In Objective 1.3, Video: “Environmental Constraints” approximately 8:30 states “To mitigate noise pollution on a project site, you could place buffering elements, such as vegetation or other landscape features.” This is not factually correct. Noise passes directly through vegetation of all kinds. Only solid sound barriers like masonry walls or significant berms placed very near to the noise source can to any measurable degree, protect a site from nearby noise.
@aidenjh While vegetation alone may not be the most effective sound barrier in reducing actual decibel levels, it can definitely alter the perception of noise (i.e. masking sounds with rustling leaves, creating a psychological separation). Simply put, vegetation can be used as a general environmental buffer and is a common “green” mitigation strategy for noise, glare, wind, etc. It’s definitely better than nothing and is aesthetically pleasing.
Solid sound barriers (i.e. masonry walls) are definitely more effective in reducing decibels, and this should be your answer choice on the exam if presented with a scenario about noise mitigation (considering it makes the most sense with all other factors). If vegetation is the only environmental constraint mitigation option listed, understand it as a simplification, not as a literal acoustic solution.
Kiara Galicinao, AIA, NCARB
Product Coordinator
Black Spectacles
Notwithstanding your point about psychological effects of greenery, this is one of those feedback situations where I’m sending this to BS to try to protect others from factually incorrect information. I’m often asking for an explanation of things I don’t understand, but in this case I am just pointing out an error in the curriculum that needs to go up the chain to someone who can go in and fix it at some point.
@aidenjh Thank you for the feedback. The reason why we include this in our study materials is because NCARB includes it in the ARE. I personally remember scenarios and questions in my study journey (and exams) that covered this concept. The use of vegetation as a sound buffer is indeed a valid piece of information worth understanding. Even though it is not the most effective solution, it is a general concept that is used on the ARE and in practice.
See the following NCARB-recommended resources:
- Architectural Graphic Standards 11th Edition
- Chapter 7 - Element G: Building Sitework - Site Improvements
- Site Planning and Design Handbook 2nd Edition
- Chapter 7 - Site Grading - Using Grade Effectively
- Chapter 10 - Vegetation in the Site Plan - Using Trees in the Landscape