Buildings contribute close to half of the energy use in the United States. Since energy is the number one contributor to global warming, an obvious way to mitigate climate change is to design low or no-energy use buildings.
To do so means going back to basics and looking carefully at how the design of a building is optimized to the particular features of a specific site to minimize the potential of extreme energy use.
Climate responsive architecture takes into consideration seasonality, the direction of the sun (sun path and solar position), natural shade provided by the surrounding topography, environmental factors (such as wind, rainfall, humidity) and climate data (temperature, historical weather patterns, etc.) to design comfortable and energy-efficient homes.
Determine the weather patterns, climate, soil types, wind speed and direction, heating degree days, and path of the sun. Look at the water flows, habitat, and geology of the site. Document each with a qualified team of professionals to understand the ramifications of building in that specific place. It is an approach which considers the best environmental sustainability practices.
Using an integrative design process, use a basic massing of the building layout to determine specifically on-site the most optimal location for the building to be situated. Factors to consider here are access to infrastructure, staying at least 100 feet clear of any watershed, not building within a floodplain and in a habitat with endangered species. Asking what trees and other existing geological features should be avoided or how water flows across the site can dictate the location of the building.
Its all about the sun, so, plan to place the structure based on the cardinal directions. The goal is to maximize the amount of sun that heats space in the winter (resulting in using less energy to mechanically heat), as well as decreasing the amount of sun that cooks the building in the summer (resulting in less energy to mechanically cool).
South facing facades should utilize a window area appropriate to its orientation, and glazing should utilize a double or triple-paned glass with a Low-E coating. It minimizes the amount of heat transmitted into space in the hottest months while keeping heat inside during the cooler winter months. For example, south-facing glass window wall will cook the occupants inside during the hot summer months if care is not taken to provide shade on the façade.
When designing the envelope of the building, factors such as insulation, vapor barriers, and air barriers will vary radically depending on whether the project is in the cold, snowy north, the hot and humid south or the arid desert.
Question the true needs of the program. Do you need that much space? Are there ways that spaces can become multi-functional? Do we need that many private offices if some staff can telecommute occasionally and share offices? Once your team is set on the minimization program, take a look at the size of your footprint. Is it possible to add extra stories to make the footprint smaller? That way, the building will have fewer excavation costs and more wall area that can benefit from the warming effects of the sun and an increase in natural daylighting.
Since warm air rises, a building can be cooled by designing for stack ventilation by drawing cooler air from openings low in the building, while carrying heat away through openings in the top of the space. The rate at which the air moves is a function of the vertical distance between the inlets and outlets, their size, and the difference in temperature over the height of the room. It could prevent occupants from experiences of sick building syndrome.
Most buildings in this day and age are designed to keep occupants fairly comfortable, at around 78 degrees Fahrenheit. However, with climate responsive design, reducing the amount of energy used to cool and heat the building can result in using natural systems, meaning the sun and the wind. With these, if building occupants are open to adding or removing layers during the seasons, it’s amazing how much energy can be saved. Adding a sweater in the winter or relaxing the company dress code to shorts in the summer can be enough to eliminate mechanical heating and cooling altogether, saving a bundle of money and the environment.
Energy modeling, lighting models, daylighting studies, computational fluid dynamics are all tools that designers can and should use to understand how the design best integrates with the local climate and micro-climate features specific to the site. Again, having the right team members with modeling expertise and software is the trick to keeping costs down while exploring the best options for the design.
If at first, you don’t succeed, try again! It will take the design team multiple passes of just these basic layouts in your pre-design or schematic design phase to hone in the lowest energy use possible, optimized for your specific site. However, it’s better to spend more time in the early phases of design to model the project, which is far less costly than making changes in the field or later on in the design process. Keep at the trials, and eventually, your building will be responding directly to the climate specific to the project site.