2011-12-11
IN THE RABBIT HUTCH
What human height and ceiling height tells us about our society
Summary
- Over the past 150 years, the U.S.lost world leadership in average height to the Netherlands and eight other countries, whose people grew taller faster.[1]
- Relative average height is considered a good way to compare overall physical health between societies[2] but not between individuals[3].
- There is little or no genetic component in the ultimate height of diverse human populations.[4]
- U.S.citizens are becoming shorter, relative to the people of other nations, because we provide lower quality environmental conditions, health care and nutrition than the ‘taller’ nations.[5]
- Over the past 150 years, as U.S.citizens grew taller, ceiling heights fell.
- We are allowing the construction of dark airless apartments, relative to the recent past, for reasons that are unrelated to the public good, namely profits.
- We can restore balance to the design of buildings by placing broad public health issues and individual experience at the center of every discussion on building design.
- Buildings that respond to the natural environment to provide natural light, direct fresh air and cross ventilation will be better to live in and interesting too.
- Viewing mundane issues through the public health lens can result in important insights and improvements to our quality of life and overall health.
- U.S.loss of leadership in human height and lower ceilings relative to height are symptoms of our failure to put people first, physically and psychologically.
Policy Recommendations[6]
- Place public health issues and resident experience, such as direct access to natural light and air, at the forefront of every discussion of residential building design.
- Require residential buildings perform as well as possible passively with no external or internal energy inputs, including site-generated solar and wind power.
- Change zoning codes to allow the construction of high ceilings without requiring developers to purchase additional land.[7]
- Change codes to remove disincentives to thick walls.
- Require volume and area be listed in for-sale or rent ads.
- Require passive heating and cooling performance be listed in for-sale or rent ads.
IN THE RABBIT HUTCH
What human height and ceiling height tells us about our society.
In a slow-motion version ofAliceinWonderland,U.S.citizens grew taller while ceiling heights shrank over the past century and a half. And, while a small but growing percentage of the U.S. population has to duck to pass through a standard 6’-8” high door, the really bad news is that the U.S. lost world leadership in average height to the Netherlands and eight other countries, whose people grew taller faster, over the same time frame. There is simply no good news in these facts. What do these trends in human height and ceiling height tell us about our society?
The average Dutch male has gone from 3-1/2” shorter to 1-1/2” taller than the average European-American in just one hundred and fifty years.[8] From 1850 to 2000 the Dutch increased in height from 5’-5” to 6’-0” while white European-American s went from 5’8-1/2” to -5’10-1/2”.[9] The statistics for Canadians and African-Americans are similar to those of white Americans.[10] As a result, Americans went from being the tallest people in the world to ninth and the Dutch went from eleventh to replace us as first. The Dutch increase in height is attributed to the Netherlands providing the best prenatal and early childhood health care and nutrition of any nation in the world.[11] The rate of height increase for Americans stalled after the 1950’s, a change that is attributed to declining health care, nutrition, and environmental conditions relative to places like the Netherlands and especially for pregnant mothers, infants and children.[12]
Scientists have recently determined that, with few exceptions, there is little or no genetic component in the ultimate height of diverse human populations.[13] This finding backed up by the experience of African-Americans whose height has increased from 5’-6-1/2” to 5’-10” from 1850 to 2000, U.S. immigrants in general[14], and populations in rapidly developing countries.[15] Thus Americans may be as tall as the Dutch a generation after we get our health care and nutrition to comparably high levels. And we may have more extra-tall people than the Dutch, since our diverse genetic pool will produce a broader range of outcomes–more very tall and more very short people–than a more uniform genetic pool.[16]
Relative height is considered indicative of a good general measure of overall physical health of a society[17] but not between individuals.[18] This correlation is an observation that many Americans would once have welcomed and may still embrace since we still perceive ourselves standing tall among the peoples of the world. We can see that Asians are getting taller. Who can see that Americans are getting taller at a slower rate than people in other industrialized economies? Who can see that while we are living longer we are improving our health care and environmental conditions at a slower rate than people in other industrialized economies?
TheU.S.population is generally ignorant of our loss of relative stature and the underlying connection to our overall health as a people. Yet surprisingly little political hay has been made of the loss ofU.S.leadership in human height, the loss of symbolic world leadership or of how meaningful this bad report card is for society. Much more has been made of the decline ofU.S.education relative to the rest of the world. But since the same environmental factors that support human height probably also support the development of intelligence and maturity required to succeed in school, the decline in human height and poor performance of our schools may even be related. One thing is certain; our failure to keep up with other industrialized countries in human height is, like education, another indicator of a broad societal decline, however relative and temporary, relative to our peer nations. Americans are becoming exceptional for the wrong reasons.
If our height tells us something about how we compare to other societies, our ceiling heights tell us something about what we think of ourselves. High ceilings have long been viewed favorably by our society and are still mentioned as a positive attribute of homes and apartments for sale today. Yet residential ceiling heights in the U.S.continue to fall relative to human height. To be accurate, the predominant residential ceiling height was standardized at about eight feet after WWII while human height has continued to increase. The zoning code, building codes, and industry standards all reinforce the institutionalization of eight foot ceiling heights and 6’-8” door heights for most dwellings at a time when millions Americans are over 6’-3” tall.[19]
It hasn’t always been this way. Most houses built middle class families before the standardization of eight-foot building materials had ceiling heights of nine to fourteen feet. From the mid-late 1800’s to the early 1900’s, the average American was an inch or two shorter than today yet their ceilings were typically far higher. The high airy ceilings, ventilated attics, wide porches and shade trees made many of these homes pleasant or tolerable on all but the hottest summer days. The houses were optimized for the summers because there were other ways of dealing with the winter cold. Up to the 1950’s, parts of a home were routinely closed off and unheated for the winter or for a portion of the day or week. This was possible because heaters were almost entirely point-source rather than central and distributed. Warm clothes, a comforter, warming stones, many children in one bed and a spot close to the fire were well-used options. Being close to the fire was a compromise; a good average temperature does not always equate to comfort when one side is too cold and the other blistering hot. As long as wood and coal were the fuels of choice the cook-stove was a good source of heat in the kitchen, the most-used room, from early morning to early evening. The kitchen was often warm all day and hot around mealtimes. Dining rooms were often heated only in the morning and evening. The parlor was left unheated except for company. Bedrooms typically had no heat whatsoever and bedroom windows were often cracked year-round to provide fresh air and eliminate condensation.
Ceiling height changed with technology. By the post-WWII boom, the eight foot ceiling was becoming a standard. Reasons included a desire for inexpensive housing, standardized building materials, increased cost of building materials, central heating, mechanical ventilation, thermostats, and changing patterns of dress and behavior. As a result, home built to post-war standards were almost universally less comfortable in summers than earlier homes had been. When air conditioning became common, cooling strategies such as cross-ventilation, open stairwells, high attics, wide screened porches and screened double-hung windows were often summarily dropped. From the mid-twentieth century on, more and more American homes were built in a way that made them intolerably hot without air conditioning.
High ceiling spaces have better air through greater volume and circulation, an advantage more apparent when heat is from smoky stoves burning wood or coal.[20] Low ceilings have reduced volume and less natural circulation from convection. High ceiling spaces are more easily lit using natural light from high windows. The move away from high ceilings was accompanied by increased use of artificial lighting, fixed windows, mechanical ventilation, air conditioning and a decreased emphasis on natural and cross ventilation, changes that also decreased the passive performance of the homes.
The paradox is that passively heated and cooled homes in temperate climates benefit from high ceilings and large volumes while mechanically conditioned homes are most energy efficient when building volumes are small. Different strategies result in different investments. For long-term sustainability, dependence on mechanical conditioning is the wrong strategy. We may want to consider some of yesterday’s strategies and especially rid ourselves of the idea that entire homes and apartments need to be uniformly heated 24/7.
As the demand for central heating, air conditioning and mechanical ventilation increased, giant industries formed around the sale and installation of these systems. Gradually, it was assumed that more and more buildings, residential and commercial, would have centralized mechanical systems. The high energy use of systems that conditioned large areas and volumes then drove the creation of conservation-oriented codes that focused on efficient mechanical systems. The current Washington State Air Quality Code does not even mention ‘window’.[21] The resulting environmental designs often inadvertently lowered the amount of natural light and air entering a building, limitations that have resulted in buildings with reduced air quality, that rot prematurely, and that may contribute to increased depression. The response has not been to revisit the big picture. Rather, the response has been more codes, more devices, and more complexity. The response has decidedly not been to mandate more direct access to natural light, fresh air and cross ventilation. Studies showing that depression is more likely in people with little exposure to natural light do not seem to have had an impact on building codes.[22]
Cities would be well served to review the performance of buildings in the passive state first, to make sure that they may be inhabited for some time with no input other than water and sewer connections. A primary focus on natural light, natural ventilation, passive heating and passive cooling will encourage better design and more healthy buildings. Such buildings are complex in their own way–but in ways that are sustainable, contribute to human health, and are responsive to local conditions. Investment should be aimed first toward making buildings that require no energy input whatsoever to be comfortable on as many days as possible. Designing to satisfy such meaningful conditions would result in organically complex buildings. The many unfortunate zoning provisions designed to make buildings ‘more interesting’ would not have been entertained if we required spaces to have relatively high ceilings with ample natural light and cross ventilation.
An additional argument for reviewing buildings in the passive state is the way we treat energy use as a society. We do not tell people they can not heat a 10,000 square foot house or an Olympic-sized swimming pool. We do, in practice, limit the natural light and fresh air available to small apartment or condominium dwellers by maintaining exceedingly minimal standards for light and air while aggressively tightening the mandates on energy efficiency. If all buildings were reviewed for success in the passive state, we might have many fewer people, rich or poor, using mechanical heating and cooling most days. The real question is whether we should review mechanical solutions at all. The market will eventually take care of energy waste. Codes and regulations that embrace and support mechanical heating and ventilation–even today’s efficient systems-may well leave a legacy of buildings uninhabitable without significant energy inputs. Cities should take the long view and imagine how we will work and live in buildings where little energy is available for heating, cooling and mechanical ventilation or such energy is too expensive.
The growing popularity of loft-style living in older buildings seems to be, in part, a result of individuals’ inclination to desire light and volume. It is not surprising that the rise of loft living almost exactly reflects the arrival of low ceiling heights. Most loft-style dwellings are created in existing commercial buildings where the ceiling height required already exists. Unfortunately, the economics of creating high ceilings of any kind in new spaces is made artificially expensive by the zoning code. The zoning code maintains a close and deliberate relationship between the height of the allowed building envelope and the number of eight-foot-high residential stories that can be constructed in the envelope. The relationship is so close that developers often build ground floors partly above or below grade simply to cram in an extra floor. To provide high ceilings, developers must eliminate one or more floor levels, drastically increasing the cost of each unit since more land must be purchased to build the same number of equal-area units.
To encourage high ceilings, we must separate the zoning height from the allowable number of eight-foot stories that can be crammed in. Designers need additional height to create sensible buildings – and it is unreasonable and to expect developers to give up building rights they have already paid for to provide this height. Rather, the zoning envelope should allow for a minimum of 12 feet per floor for both residential and commercial construction.[23] Developers will have no reason to build retail spaces above and below grade. The greater design height per floor will make for buildings that can be easily converted from commercial to residential uses and back again. Flexibility is a benefit for the city as well as for owners and designers.
There is no good reason for people to live or work in dark, stale, low-ceiling spaces. There is a reason that dark, low-ceilinged rooms are still commonly used in literature to describe spaces that symbolize poverty, danger and unhealthy conditions. Meanness in design reflects on our character. The reasons many Seattleites live in relatively dark airless spaces are entirely artificial and unrelated to the public good. This is not a dated problem – hundreds or thousands of studio apartments have been built in Seattleover that past two decades with one sliding glass door for both light and ventilation. Many of these studios are about fifteen feet wide and twenty-five to thirty feet deep. Astonishingly, codes recently began allowing enclosed bedrooms with no natural light or ventilation. Such rooms are known as sleeping closets and ridding the world of them was a driving force of zoning and fire codes that were developed over one hundred years ago. [24]
We can restore balance to the design of buildings by restoring consideration of basic public health issues to every discussion on building design. We can orient codes to make every building as successful as possible with no energy inputs (including site-generated energy inputs such as solar and wind power). Buildings built to maximize public health will have rooms with high ceiling rooms, great natural light and cross ventilation. They’ll be interesting too.
Xxxxx
[1] The statistics in this article are for male adults unless noted otherwise.
[2] pending
[3] pending
[4] The exceptional populations where genetics make a meaningful difference in height are small, such as Watusi and pygmi peoples.
[5] pending
[6] Recommendations to increase average human height in theU.S. is someone else’s book.
[7] My recommendation – allowable building height should allow twelve feet floor-to-floor heights.
[8] pending
[9] pending
[10] I have not found amalgamated statistics.
[11] pending
[12] Other environmental factors may also play a role – exercise, substance abuse, and environmental pollution are possible examples.
[13] There may be a genetic component in the height difference among individuals.
[14] Recent Maya immigrants fromGuatemala to theU.S. gained a record four inches in one generation.
[15] Japanese, Chinese and South Koreans have gained 1 to 1-1/2” every decade since the 1950’s.
[16] pending
[17] Although the relationships between the observations and the underlying forces are not well understood, the relationships exist. There is more controversy over relationships between height and socio-economics.
[18] There are positive and negative health aspects associated with being both short and tall.
[19] Door heights in middle class housing have also been standardized at a shorter height than those a century ago.
[20] Unfortunately, the elimination of polluting heat sources did not eliminate all air-born pollutants from the home since they were replaced by emissions from building materials and products brought into the home.
[21] Washington State Ventilation and Indoor Air Quality Code (2006 Edition) effectiveJuly 1, 2007.
[22] pending
[23] We should not decrease density by lowering the number of stories allowed – we should increase the height of the zoning envelope.
[24] See Bedrooms without Windows:
lightandair.wordpress.com 