Oosterpark Amsterdam

The starting point for this project was the owners’ desire to add an outdoor space to their apartment; situated in the two top floors of a house from 1885 in Oosterpark, Amsterdam. Since purchasing the apartment, the prospect of being able to use the house’s roof as a garden had been an important consideration. The garden should be as large as possible, and directly accessible from the inside. However, because the house was part of a protected townscape, the extension was not to be visible from the ground, especially from the street side. Therefore, the extension was designed as a room in the middle of the roof, with a garden terrace on either side. The façade of the room faces the two terraces, and consists of glass doors that can be folded away; enabling the room to remain continuous from inside to outside. On the sides towards the neighbours, the new interior is bordered by two closed elements that house the stairs and large built-in cupboards. The boiler, washing machine, and dryer were also moved here from the bathroom below.

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Prefab elements arriving on-site

The weight of the extension was transferred by the means of steel beams on the building’s two firewalls. Not uncommon for a building from this period, these walls were tapered on the upper floor, so an additional steel structure had to be installed to carry the load. The only other perforation in the roof was for the stair opening. The new staircase was modelled after the existing staircase in the house for a seamless transition throughout. Above the stairs, there is a skylight from which no details are visible from the inside, giving the user an impression of being outside. The interior of the entire extension is painted white to reflect the light. 

The outside of the building and the planters are clad with red cedar wood; the railings are of galvanised steel. To save on weight, the garden is laid out in planters on a layer of substrate and foam. The planters contain a watering system, and lower-half drawers for garden tools. Strict sight-lines meant that the front of the roof could not be used, so flower meadow was planted there instead, which saw the trees of Oosterpark being used as a backdrop.