How to Borrow Natural Light - An Architect's Strategy Guide

Summary

This video script delves into the concept of 'borrowed light' in architectural design, emphasizing its importance for sustainable buildings. It traces the history of daylighting back to the 1916 New York zoning resolution and showcases various strategies to maximize natural light, such as interior walls, translucent materials, and skylights. The script illustrates how these methods can transform spaces, making them brighter and more comfortable, and highlights their necessity in modern sustainable design.

Takeaways

• 🏢 The 1916 zoning resolution in New York City was a response to the Equitable Building's shadow, emphasizing the importance of daylight and air access.
• 🌞 Sustainable design practices have made the use of natural daylight a necessity, not a luxury, especially with the increasing focus on energy efficiency.
• 🏡 Borrowed light involves capturing light from the exterior of a home and directing it to interior spaces, which is crucial for rooms without direct exterior access.
• 📏 The sun provides a significant amount of light energy, with a clear day's illuminance being around 10,000 foot candles, despite reductions by clouds and glass.
• 🚿 Interior walls can be designed to collect and disperse light, using reflective surfaces to enhance light distribution in a space.
• 💡 Clear glass transmits the most light, and when positioned above eye level, it maintains privacy while allowing light to pass through.
• 🌫 Translucent materials are effective for borrowed light as they scatter light without direct visibility, providing comfort and reducing eye strain.
• 🚪 Full-height glass walls offer auditory privacy without visual obstruction, making them ideal for spaces with limited exterior window access.
• 📚 Stairways can act as conduits for light, especially when designed to capture and reflect light from above, illuminating lower levels of a home.
• 🪟 Interior windows are functional for light borrowing, allowing light in while maintaining privacy and being less expensive than exterior windows.
• 🌌 Skylights are an efficient means of borrowing light, especially on urban lots where they can be combined with light wells for maximum effect.

Q & A

What was the impact of the Equitable Building on New York City's architecture?

The Equitable Building, being the largest office building in the world at the time, cast a large shadow on its neighborhood. This led to the enactment of the city's 1916 zoning resolution, which aimed to preserve access to light and air at street level and influenced the design of many iconic towers in the city.

Why is the concept of borrowed light important in sustainable design practices?

Borrowed light involves capturing light from the exterior of a building and transporting it to spaces where it's needed. It's a necessity in sustainable design practices as it reduces the reliance on artificial lighting, thus conserving energy and enhancing the well-being of occupants.

How does the sun's illuminance compare to that of a full moon?

The illuminance from a full moon is roughly one foot candle, whereas on a cloudless day, the sun's illuminance is roughly 10,000 foot candles. This highlights the significant amount of light energy the sun provides, which is crucial for daylighting strategies.

What are some challenges in harnessing natural light for interior rooms?

Challenges include rooms without access to an exterior wall or spaces oriented in a way that restricts access to adequate daylight. Solutions involve using interior walls designed to collect and disperse light, clear glass for transmitting light, and translucent materials to scatter light.

How can interior walls help in borrowing light?

Interior walls can be designed to collect and disperse light rather than restrict it. They can gather indirect light from adjacent light-filled spaces and use the reflective nature of surfaces to diffuse light into other areas.

What role do clear glass and translucent materials play in borrowed light?

Clear glass transmits the greatest amount of light into adjacent spaces, while translucent materials reflect, absorb, and scatter light, making them effective for creating walls that borrow light. They help in preserving privacy while allowing the passage of daylight.

How can a stairway be used as a vehicle for borrowing light?

A stairway can be positioned to capture and reflect light from above, either by fully glazing it or using a skylight. This makes it an efficient way to illuminate lower levels that might otherwise be light-starved.

What are the benefits of using interior windows for borrowed light?

Interior windows bring in light from adjacent areas while preserving acoustical privacy. They are less expensive than exterior windows and can be operable to help with passive ventilation, adding functional and aesthetic value to a space.

How effective are skylights in borrowing light, especially on tight urban lots?

Skylights are highly effective for borrowing light, especially when used in conjunction with an interior atrium or light well and surrounded by reflective walls. They can transform tight spaces into well-lit areas by capturing light from above.

What is the purpose of a light tube in daylighting?

Light tubes channel light to where it's needed using highly reflective flexible tubing. They are particularly effective in private spaces or areas where a lot of glass isn't desirable, providing a simple technology to direct sunlight indoors.

How does the concept of borrowed light enhance the perceived dimensions of a room?

By using borrowed light, the perceived dimensions of a room can be naturally increased. This concept works well for spaces with floor area constraints, making them feel larger and more open.

Outlines

00:00

🏙️ The History and Importance of Daylighting

The paragraph discusses the historical significance of daylighting in architecture, starting with the Equitable Building in New York City in 1915. This building's large shadow led to the 1916 zoning resolution aimed at preserving light and air. The concept of 'borrowed light' is introduced as a strategy to capture exterior light and direct it into interior spaces. The paragraph emphasizes the necessity of natural daylight in sustainable building design and explains the measurement of light intensity using foot candles. It also highlights the challenges of bringing light into interior rooms and presents various solutions, such as using interior walls to disperse light, clear glass for transmitting light, and translucent materials to scatter light. The benefits of borrowed light, including increased perceived room size and improved comfort, are also discussed.

05:02

🌞 Innovative Solutions for Borrowing Light

This paragraph explores creative ways to incorporate borrowed light into architectural designs. It begins with the idea of using interior windows to connect spaces and bring in light, such as linking a bar to a powder room. Skylights are presented as an efficient means of borrowing light, especially in urban settings where space is limited. The paragraph also discusses the use of light wells and reflective walls to enhance the effectiveness of skylights. It mentions the importance of opening up interior spaces to distribute daylight and the use of higher sheen paint to help distribute light. The paragraph also touches on the impact of additions to existing structures on daylight and how to maintain it through strategic design. It concludes with a discussion on solar tubes, which are an effective way to channel light into private or glass-restricted spaces, and the aesthetic and functional benefits of using multiple solar tubes.

Keywords

💡Borrowed Light

Borrowed light refers to the architectural strategy of capturing light from one area and transporting it to another, often darker, space. It is a central theme of the video, emphasizing the importance of natural light in building design. The script mentions various methods of achieving borrowed light, such as using interior walls to disperse light, glass walls for transmitting light, and translucent materials to scatter light. This concept is crucial for sustainable design practices, as it reduces the reliance on artificial lighting and enhances the quality of indoor environments.

💡Equitable Building

The Equitable Building in New York City is mentioned as a historical example that led to the 1916 zoning resolution. This building was the largest office building at the time and cast a large shadow on its surroundings, prompting regulations to ensure access to light and air. The mention of the Equitable Building illustrates the historical significance of light in urban planning and the evolution of building design to accommodate natural light.

💡Zoning Resolution

The 1916 zoning resolution in New York City is highlighted as a response to the Equitable Building's impact on light and air access. This resolution imposed limitations on building envelopes to preserve daylight and fresh air at street level. The concept is tied to the video's theme by showing how regulations can shape architectural design to ensure the efficient use of natural light.

💡Daylighting Strategy

A daylighting strategy is a plan for the optimal use of natural light in a building. The video underscores the necessity of such strategies in sustainable design, where the smart use of daylight is essential. The script discusses how the sun provides a significant amount of light energy daily, and how this energy can be harnessed through various architectural solutions to illuminate interior spaces effectively.

💡Foot Candle

Foot candle is a unit of illuminance used to measure light intensity. The script uses the foot candle to compare the light from a full moon (approximately 1 foot candle) with the illuminance provided by the sun on a cloudless day (approximately 10,000 foot candles). Understanding foot candles helps to appreciate the amount of light that can be borrowed through architectural design.

💡Translucency

Translucency is the property of materials that allows light to pass through diffusely, rather than transparently. In the context of the video, translucent materials are used to scatter light, creating a softer and more comfortable lighting effect. The script mentions that glass can be made translucent through sandblasting, acid etching, or lamination, which helps in the borrowed light concept by preserving privacy while allowing light to pass.

💡Interior Walls

Interior walls play a crucial role in the borrowed light concept by acting as light collectors and dispersers. The script describes how walls can be designed to gather indirect light from adjacent spaces and reflect it into darker areas. This strategy is particularly useful for interior rooms without direct access to exterior walls, enhancing the overall lighting of a building.

💡Skylights

Skylights are roof openings that allow natural light to enter a building. The video discusses how skylights can be an efficient means of borrowing light, especially in urban settings with limited access to exterior window space. They can be used in conjunction with interior atriums or light wells to maximize light distribution, as illustrated in the script with examples of projects that utilize skylights to transform tight spaces.

💡Light Wells

A light well is a vertical shaft designed to channel daylight into the interior of a building. The script mentions light wells as part of the strategy to enhance daylight penetration, especially in lower levels of a building. They are often surrounded by reflective walls to increase efficiency and can be combined with skylights to bring light into areas with poor solar exposure.

💡Interior Windows

Interior windows are windows that are installed within the interior of a building to allow light to pass between rooms. The video highlights their use in borrowed light strategies, as they can bring light into spaces while maintaining privacy and acoustical separation. The script provides examples of interior windows being used to connect a bar and a powder room, adding an element of delight and interest to the architectural design.

💡Solar Tubes

Solar tubes, also known as light tubes, are devices that capture daylight and channel it into interior spaces through reflective tubing. The script describes how solar tubes can be an effective solution for spaces that require privacy or have limited glass options. They are particularly useful in directing light to areas that are difficult to reach with traditional windows, as shown in the video through the example of a grouping of solar tubes lighting a dark space.

Highlights

The history of light borrowing dates back to 1915 with the construction of the Equitable Building in New York City.

The 1916 zoning resolution in New York City aimed to preserve access to light and air at street level.

The concept of borrowed light involves capturing light from the exterior of a home and transporting it to interior spaces.

The sun provides an immense amount of light energy daily, with a full moon providing roughly one foot candle compared to the sun's 10,000 foot candles.

Interior rooms without access to exterior walls or with restricted daylight can be common problems in building design.

Interior walls designed to collect and disperse light can help solve the problem of light-deprived interior spaces.

Clear glass transmits the most light into adjacent spaces and can be used to maintain privacy while allowing light transmission.

Translucent materials are effective for borrowing light as they reflect, absorb, and scatter light without compromising daylight passage.

Translucency can be achieved through various methods such as sandblasting, acid etching, or using laminated glass.

Full-height glass walls can increase the perceived dimensions of rooms and are effective for borrowed light concepts.

Stairways can serve as natural conduits for illuminating lower levels in a home and are efficient for borrowing light.

Interior windows can bring in light while preserving acoustical privacy and are less expensive than exterior windows.

Skylights are an efficient means for borrowing light, especially in tight urban lots, and can be combined with interior atriums or light wells.

Light tubes are a simple technology that channels light to where it's needed using highly reflective tubing, effective in private spaces.

Painting surfaces with a higher sheen can help distribute light more effectively within interior spaces.

The concept of borrowed light can transform tight spaces into pleasant ones by utilizing light wells and skylights.

Solar tubes can be used to light up dark spaces effectively, with multiple tubes providing more intentional and functional lighting.

Transcripts

hi Eric here with 30x40 design Workshop

today I want to do a short course on how

to borrow light and it begins with a

little bit of a history lesson in 1915

the 38-story Equitable building in New

York City was the largest office

building in the world it contained 1.2

million square feet of office space and

consumed nearly every available square

foot of its diminutive lot it cast an

equally large Shadow on its neighborhood

in lower Manhattan its construction

inspired the enactment of the city's

1916 zoning resolu ution which was

designed to preserve access to light and

air at the street level the resolution

prescribed specific limitations for a

building's envelope its outer walls and

would go on to shape the stepped forms

that you see today on many of the iconic

Towers in the city it underscores the

importance that access to Daylight had

in shaping even the largest of cities

the individual buildings that make up

those cities and more broadly sensible

building design with an increasing focus

on sustainable design practices the

smart use of natural daylight in our

home homes is no longer a luxury it's

become a necessity at the heart of any

good daylighting strategy is a concept

of borrowed light the capture of light

falling on the exterior of a home and

transporting it to the spaces where it's

needed the sun delivers an incredible

amount of light energy to us each day to

get an idea of just how much it helps to

understand the standard by which we use

to measure light intensity the foot

candle light from a full moon is roughly

one foot candle while the Sun's

illuminance on a cloudless day is

roughly 10,000 foot candles of course

clouds and the filtering effects of

glass can reduce the actual amount of

light that reaches the Interiors of our

homes by some 50 to 90% but 1,000 to

5,000 foot candles is still an amazing

amount of light given that we only need

around 35t candles to comfortably read

by harnessing this light energy isn't as

simple as placing a window on an

exterior wall interior rooms without

access to an exterior wall or spaces

oriented in a way that restricts access

to adequate daylight are common problems

each with a unique solution here's a

look at some of those Solutions walls

interior walls built to collect and

disperse light rather than restrict it

are one solution the wall shown here

gathers indirect light from an adjacent

light filled bathroom and capitalizes on

the reflective nature of the Bath's wall

surfaces to diffuse it into the bedroom

clear glass will transmit the greatest

amount of light into adjacent spaces and

because the glass here is positioned

above eye level the bath remains private

and sound

isolated the White Walls of the same

bathroom act as the indirect light

source for the nearby bedroom bright

neutral colors work well for an indirect

borrowed lighting strategy good solar

exposure is Borrowed by the bedroom

simply via the glazed upper

wall because translucent materials

reflect absorb and scatter light they

make great walls for borrowing light the

degree of translucency will affect just

how much light is scattered the effect

is similar to obscuring direct sight but

Pres preserving the passage of daylight

diffused light is comfortable and limits

eye strain translucency can be achieved

in a variety of ways glass can be sand

blasted or acid etched it can also be

textured or laminated with laminated

glass a plastic interlayer lends a

translucent effect similar to that

created by sand blasting but without the

marking characteristics there are

applied films to consider as well full

height Glass Walls offer auditory but

not visual privacy when there's limited

access to exterior window space they're

an obvious

choice the perceived dimensions of our

rooms are naturally increased when we

use the borrowed like concept this means

it works particularly well for spaces

with floor area

constraints in this project the concept

of borrowed light has been applied to

the overall ordering system in place

there's a logic to the order of solid

and void and it offers plenty of light

to the bedroom space the pattern on the

glazed wall has been achieved with a

custom film The Design was created from

a sketch by the architect the vaulted

ceiling and clar story take advantage of

a reflected light from the entire volume

of

space stairs another option and an

efficient vehicle for borrowing light in

a home is the stairway it's a natural

conduit for Illuminating an often light

starved lower level if the stair can be

positioned to capture and reflect light

from above by either fully glazing it or

using a skylight it's even more

effective the combination of glass guard

and White Walls has made this stairway a

light source for the surrounding rooms a

solid wall used here would Chang the

space

dramatically interior windows whether

they're clear or frosted there are

plenty of functional incentives to

borrow light using interior windows the

ones here bring in light from the

adjacent living area while preserving

the nursery's acoustical

privacy interior windows aren't subject

to the same weathering and insulation

restrictions as exterior windows so

they're less expensive to buy and

install making them operable especially

in a stairwell where a natural

convective flow is greatest can help to

passively ventilate a space too

functional reasons aside interior

windows can offer unexpected Delight why

connect a bar in a powder room I don't

really have a good reason but I don't

really need one I love the idea that The

Powder Room will look different based on

what's on the top shelf and the time of

day in the bar too the differences that

The Powder Room renders to its

backsplash can be appreciated it's these

connections that make architecture

interesting linking spaces doesn't

always have to make sense functionally

or

otherwise skylights because the Sky Dome

above is a giant light source it's hard

to find a more efficient means for

borrowing light here than the skylight

on tight Urban lots a skylight can be

used in conjunction with an interior

atum or light well and be surrounded by

reflective walls to increase its

efficiency this project utilizes a light

well of sorts allowing the lower level

to borrow light from the upper skylights

the second floor hovers in the space

instead of being extended to the full

width of the Gable and the overall

effect is lighter and brighter the the

more we open up our interior spaces the

easier it becomes to bounce daylight

around from areas with good solar

exposure to areas with poor exposure

painting the surfaces with a higher

Sheen paint further helps distribute the

light this luminous shower is an example

of how a light well and Skylight can

transform a tight space into a pleasant

one additions to existing structures

often compromise the amount of daylight

the original building receives not here

though the Skylight ensures that the

existing home bar daylight at its

perimeter transoms similar in concept to

the ideas seen in the first images a

glass transom extends the dimension of a

space and introduces light to a room

without compromising its privacy light

tubes a simple technology solar tubes

Channel light to where it's needed using

highly reflective flexible tubing

they're especially effective in private

spaces or spaces where a lot of Glass

isn't

desirable although short tubes are used

in this project the concept is similar

six large tubes light this otherwise

dark space a bold and considered element

this choice of multiple solar tubes

rather than a single one not only feels

more intentional but as you can see it's

also exceptionally functional a grouping

of three is usually a good starting

point but the more the

better