ENCLAVE RESEARCH
02-04.2022
Pattern language of the Enclave : 10108702.wixsite.com/enclave/portfolio
Central space protected from the dynamics of the city traffic offers peace and quietness, the moment of a break.
SEE DESIGN
SITE ANALYSIS
Relying on the characteristics of the neighborhood and the building below itself, the rooftop serves a public function. It is not easily accessible from the street level and therefore is not a part of any pedestrian traffic artery. The isolation of this element of the environment, its' emptiness contrasting to the busy ground level, is what makes it an enclave.
RESEARCH
NOISE
POLLUTION
GENERAL
Excessive noise seriously harms human health and interferes with people’s daily activities at school, at work, at home and during leisure time. It can disturb sleep, cause cardiovascular and psychophysiological effects, reduce performance and provoke annoyance responses and changes in social behaviour. Traffic noise alone is harmful to the health of almost every third person in the WHO European Region. One in five Europeans is regularly exposed to sound levels at night that could significantly damage health. (WHO)
The WHO guidelines for community noise recommend less than 30 A-weighted decibels (dB(A)) in bedrooms during the night for a sleep of good quality and less than 35 dB(A) in classrooms to allow good teaching and learning conditions.
The WHO guidelines for night noise recommend less than 40 dB(A) of annual average (Lnight) outside of bedrooms to prevent adverse health effects from night noise.
How many people are affected?
According to a European Union (EU) publication:
- about 40% of the population in EU countries is exposed to road traffic noise at levels exceeding 55 db(A);
- 20% is exposed to levels exceeding 65 dB(A) during the daytime; and
- more than 30% is exposed to levels exceeding 55 dB(A) at night. (WHO)
Not all sound is considered noise pollution. The World Health Organization (WHO) defines noise above 65 decibels (dB) as noise pollution. To be precise, noise becomes harmful when it exceeds 75 decibels (dB) and is painful above 120 dB. As a consequence, it is recommended noise levels be kept below 65 dB during the day and indicates that restful sleep is impossible with nighttime ambient noise levels in excess of 30 dB. (IBERDROLA)
ROTTERDAM
The municipality of Rotterdam conducted a series of research analyses on the dynamics of the city, one of which being noise levels. Different maps highlighting the outcomes represent areas influenced by noise pollution in a wide range of categories.
Geluid in Nederland van wegverkeer (Lden)
Noise impact maps Rotterdam 2017
The main artery right next to the Bijenkorf entrance has annual average road traffic noise exposure of 72 dB (day, evening, night).
Another map represents an indication of the noise load on the facade of buildings as a result of road traffic, railways, industry, and aviation. This analysis only refers to "sound-sensitive" objects, which are buildings such as homes, schools and hospitals, and other noise-sensitive buildings. Department store de Bijenkorf had not been a subject of this study. However, data collected from facades of surrounding residential buildings indicates that an average in this area exceeds 65dB in category Lden (day, evening, night), and 30dB in category Lnight (from 11 pm to 7 am).
Noise in the urban environment can be combated in various ways to provide comfort for people. In indoor spaces acoustical energy spreads within the cube, reflecting from walls and scattering over the room. The focus lies on distributing the sound in a way, that situation requires, which can be amplifying volume from one source, minimizing resonance, or others.
In outdoor, urban landscape focus shifts to the receiver of surrounding, uncontrollable noise. There are different tactics for reducing acoustical energy through a barrier.
In outdoor, urban landscape focus shifts to the receiver of surrounding, uncontrollable noise. There are different tactics for reducing acoustical energy through a barrier.
NOISE CONTROL
REFLECTION
Reflection of sound contributes to creating echo and reservation, simultaneously not allowing any energy to pass through the barrier. Hard, flat, and dense materials allow the waves to bounce back from the approached surface at the same angle, returning slightly disturbed sound. Materials such as marble, granite, ceramic tile, smooth concrete, plaster, metal, and glass have lower sound absorption coefficient ratings, which means that more frequencies are getting reflected than absorbed.
This contributes to the cutting off of the path from a source to a receiver, allowing the sound to disperse in the same direction it came from.
ABSORPTION
On the other hand, acoustic energy can be captured in the material. Soft, uneven, and looser surfaces absorb the sounds, accumulating their' energy. Soundproofing panels used in acoustic studios capture the waves, allowing them to scatter inside, isolated from the receiver. Materials used for sound absorption have higher sound absorption coefficient ratings, which means more percentage of sound is being absorbed than reflected.
This solution not only guards the receiver against excessive noise but also prevents it from reflecting to the surroundings, decreasing potential noise poll.
.
In both reflection and absorption, another strategic layer can be added. Sound diffusion is a method used to spread reflected sounds evenly throughout space, diminishing its' vibrations by scattering one plot of waves into many directions. Toned noise is therefore affecting the receiver less directly than only by reflection.
One of the most efficient sound barriers in an urban environment is made out of greenery. Sound is absorbed by all parts of the plant such as leaves, branches, twigs, and wood. The rougher the bark the better it absorbs sound. Experts say the best species for this will have many branches and thick, fleshy leaves with thin petioles (leaf stem). These broadleaf species lose their effectiveness in the winter when deciduous.
Outdoor surfaces coated in plants can have much the same effect. It's why freeway sound walls are often planted with clinging vines such as Boston Ivy or creeping fig. On the ground plain, the most powerful tool is the lawn, due to its large area and excellent refraction ability. At the same time, plants create a lot of white noise, which is appealing to the human brain as a mask for undesirable noise. Additionally, greenery attracts birds and other wildlife that make their sounds further masking undesirable noise. (M. Gilmer)
