Developer for construction and building physics softwareAvailable now
Engineering calculators your customers can actually use.
For Bunch Bygningsfysik I built a moisture content calculator for construction compositions. Their calculation module already had years of building physics expertise baked in, so I kept it as the engine and put a modern, easy to use web UI on top instead of rewriting what worked. That is the shape of most construction tech work: deep domain logic that deserves a better interface.
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Is this a fit?
An honest fit check before we talk
I would rather tell you no on the first call than waste your budget. Here is what a good match looks like in this sector.
A good fit if
- You are a construction, engineering or building physics company with a calculation tool, spreadsheet or legacy app that needs a modern web UI.
- You build software for architects, engineers, contractors or building owners and need a developer who respects the domain logic.
- You want to turn in-house expertise into a product customers can use online.
- You need dashboards, reporting or project tools that handle technical data without confusing non-technical users.
Probably not a fit if
- You need a structural or building physics engineer. I build the software around your experts.
- You need BIM tooling, CAD plugins or 3D modelling. Not my field.
- You need a field app with heavy offline mapping and hardware integration beyond what Expo handles well.
What I do
What I typically build in this sector
- Web UIs on proven engines
- Keep the calculation logic that works, wrap it in a clear, fast web interface with validation, explanations and exports. Built in React or Vue with TypeScript.
- Calculators and configurators
- Input forms for compositions, materials and parameters, with results that update live and outputs your customers can hand to a client.
- Project and reporting tools
- Internal and customer portals for projects, documents and reports, with roles and permissions.
- Mobile companions
- iOS and Android apps with Expo for use on site, sharing code and APIs with the web tool.
Proof
Clients who kept me around
A building physics calculator, a climate footprint tool and a regulated pharma environment. Different sectors, the same respect for the domain.
Bunch Bygningsfysik
Full-Stack Developer · Freelance
Built a moisture content calculator for construction compositions. Their existing calculation module already had years of building physics expertise baked in, so I kept it as the engine and put a modern, easy to use web UI on top of it instead of rewriting what worked.
Read the case studyMålbar
Full-Stack Developer · Freelance
Ongoing development for a Danish life cycle assessment company. I have helped build their LCA screening tool, which lets companies estimate the climate footprint of their products, along with the internal tooling the team runs on every day.
Read the case studyY-mAbs Therapeutics
Full-Stack Developer · Freelance
Full-stack development of web solutions for a commercial-stage biopharmaceutical company, a regulated environment where reliability, correctness and clear documentation are not optional.
Read the case study
Process
How we'll work together
The same four steps for a two-day fix and a two-year engagement.
Intro call
A free 30-minute call where you tell me about your project, goals and constraints. I ask a lot of questions and tell you honestly whether I'm the right fit.
Proposal & estimate
You get a short written proposal: scope, approach, timeline and price. Fixed price for well-defined projects, hourly or retainer for ongoing work.
Build in the open
Short iterations, working software early, and a weekly update you can actually read. You see progress and can change course before it gets expensive.
Launch & support
I handle deployment, hand over clean documentation, and stick around for support and further development if you want me to.
FAQ
Questions I get asked
- What have you built in construction tech?
- A moisture content calculator for construction compositions for Bunch Bygningsfysik. Their existing calculation module stayed as the engine, and I built a modern web application on top of it so their customers can use it without a specialist in the room.
- Can you work with our existing calculation code or spreadsheets?
- Yes, and I usually recommend it. Domain logic that has been validated over years is worth keeping. I put an API and a modern UI around it and only rewrite the parts that genuinely need it.
- How quickly do you learn our domain?
- Faster than most, because I ask a lot of questions before writing code. I have picked up LCA methodology, building physics, bookkeeping rules and pharma processes on previous engagements. Expect me to be useful in the first week and fluent in the domain within a month or two.
- How do you price work?
- Fixed price for well-defined projects, hourly or a monthly retainer for ongoing work. My preferred engagement is 20-40 hours a week for six months or more. Rates are in the proposal, not on the site.
- What happens after launch?
- I stick around. My clients have kept me for one to six years, first for the build and then for support and further development, usually on a retainer of reserved weekly hours.
- How quickly can you start?
- Current availability is on the homepage. If it says available, usually within one to two weeks after a free 30-minute intro call and a short written proposal.
Contact
Tell me what you are building
What it is, roughly when it needs to exist, and what a great result looks like. I usually reply within a day, and the first 30-minute call is free.
hello@perhp.com