Manu Prefab, New Building Methods
By Dagmar Reinhard
Over 15 years ago, Alexander Hruby, an engineer from Austria, began building houses in Costa Rica. The first thing he noticed was how diffcult it was for prospective house owners to understand their new environment. So, he created Manu Prefab, a full service, design and build company that specializes in modern tropical prefabricated homes. The focus was on how to embrace the natural landscape, environment, and sunsets while balancing sustainability and strength of construction materials.
Hruby has traveled all over Bali, Hong Kong, Japan, Malaysia, and China examining tropical architecture and materials. He has experimented on his own houses with wood, steel, Covintec®, and concrete blocks to find the perfect match between welcoming nature and protecting the structure and its inhabitants from the heat and humidity.
Recently, Alexander moved his attention away from wood frames to focus on galvanized steel frames in combination with Structural Insulated Panels (SIP), which are lightweight with an expanded polystyrene or a Styrofoam core bound between two sheets of Fiber Cement Panel. SIPs are lightweight, very strong, used for walls, ﬂoors, and roofing, manufactured under factory-controlled conditions, and can be designed to ft any type of building. Now, MANU Prefab can reduce costs and create better visual communication using the SIP panel format.
Prefabricating them before they arrive cuts down on labor onsite and overall construction costs. With SIPs, even the intricacies of electric wiring and plumbing can be preinstalled. Our calculations and tests in the field show that they are not only much stronger, lighter, and have more insulation, but the costs are also cheaper in general compared to conventional building methods used in Costa Rica; please see our blog posts for details.
SIP wall panels are lightweight, strong, and ﬂexible enough to withstand earthquakes; while, at the same time, their Styrofoam core creates unparalleled insulation. The air conditioning for a four-bedroom home can cost between $2,000 and $3,000 a month during the dry season.
SIPs, in combination with double-glazed windows, can reduce that cost substantially. The sun in Costa Rica is a natural resource, and yet, a tough challenge. Near the equator, the sun “bakes” the houses every day. It’s essential to have a good roof barrier. A 4-inch SIP roof panel has the highest insulation of any locally available roofing material. Since most of the heat transfer happens through the roof, insulating your roof is the single most important thing to do, especially if you don’t use air conditioning.
Manu Prefab strongly believes that the cost advantages, strength of the buildings, high insulation value, and time / cost-saving advantages of the prefabricated panels are very appealing. In combination with an optional galvanized steel frame, they can even install large window and door openings for that extra airﬂow to keep humidity and mold out. Each panel is cut and sized in their shop, and they immediately recycle its waste, which allows the construction site to stay clean.
Manu Prefab not only build wood houses using traditional Balinese techniques of interlocking joints,but now they also offer a new, modern, high-tech, green choice to build tropical homes.
InFo: ing. Mag. Alexander Hruby http://www.manuprefab.com