A former factory space in Utrecht-Lombok was converted into a loft apartment with a mezzanine floor. We handled the design and structural calculation. The additional floor level on steel beams increases the living area by 22 m² without requiring a permit.
Illustrative blueprint view · tall space before, mezzanine floor sketch, 3D impression and the delivered result.
The owners of a loft apartment in a former factory in Utrecht-Lombok had almost 5 metres of clear height but little usable floor area. A mezzanine floor seemed the solution. The challenge lay in the structure: the existing concrete external walls could not be pierced for beam support, and the floor had to comply with the fire safety requirements of the Building Decree without a permit being required.
We designed a self-supporting steel structure on four slender columns standing on the existing concrete floor. The structural engineer calculated the HEA beams for deflection and fire rating. Because the columns are on the inside and are not anchored to the external wall, no building permit was required. The design took into account the clear headroom on both levels and the existing window positions.
The mezzanine floor adds 22 m² of extra floor area on the sleeping level, with an open balustrade that preserves the loft feel. The structure was assembled in 3 days. The openness of the space has been retained: the ground floor benefits from double height in the central living area. No permit required, no aesthetic review.
Key project details
What we delivered
Whether you are in Utrecht, the Randstad or elsewhere in the Netherlands: we handle design and structural calculations from A to Z. Since 2016, 800+ projects. A no-obligation quote within 1 business day.