About us
Building estimating is all we do
Builder Expert exists for one reason: to give UK builders numbers they can trust, whether a professional prepares them or our software does.
Our mission
Estimating made for UK builders
We offer building estimating services and software made for UK builders who want to plan residential projects with confidence.
Construction estimating isn’t just about numbers, it’s about clarity, confidence and control. A good estimate wins the job, protects the margin, and keeps the project on track. A bad one costs real money.
That’s why Builder Expert Ltd focuses entirely on estimating for UK residential construction. Our estimators prepare itemised, client-ready estimates for extensions, conversions, refurbishments and new builds, and our software, BEX AI, puts the same discipline into a tool that drafts branded quotes in minutes.
Client satisfaction is at the heart of what we do. Every project is unique, and so should be your estimating solution, which is why we offer everything from a £90 next-day estimate to detailed, client-ready quotes and AI software you can run yourself.
What we stand for
Three things every estimate must deliver
Clarity
An estimate should tell you exactly where the money goes: every task, every material, every stage itemised so there's nothing to guess.
Confidence
Numbers grounded in live UK pricing and real residential workflows, so you can quote clients and plan projects without second-guessing.
Control
Your margin, your timeline, your decisions. Good estimating puts you in charge of the project before the first brick is laid.
What we do
Two ways we can help
Meet the founder
The person behind Builder Expert
Martin Pietrzyk
Founder, Builder Expert Ltd
I came to London in 2000, nineteen years old, fascinated by two things: technology and building. My first job was as a kitchen porter. I gave becoming a chef a go, but it never quite fit. A few months in I got a chance to work on a building site as a labourer alongside a tiler, and within a couple of years tiling had become my trade.
I always wanted to build something of my own, so I taught myself project management, took on bigger jobs (bathrooms, kitchen refurbishments, full decorating projects), and in 2005 I started my own construction company.
Running it taught me something no course could: estimating is almost a full-time job in itself, and it gets done after hours and at weekends. I was writing every quote by hand in Word while managing crews on site and chasing materials. So I did what came naturally, I tried to automate it. I built my first quoting system in Excel, every task listed and broken down by phase, so a client could actually read the estimate and understand where their money was going.
The more I used it, the more I improved it. I learned an estimate has to be written in the client's language, not engineering jargon, and structured so it never fights with the payment schedule, so a builder can add or drop tasks without the whole thing falling apart. I kept growing the task library, and eventually hired an assistant to run the system, which finally gave me my evenings back.
Then my subcontractors started asking me to prepare their estimates too. That's when I realised the system was worth more than my building company. I'd always loved software, and this was the moment programming was going mainstream, so I made the call: I stepped back from construction to focus on what combined both of my passions, technology and building.
In 2018 I founded Builder Expert. Today that early Excel system has become BEX AI, estimating software that does in minutes what used to cost me my weekends, while our team still prepares estimates by hand for builders who'd rather hand it over. Same principle I started with in 2005: give builders numbers they can trust, in language their clients understand.
Have a project that needs pricing?
Tell us about it, and we’ll recommend the right service and get you a clear, itemised estimate.