Masstricht, Netherlands

“I’m happy with my wife,” says Dutch architect Wiel Arets, “because we are comfortable together and yet she still challenges me. Every day we discover something different about each other. This is how architecture should be.”

Arets has tried to achieve that goal with his design for a 2,251-square-foot glass house in a hilly suburb of Maastricht, the Netherlands, for dancer Jo Willems and actor Jan van Opstal, both of whom are also landscape architects.

The two-story house opens out to views and light by the careful placement of thick, UV-resistant, double-paned transparent glass walls alternating with translucent and opaque glazing. The skin encloses irregularly shaped volumes where a poured-in-place concrete structure of columns and slabs allows spaces to have an open plan. Since Arets placed the columns to be as unobtrusive as possible, the central staircase, made of Corian-covered plywood and suspended from the second floor, provides a dramatic sculptural element.

(A handrail is inserted along one side.) At the base of the stair, three Corian-sheathed pieces of furniture act as stepping stones down as well as functioning as seats or tables.

There are only two enclosed rooms in the house — the bathrooms, which have been fit-out with fixtures from a line Arets designed for Alessi. The rest of the house can be partitioned into different spaces by curtains made of parachute material. “The clients are interested in movement,” says Arets, “and they wanted a space that could be a kind of stage for living — a space that would change to suit whatever activity they were involved in.” Even the beds are on casters, the better to rearrange space at will.

The architect naturally had to face the question of energy use. “Hardly any air-conditioning is needed,” he says, “because like a stone church, the concrete columns, floors, and ceilings absorb the heat during the day, keeping the house cool in the summer.”

Nevertheless, Arets inserted a radiant heating and cooling system in the concrete floor and ceiling slabs for very cold or hot days. During the summer the system is supplemented by cooling tubes integrated into plasterboard walls installed behind the opaque, gray glass panels.

Willems and van Opstal have created a lush formal garden behind the house, which they open up to the public several times a year. Being able to observe the landscape in different seasons is paramount: “We are gardeners, and since every season changes so dramatically, we really live with those variations in this house,” says van Opstal. Arets agrees with both clients’ attitude, adding, “People rethink their ambitions each day. Why not live in a house that can adjust to these different moods?”


Jan van Opstal, Jo Willems

Wiel Arets Architects
D'Artagnanlaan 29
6213 CH Maastricht
the Netherlands
Phone: +31(0)43-351-2200
Fax: +31(0)20-577-6008

Personnel in architect's firm who should receive special credit:
Wiel Arets, Satoru Umehara, Harold Hermans, Daniel Meier, Dennis Villanueva

Interior designer
Wiel Arets Architects

Ingenieursbureau Palte (

Wetering Raadgevende Ingenieurs (

Wetering Raadgevende Ingenieurs (

Wetering Raadgevende Ingenieurs (

General contractor
Wim Knols Bouw bv (

Jan Bitter ( (

Christian Richters (

Wiel Arets Architects

CAD system, project management, or other software used:



Structural system
Ingenieursbureau A. Palte bv (

Bitumen roof with basalt split

Schüco FW50+ (

Saint Gobain: HR++, K=1.5, 8-15-66.2 Ipasol 60/31 (transparent glass)

Saint Gobain: HR++, K=1.5, 8-15-66.2 Ipasol 60/31 + white foil (translucent glass)

Saint Gobain: SGG Emalit 8mm (grey emalit glass)

Schüco Royal S120+ sliding doors (

Wood doors:
Custom made

Sliding doors:
Schüco Royal S120+ sliding doors (

D-line (

SOSS invisible hinges (

Dorma BTS 80 (

Exit devices:
Custom made, design by Wiel arets Architects, material Kerrock (

Interior finishes
Special surfacing:
Kerrock surfacing on custom made kitchen and staircase, designed by Wiel Arets Architects (

Power floated concrete floors, finishing impregnation Faceal Oleo HD (

Interior ambient lighting:
Halogen Wall lights, Alessi DOT by Wiel Arets (

Task lighting:
Kitchen pendant light, Hato Uni-q HiLo (

Jung LS aluminum, KNX ( 

Freestanding bath, Alessi Il Bagno DOT by Wiel Arets (

Double washbasin, Alessi Il Bagno DOT by Wiel Arets (

Water fountain, Alessi Il Bagno DOT by Wiel Arets (

Toilet, Alessi Il Bagno DOT by Wiel Arets (

Shower Cabin & Fixtures, Alessi Il Bagno DOT by Wiel Arets (

Faucets, Alessi Il Bagno DOT by Wiel Arets (

Add any additional building components or special equipmentthat made a significant contribution to this project: Uniwarm heating and cooling system (