SLIM VOLUMES.

With ingenious interlocking spaces the architects have brought light and air into two narrow waterfront strips.

As everyone knows, the Netherlands is one of the most densely populated countries in the world. At the same time, it has a healthy economy and there is a demand for moderately priced housing. The pressure on land is very great, as is the need to reinvent ways of using it. The situation, allied with the civilized tolerance and admiration for invention so characteristic of the Dutch, has allowed young architects to prove themselves. The result is that the Netherlands is at present one of the most architecturally vital of countries.

MVRDV is one of several youthful practices that appear to see constraint as the engine of invention. The practice's Mondrianesque talent for manipulating and balancing plane, form and volume in pushmi-pullyu fashion, has been applied to the design of two houses in the Amsterdam district of Borneo-Sporenburg. Conforming to an urban plan by West 8, this is the most compact new housing district in the Netherlands, and constraints on space, by most standards, are extreme. But then the Dutch have traditionally turned living in narrow strips into a virtue.

Both houses look on to water on one side and the street on the other. Plot 12 is 5m wide and I 6m deep. Since there had to be space for parking a car, the architects established a narrow alleyway and designed the thinnest house imaginable beside it -- only 2.5m wide, although bulging out in places into and over the alley. Within this strip is an extraordinarily ingenious composition of interlocking volumes.

Glass is an important component of the design. A full-height glass wall lines the alleyway, letting the maximum amount of daylight into the interior and allowing space to flow outside. Each of the two ends are enclosed. The house descends from the street to the water, the change in level allowing the sloping roof of an alley shed to become a parking space. Above the alley, two enclosed volumes hang off the glass face at different levels, extending interior space and imparting a medieval flavour to the passageway. One extension provides a guest room and roof terrace, the other provides extra width for first and second-floor studios.

According to West 8's plan, Plot 18 is designated a garden plot, 4.2m wide and the same 16m deep, with a 4m-deep garden giving on to the water. In principle, only three floors were possible within the 9.5m-high envelope, given the requirement for a double-height room at ground-floor level. In spite of this, MVRDV's scheme manages to provide four floors. By sliding out the third floor over the water at the back and enclosing it to form the main bedroom and bathroom, the architects freed up the house's plan and section. Having installed another closed volume, a garage-cum-store, off the street, they created a series of interconnecting spaces on four levels linked by stairs through the centre of the building.

Differing in height and their degree of privacy, the various rooms give on to the water in different ways. On the ground floor, the dining room flows through a glass wall on to a double-height verandah; above is the glass bay of the bedroom, and above again, a roof garden off the attic studio.