Home extensions for more living space
Want more living space in Rotterdam? A home extension enlarges your house without you having to move. We take care of the whole project: foundation, structure, roof, window frames, insulation and the interior finishing. One dedicated team, one point of contact and a clear price agreed up front.
Extra space that blends seamlessly into your home
A home extension is a genuine structural undertaking: the foundation has to be right, the structure safe, and the connection to the existing house watertight and free of cold bridges. As a dedicated construction company in Rotterdam, we handle that entire process with one team, from groundwork to the final finish.
Whether you want to enlarge the living room, add a garden room or extend the kitchen: you receive a clear quote with a transparent price breakdown up front, we handle the permit application if needed, and we deliver turn-key. That way your home grows with your wishes.
Request your free extension adviceOne dedicated team
Our own craftsmen, one point of contact, no miscommunication.
Clear price up front
A clear quote, with no surprises afterwards.
Guaranteed & certified
A guarantee on our work, plus CO certification, STEK, NEN 1010 and VCA.
Local in Rotterdam
Familiar with Rotterdam's homes and the local council.
Recent projects in Rotterdam and the Randstad
A selection of our completed projects. View the full portfolio for more.
What our clients say
We only publish genuine, verified reviews. Our clients' reviews will soon be shown here via Google.
What a home extension involves
An extension is groundwork and finishing alike. We take care of every trade, in the right order.
Foundation & concrete floor
Groundwork, an insulated foundation and a strong concrete floor as the base.
Structure & steel
Brickwork, timber frame or a steel load-bearing structure, safely engineered.
Roof & waterproofing
The roof structure and a watertight connection to the existing house.
Window frames & insulation
Window frames, HR++ glazing and insulation for comfort and low bills.
Interior finishing
Plastering, flooring, electrics and painting, neatly finished.
Part of a larger renovation?
Combining your extension with a full home renovation? We arrange that too.
How we build your extension
A tight process in five steps, from design to handover.
Design & permit
We visit, think along with you about the layout and, if needed, handle the permit.
Quote & schedule
You receive a clear quote with a transparent price breakdown and schedule.
Foundation & shell
Groundwork, foundation, structure and roof. The extension is up.
Window frames & finishing
Window frames, insulation, services and the complete interior finishing.
Handover & guarantee
We walk through everything together and hand over neatly, with a guarantee on the work.
Our own team, no subcontractors
Your entire job handled by our own 20 to 30 craftsmen. Short lines, one point of contact.
One price up front, no surprises
You know where you stand from the outset. No unexpected extra costs afterwards.
1-year guarantee on the renovation
We stand behind our work and are only finished when you are satisfied.
Home extensions in Rotterdam and across the Randstad
Rotterdamse Bouwbedrijf is at home in Rotterdam, but we build extensions across the whole Randstad. From Rotterdam and Dordrecht to The Hague, Leiden and Amsterdam, and everywhere in between. Don't see your town listed? Do get in touch, we work throughout the region.
And also in, among others
We work with reliable A-brands, for a durable result with a manufacturer's warranty.
Questions about home extensions
Do I need a permit for an extension?
How long does a home extension take?
What is the difference between a rear extension and a stand-alone extension?
Can I keep living in the house during the build?
Where do you build extensions?
Ready for more space in your home?
Arrange a free, no-obligation consultation. We come to you, discuss the options and draw up a personal plan with a clear price.
What to watch out for with a home extension
An extension looks simple: a bit added to the house. In practice the result stands or falls on the foundation, the connection to the existing house and the flat roof.
Foundation and connection to the existing house
An extension gets its own foundation that ties into the existing one. Because new and old settle differently, we allow for differential settlement and finish the joint carefully. A sloppy connection is the number one cause of cracks between the extension and the house.
Breaking through to the inside
Usually you want the extension to open onto the kitchen or living room. That means removing a load-bearing wall and fitting a steel portal or beam, calculated by a structural engineer. This is where you decide how light and open the end result feels.
Flat roof, insulation and daylight
We insulate a flat roof well and give it a fall towards the drain, with an EPDM or bitumen covering. A rooflight or large glazed façade brings daylight deep inside. Watch for cold bridges at the connection, or condensation will form there.
Common mistakes
- Assuming permit-free building without checking the rules on plot coverage and depth.
- Insufficient insulation in the roof and floor, resulting in a cold, damp extension.
- No fall on the flat roof, so water pools and it starts to leak.
Would you rather go up instead of out? Then take a look at a roof extension. More space and a better energy label too? Combine it with window frames and insulation.