Skip navigation to main content. U.S. Department of Energy's Solar Decathlon | Powered by the Sun
Photo of 12 Puerto Rico team members in front of their unfinished house. Some team members sit on or stand inside a metal grid. The others sit on scaffolding.

The Puerto Rico team designed its entry for maximum connection to the outdoors and to serve as a model for energy-efficient homes in the Caribbean.

Illustration of the University of Puerto Rico Solar Decathlon 2009 house. It is  L-shaped with screened walls all around and a planted patio inside the L. Tilted solar electric panels cover the roof.

The Puerto Rico house's features include extensive screening that allows cross breezes but blocks overheating from the sun's rays. This rendering shows the strong connection of the two legs of the L-shaped house to the patio.

Construction Costs


Learn more about the
construction cost estimate


Construction Drawings (Zip 32 MB)
Project Manual (Zip 11.9 MB)

Neither the United States, nor the Department of Energy, nor the Alliance for Sustainable Energy LLC, nor any of their contractors, subcontractors, or their employees make any warranty, express or implied, or assume any legal liability or responsibility for the accuracy, completeness, or usefulness for any purpose of any technical resources or data attached or otherwise presented here as reference material.

Solar Decathlon 2009

Universidad de Puerto Rico

A Model for the Caribbean

The Puerto Rico team planned its house as a model energy-efficient dwelling for the Caribbean. The L-shaped 2009 entry clearly looks to the outside and responds to the opportunities and challenges of the Caribbean climate. The two legs of the L are connected by an outdoor patio, but only one leg is mechanically conditioned. The other is enclosed largely with special screens that allow occupants to look out and cooling breezes to pass through but block nearly 90% of the sun's rays. The conditioned leg uses those screens as well but also has sliding glass doors that can be closed off when conditions warrant.

The Team

The University of Puerto Rico is one of only two schools to enter all four Solar Decathlons. The 2009 University of Puerto Rico team is dominated by architecture students—some already graduated. Team member Zoé Galán Comas is one of those architecture specialists. "This project taught me not only how to design a home but also to plan a project and how very important that planning is," she says. For engineering advice, the team turned to the School of Architecture faculty members who specialize in technology, including electrical and mechanical systems, and to faculty members from other departments, who were very supportive throughout.

The House

The team bills the house as CASH—Caribbean Affordable Solar House. CASH is designed to maximize aesthetic and natural lighting and the cooling-breeze connection to the Caribbean outdoors. Redwood outside and teak inside—both reclaimed—add to the Caribbean ambience, as does the house's L-shape surrounding a central patio.

The Technology

Special screens that reject nearly 90% of the sun's rays while still allowing cross breezes and a view to the outside are the key technological feature of the Puerto Rico house, but other technologies include:

  • A 10.4-kW crystalline silicon photovoltaic system on the roof that generates electricity as well as vacuum-tube collectors for the solar water heating system
  • Radiant in-ceiling water pipes for heating and cooling that are designed to operate slightly cooler than the ambient temperature to avoid condensation
  • Tight-sealing, radiant-film-covered, triple-paned doors and windows made by a Puerto Rican manufacturer
  • An L-shaped design that readily divides into two separate pieces for easy shipping and provides for an easier assembly on the National Mall.

House Highlights

  • A model for energy-efficient homes in the Caribbean that is largely open to the outside
  • An L-shaped design that is closely connected to a central patio, with only one leg of the L mechanically conditioned
  • Special screens allow residents to look out and breezes to pass through but block unwanted solar heat—a passive energy feature that contributes to keeping the interior cool
  • Extensive use of reclaimed redwood and teak that adds to the Caribbean ambience