Efficiency and Durability Best Practices in the Tropics
I’m informally advising a relative on building a house in her native country of Jamaica. The project is currently in the design phase, working with an architect on floor plans. The house will ultimately be four stories with three separate living spaces. The first three stories will be built now and the last story will be built at a future date, timeframe TBD.
My relative likes to keep temperatures in the low 70s year-round, which will obviously require air conditioning. In order to facilitate her temperature preferences – and an inexpensive, hassle-free retirement – I’m trying to help her minimize maintenance requirements, maximize the ability to control interior temperatures and humidity levels, and ideally facilitate future upgrades to make the house off-grid capable, as power outages in Jamaica are a frequent occurrence. Hurricane and earthquake resistance are also important, as is cost.
I still have some questions after reading these two articles:
-Are there any other good articles or resources worth looking into?
-My initial assumption was that we should limit south-facing windows, but both articles prioritize limiting east and west-facing windows; why is that? One article mentions that south-facing windows are “harder to shade,” but awnings aren’t very survivable for hurricanes, so they’re not a great option. Does the logic still stand?
-What are best practices for exterior foam insulation in termite-ridden climates?
Also, I’ve made some initial recommendations including the below. I would welcome any additions, corrections, extrapolations, etc.
-ICFs should be strongly considered, primarily because they will be much more air-tight than the much-more-common CMU construction. There is at least one ICF manufacturer on the island that has both blocks and an insulated roofing product.
-Air tightness around all penetrations and especially at the roofline (where most Jamaican houses have visible daylight coming in) is critical.
-The house should be simple and fairly rectangular to reduce surface area, reduce the number of potential ingress points for air and water, and to simplify roof geometry for PV and solar water heaters (the latter of which are very common in Jamaica).
-An asymmetric gable roof with an E-W ridge and as much uninterrupted south-facing roof face as possible is ideal – again, for PV and solar water heating.
-Roller shutters and/or exterior roller screens will be important to limit solar load (and, in the case of the shutters, increase disaster preparedness).
-Windows on the north and south side of the house to allow cross-breezes in accordance with prevailing N-S winds.
-While I don’t have any specific recommendations other than to use Borate-treated blocks for the first few courses of ICFs, great care should be taken to prevent termites from getting to the exterior foam.
-Because high-performance building is very rare in the country, training of the crew will be important.
-If the envelope is as tight as hoped, an ERV will be important.
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