# Monumental — Autonomous robot fleets for on-site bricklaying.

Monumental builds and operates compact autonomous robots that lay brick and mortar on live construction sites. Its Atrium software coordinates fleets from a digital model, and the company sells finished masonry work as a subcontractor rather than selling robots.

Founded

2021

Headquarters

Amsterdam, Netherlands

Category

Robotics, Hardware, B2B

Legal name

Monumental B.V.

## Highlights

Notable milestones from Monumental’s journey — funding rounds, launches, and other moments worth knowing.

Funding - Jul 2026

### $32M Series B backs US expansion after 100+ homes

Khosla Ventures led the round, taking total funding to $59M. Monumental said its fleet had built more than 100 homes plus a school, community center, hotel and canal walls across the Netherlands and UK; the capital funds more European deployments, a US launch and a wider range of construction work.

Round

Series B

Raised

$32M

Led by

Khosla Ventures

**Co-founders Salar al Khafaji and Sebastiaan Visser with Monumental's construction robots.**

[Source](https://www.monumental.co/press/announcing-our-32-million-fundraise)

Milestone - Dec 2025

### A robot fleet runs a 36-hour nonstop build

Monumental kept its robots laying brick for 36 hours straight on a transformer-substation project with Waal, its first continuous day-and-night build. The same job also produced the fleet's first soldier courses, adding upright bricks to its supported masonry patterns.

[Source](https://www.linkedin.com/posts/salark_a-couple-weeks-ago-we-ran-our-first-24h-activity-7407392198272491520-GQVm)

Milestone - Jun 2025

### Five robots complete all brickwork for an eight-home block

A five-robot fleet laid every brick, including the corners, for eight homes at Kreekrijk in Assendelft. Monumental and masonry partner Koedooder described it as the first housing block fully brick-laid by robots.

**Five robots worked together across the eight-home block at Kreekrijk.**

[Source](https://www.linkedin.com/posts/salark_its-so-exciting-to-see-our-vision-become-activity-7344282834993393665-b1GP)

Partnership - Apr 2024

### A three-robot crew lays walls at a live healthcare project

At SEIN's new epilepsy and sleep-medicine activity center in Cruquius, the bricklaying robot worked from the building's digital 3D model while two autonomous vehicles supplied mortar and bricks. The pilot put Monumental's coordinated fleet into an active build with contractor Pellikaan.

**The SEIN pilot paired one bricklaying robot with two autonomous supply vehicles.**

[Source](https://www.sein.nl/nieuws/2024/bijdrage-aan-innovatie-metselrobot-in-actie/)

Funding - Feb 2024

### Emerged from stealth with $25M for autonomous bricklaying

After two and a half years in stealth, Monumental showed a compact three-robot system: brick and mortar carriers feeding an autonomous bricklayer that navigates ordinary construction sites. Plural and Hummingbird co-led the round to scale manufacturing, deployments and supported masonry tasks.

Raised

$25M

Led by

Plural, Hummingbird

**Monumental designed its robots to fit ordinary construction sites rather than requiring factory-like conditions.**

[Source](https://www.monumental.co/posts/announcing-our-25-million-fundraise)

Team - Jul 2021

### Silk's founders reunite to automate construction

Salar al Khafaji and Sebastiaan Visser founded Monumental in Amsterdam after building data-visualization startup Silk, acquired by Palantir in 2016. They chose a vertically integrated stack of robot hardware, software and machine vision, operated as a masonry subcontractor.

[Source](https://www.monumental.co/about)