A few years ago I attended a conference in Puerto Rico on climate change mitigation for buildings, and I remember thinking how ironic it was to be discussing this subject in a building with floor-to-ceiling, south-east facing glass windows and the ACs on full blast to counteract the heat from the mid-morning sun!
This is an example of a building that was NOT designed to harness the latent potential of its site. When we design buildings for the tropical climate one of our biggest priorities is achieving thermal comfort without the use of air-conditioning. Especially in countries in the Caribbean where the electricity costs are so high, and a natural disaster may leave you with no power for days or weeks. We incorporate passive design elements like brise-soleil, walls with air gaps, light shelves, deep overhangs, roof, and wall insulation, and even shade from trees to diffuse the light and reduce heat gain. These decisions impact the floor layout, and how the building looks and performs. Before we draw a single line, we embark on detailed site analysis. It is important to decide on the passive cooling, natural lighting, water harvesting, and sewage disposal strategies early in the design process so that we can minimize the need and dependency on mechanical systems.
We do appreciate that site analysis is not the expected first step, and many of our Clients are not aware of the benefits of approaching the design with these priorities in mind. Usually, architects/designers tend to focus first on what the building will look like, then work on to how the building responds to the site, and finally address the mechanical systems required to fulfill the building's lighting, cooling, water supply, and disposal. We turn that process on its head, and though the difference in approach may seem subtle, they have a substantial impact on how the building looks and works.
As the awareness of climate change, and the impact of our choices on the environment grows, more of our Clients appreciate getting the right balance between design priorities that promote comfortable living while incorporating green initiatives and climate mitigation measures. Striking the right balance is not easy and often these priorities lead to conflicts such as:
Client preference for walls with large expanses of glass so they can maximize views. Sea-front properties in Belize tend to primarily face east which exposes them to the morning sun. To counter the heat gain from this, we incorporate shading strategies. Oftentimes, shading devices can double as hurricane protection, and may even be employed to deter burglars.
Deep eaves and overhangs are great for passive cooling and diverting the rainwater away from the walls and foundation. However, high winds and a drop in pressure during strong storms and hurricanes may contribute to the roof being pulled up from the walls. We make sure to incorporate additional roof reinforcement to strengthen the roof’s connection to the walls.
Square or hexagonal-shaped buildings with hip roofs are the ideal configurations to withstand hurricane wind loads. However, these shapes are not ideal for maximizing natural ventilation and views. They also tend to increase the number of internal walls leading to costly circulation spaces. We strive to find the optimal balance between the right shape, and the right roof.
All of these issues have solutions and Clients who are aware of the complexities involved in adapting to climate change & incorporating green design strategies tend to appreciate this, and make more informed choices. The best outcomes are achieved when the objectives are clear, the relevant issues identified early and the appropriate solutions developed.