It’s kinda sad what YC is doing nowadays. They say they want founder problem fit but ignore it when it’s right in their face. https://buildwise-psi.vercel.app/
      • maxignol 21 minutes ago
        I know you don’t judge a book by its cover, but a vercel extension does not look professional nah ?
        • apsurd 12 minutes ago
          it’s a good point. Their product likely is legit, but i even judge individual contributors who use these site builders for their resumes or portfolios and stick with the subdomain. It’s that last mile effort towards completeness i think.
  • is_true 46 minutes ago
    A friend works in construction and they have details of how much materials each part of a construction needs. Most of it comes directly from the (not sure the name) SW they use to calculate the structure/ draw the plans.
    • andyfilms1 6 minutes ago
      I was going to say, I don't understand what this does that Revit doesn't already do better. I guess it's a fun demo, but this is not a problem that needed solving.
  • jessehorne 1 hour ago
    The tool looks sick. I think the copilot vs black box approach is great. I found the demo to be enjoyable and satisfying to watch despite having no experience in the concrete estimation industry.

    This is out of my wheelhouse but had a couple of thoughts. When you clicked P1, it found all of them. What happens if it doesn't? This would have been good to see in the video.

    Also, I'm sure people familiar with these documents will have no trouble but was thinking it could be cool to do some effect to make references glow/be more noticeable at least temporarily when you are skipping around to them. Maybe some zoom controls too.

    Anyways, good luck!

  • seebeen 40 minutes ago
    If the AI miscalculates, and building crashes and people die - who is held responsible?
    • layer8 26 minutes ago
      The plans are the input here, not the output. The AI prepares cost estimates. It isn’t responsible for what is getting built.
  • afzalive 49 minutes ago
    Looks like a useful tool but I don't know anything about construction.

    Love the transparent AI helper implementation though. I feel like you don't even need to say it's AI because it's so helpful but not in your face but maybe that's what people are searching for.

  • nzjrs 55 minutes ago
    Horiffic
  • flyingmiata3303 13 minutes ago
    [flagged]
  • themuskgpt2025 1 hour ago
    No, very helpful, inshaAllah, thank you. Assalamualaikum.