Mans floating home
This origami-inspired floating home is mostly made of timber and cork, radically simplifying its construction while creating simple yet elegant details. The project was intended to be distinctive from the established ‘shoebox designs’ along the picturesque canals in the city of Leiden. Summum Engineering provided the structural optimization and engineering of this unique design.
The architects, Studio RAP, designed the house as a series of smaller modules, rotated to face the lush nature on the opposite side of the canal, following an initial concept by the clients and interior designer Caspar Kienjet. Afterwards extra panels were added in between the modules and folded, creating intricate three-dimensional corrugated walls and roof. The exposed timber interior captures the natural light and creates a wonderful tranquil interior experience, while the exposed cork exterior blends in subtly with the atmosphere of the historical city.
The non-standard structure of this floating home was inspired by origami principles and folded roof structures. This resulted in less material for the same span and performance compared to a conventional flat roof. The load-bearing structure was completely made of cross laminated timber (CLT), with three layers for the 9 cm walls, and five layers for the 12 cm roof.
In close collaboration with the Studio RAP, the folds were designed and parametrically optimized resulting in a reduction over 2000 kg of timber, or 20%, compared to a traditional monopitch roof and straight walls, using a two-dimensional calculation. The model required a continuous update of the wind and snow loads, depending on the local angles of the facades, and inclinations of the individual roof plates. The resulting material savings were particularly useful to the client, as the floating home was subject to a maximum draft according to local regulations. This meant they could now allocate more weight to their actual use and furnishing of their home. In other words, more bang for their buck.
The clients intended their residence to be the most sustainable floating home in Leiden. As a result, the timber structure is entirely clad in cork – a low density cork insulation layer and a high density cork outer layer bonded by a cork mortar layer – creating walls that breathe with a healthy and comfortable interior climate as a result. Studio RAP ensured that all cork modules could be CNC cut, creating neat seams and bespoke window details. The house features intensive vegetation on its green roof, to enhance urban biodiversity, which was taken into account in the structural analysis. Sustainability was central in the overall digital workflow and guided most of the architects’ design decisions.
With a rising sea level and high urban population density, floating houses offer a resilient solution to the ongoing housing crisis. The concrete floater, produced by Hercules, was brought in by water. The CLT structure on top, supplied by KLH, came in a single truck and was erected by JM Concepten in the city center in one day, and completely fastened with screws the day after.
The project is also known as Mans, named after the grandfather of one the clients. The individual modules refer to farm plots, that Mans Middelweerd dealt with as mayor of Cothen, through land consolidation of the surrounding rural areas. In this way, the clients’ home pays homage to their ancestors.
Studio RAP | Wessel van Beerendonk, Olav Bouke van der Doorn
Summum Engineering | Diederik Veenendaal, Niels Hofstee
Location: Leiden, Netherlands
Size: 5.6 x 16.1m
Services: Structural engineering