Daylighting: Natural Light in Architecture

Rothko Chapel, Houston

Architect Philip Johnson, followed by Barnstone and Aubry
Restoration by Jim McReynolds Architects

Lighting consultant Arup Lighting

Client Menil Foundation

The Rothko Chapel was built on a plot
adjacent to the Menil Collection in Houston,
Texas, to house a collection of paintings by
Mark Rothko, and opened in 1971. By the
1990s the chapel was in a bad state of repair.
The paintings themselves had deteriorated,
and a decision was made to take the
opportunity, whilst repairs were made to the
structure, to employ consultants to introduce
a new scheme for both daylighting and
artificial lighting to ensure the long term
future of the paintings.
The brief to the consultants, Arup Lighting,
was to propose alterations both to lengthen
the life of the paintings, and to improve the
quality of space for the visitors.
This Case Study is concerned with the
natural lighting, with the following brief:

1. To study the existing conditions regarding
   the amount of daylight and sunlight to
   which the paintings are exposed.
   2. To consider whether this exposure is
   excessive, in terms of the conservation of
   the work.
   3. To study the visual perception by the
   visitors, to assess whether the distribution
   of both daylight and sunlight is impairing
   the view of the works of art.
   The results of this enquiry would pinpoint
   any shortfalls in the existing daylighting
   design, and led to suggestions as to how they
   might be overcome. An extensive survey with
   both computer and physical models was
   conducted, and the results showed that the
   levels of sunlight penetration had been the
   cause of deterioration in the paintings, and
   that the daylight distribution caused
   unsatisfactory viewing conditions for the
   visitors. New proposals were essential.
   By a process of elimination a decision was
   made that the sunlight entering the space
   from the existing rooflight should be diffuse
   and scattered, rather than blocked, and that

this could be achieved by diffuse laminated

glass with a milky white opal PVB interlayer.

The incoming sunlight would no longer have

directionality, but an internal fixed shading

element would still be required to reduce the

quantity of natural light and to avoid the

bright skylight becoming a distraction to the

visitors, whilst at the same time assisting in

directing the light to improve the uniformity

to the light received by the paintings.

After a number of options were

investigated, this was achieved by a dropped

baffle, small enough to allow the full height of

the paintings to receive direct daylight, with

the addition of a central ‘oculus’ to provide

some daylight to the centre of the space.

The final result can be seen in the

accompanying photographs, and this has

proved to be well received by the public,

whilst obviating future deterioration in the

paintings.

144 Daylighting: Natural Light in Architecture

The exterior of the chapel after restoration in
2000

View of the new rooflight, 2000

Hickey-Robertson Jeff Shaw, Arup Lighting