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DAYLIGHTI NG HOSPITAL PATIENT ROOMSA Summary o a Joint Research Study

What is a daylit patient room?

A daylit patient room uses light rom the sky or daytime

illumination, eectively reducing the need or electric light.

The amount o daylight that comes into a room depends

upon the area and location o the window and the amount

o the sky the window “sees.” The distribution o that

light is a unction o the window’s shape and location in

the window wall and the proportions o the room, room

reectivity, and obstructions within the space.

Does it cost anything to daylight a patient room?

I the hospital construction budget includes adequate

window area, shades, and electric lights, only a control to

turn o the lights, when daylight is available, must be added

(a short payback). The frst cost o the patient room can be

reduced i the design o the room’s structural, mechanical,

and daylight systems are considered together to lower the

oor-to-oor height, while increasing ceiling height and

improving daylighting.

Will daylighting save energy?

When daylighting is used to reduce ambient el

lighting energy savings during daylight hours c

as 87 percent.

Can it reduce the mechanical system size

Daylighting provides more illumination per wa

lighting and thereore less heat. When combin

task-ambient lighting strategy that only puts lig

needed, daylighting results in signifcantly less

room than typical electric lighting alternatives,

cooling load and the size and cost o the HVAC

Can daylighting improve patient well-bei

A patient room providing good outdoor views

can increase patient well-being: a psychologica

in reduced stress and anxiety, lower blood pres

post-operative recovery, reduced need or pain

and shorter hospital stays.1

INTERIORS

This is a brie summary o conclusions rom Daylighing Patient 

Rooms in Northwest Hospitals, a 2005 study jointly undertaken

by the Energy Studies in Buildings Laboratory, Department

of Architecture, University of Oregon (G.Z. Brown, Je

Kline, Gina Livingston, Brooks McDonald, Craword Smith,

Mark Wilkerson) and Zimmer Gunsul Frasca Architects LLP  

(Johanna Brickman, David Staczek).

The importance o surace reectivity

Daylighting depends on both the light received directly rom

the sky and light reected rom interior suraces. Patient

rooms with high internal reectivity will have more light at the

back o the room and more even light distribution. Minimum

reectivities should be: ceiling, 90 percent; walls, 70 percent;

oors, 40 percent; and urniture and equipment, 70 percent;

to allow daylight to reect o these suraces and penetrate

urther into the room.

Daylighting integration with electric lighting

Task-ambient electric lighting design strategies work well with

daylighting because room ambient light levels, lower than task

lighting requirements, are easy to meet with daylight. Ambient

daylight should be supplemented with task electric lighting to

increase lighting levels where specifc tasks are perormed.

To take advantage o available daylighting, electric lighting

should be designed and controlled either by dimming, or by

switching o completely. A light sensor and continuous or step

dimmer can maintain ambient illumination levels at a constant

value, based on the amount o daylight in the space.

As sky conditions change, automatic, dimmable, indirect

lighting luminaires make an unnoticeable transition rom

electric lighting to daylighting and back.

Patient control o daylighting

The ability to manipulate the environment, including bedside

control o lighting and window shades, contributes to a patient’s

psychological outlook, rate o healing, and quality o stay.3

Energy Studies in Buildings LaboratoryUniversity of Oregon

Funding or this document and or Daylighting Patient Rooms

in Northwest Hospitals was provided by the BetterBricks

program, the commercial buildings initiative o the Northwest

Energy Efciency Alliance. Supported by local electric utilities,

BetterBricks advocates or changes to energy-related business

practices in Northwest buildings.

1 Ulrich, R.S., “How Design Impacts Wellness,” Healthcare

Forum Journal, September–October 1992, vol. 35, pp. 20-25

2 Devlin, A.S. and Arrneill, A., Health Care Environments and

Patient Outcomes: A Review o the Literature,” Environment

and Behavior, September 2003, vol. 35, num. 5, pp. 665-694

3 Ulrich, p.23

Legacy Salmon Creek Hospital 

8/4/2019 Day Lighting Patient Rooms Brochure Final

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DESIGNING THE DAYLIT PATIENT ROOM

Positioning the toilet room

Outboard toilet rooms, placed along the exterior wall, greatly

reduce daylighting potential. For maximum daylighting beneft,

toilet rooms should be located between two adjacent patient

rooms, or placed inboard, adjacent to the interior corridor.

Room depth

The depth o the hospital room that

can be useully daylit is dependent on

the size and head height o the

daylight window. In our studies,

adequately daylit patient rooms, with

inboard or shared toilets, ranged rom

13 eet to 19 eet deep. Shallower

rooms are most desirable, because

they acilitate more even daylightdistribution to the back o the room.

Ceiling confguration and HVAC duct location

Higher ceilings allow higher windows and deeper daylight

penetration. An angled ceiling, sloping down rom the

bottom o the structure at the outboard wall to the nominal

ceiling height at the inboard wall (achieved by moving ducts

away rom the perimeter toward the corridor side o the room),

will allow a higher window head height.

Typical hospital patient rooms place a supply duct along the building

perimeter to oset drats rom glazing. High perormance glazing

allows the use o systems that can be located away rom the exterior

window, providing greater design exibility or the integration o ceilings

with daylight window head heights, within a given oor-to-oor height.

Glazing specifcations

Daylight windows should, ideally, have low u-valuesolar heat gain coefcients (SHGC), and high visib

transmission (VLT). Depending upon the climate an

aperture control capabilities, either the R-value or

may be relatively more important. Because they ar

or daylighting, view windows can have a lower vi

transmission and thereore, lower u-values and low

The best window wall confgurations

In plan, an angled window wall can have a dieren

than the rest o the building and potentially achiev

daylighting perormance. I the window wall is notc

designed with a corner window, the view window

dierent orientation than the daylight window.

Daylight and view w indow dierences

Daylight and view windows, in patient rooms, hav

and sometimes conicting requirements, and the

straightorward design resolution is to separate th

windows and their unctions.

The daylight window provides ambient light.

The view window, while also admitting light i

unctions primarily as the patient’s view to the out

stress, promoting relaxation, and even preventing

The daylight window should be located with its hehigh as possible in the wall and should extend the

the room.

The view window should be sized and placed to a

rom the patient’s bed and, to reduce glare, shoul

or o low visible light transmittance.

There are two approaches to sizing the daylight w

The frst optimizes the size o the window or both

and thermal perormance. The second sizes the w

maximum daylighting perormance and uses sha

light shelves and louvers to adjust its size, as neede

maintain the best thermal perormance, as conditio

Outboard Shared wall Inboard  

 Angled window wall Notched window wall  

Flat ceiling; typical   steel structure

Stepped ceiling; steel   structure; upturned beam

Sloped ceiling;concrete structure

A

B

C

B

A

A

D

E

F

F

D

E

15’ 0”12’ 6”

12’ 0”