What is low embodied energy?
Mix of materials to meet broadest market
Designing for Efficiency
Efficiency of labor
Foundation and floor
PEX water piping
Bio-digester sewer system
Bamboo posts and attachment
Roof sections, overhangs, material costs
Zinc, the roofing of choice
These affordable, sustainable, energy efficient, houses sprung from the bamboo treatment business we started as a way to grow a market for sales of bamboo locally. These houses are designed to be affordable, efficient, and ecologically sustainable.
The many design aspects of these houses discussed on this page.
There is a need for low and moderate income housing thru-out the world today. Homes that embrace energy efficiency and are still aesthetic, comfortable homes that will last for generations.
The shell of a house is about 50% of the final cost. There is limited room to reduce the cost of construction while still using quality materials, maintain beauty and efficiency. Therefore increasing construction efficiency of material use and labor is the most effective means of reducing costs.
Sustainable, ecological, energy efficient design is at the forefront of our designs.
Houses need to be energy efficient, with reduced maintenance, and will last for generations, if they are to be considered environmentally or economically sustainable in the long run. House design always needs to consider location variables such as weather, topography, and risks like earthquakes, hurricanes, etc. There are no hurricanes in Panama, but there is lots of rain and humidity plus strong winds in the dry season. Our houses take all of these into consideration.
Our Octagon 1450 sq ft and 1800 sq ft houses are designed using research that shows present trends in the sizes and styles of houses consumers are buying in North America. This represents our largest market. Trends are moving towards smaller homes in general and as the baby boomer generation retires. Open floor plans with great rooms are still, and should remain in vogue. The Boquete market shows that homes above $200,000 are having a harder time selling and there is a shortage of quality homes below $200,000. This looks like the future of the real estate market and finding quality in this price range is a challenge in today’s market.
We have chosen to use the very highest quality materials in the homes we are constructing at the Lemon Grove Estates project in Boquete. As mentioned above, only high quality building materials are used for the shell of the house, including treated bamboo and pine T&G, plycem walls with steel studs, Styrofoam insulation, PEX plumbing and romex wiring. But we have also use porcelain tiles, custom cabinets and doors, granite countertops.
We have been able to provide this quality while keeping the home prices below $200,000 by reducing the labor costs required to make these homes.
Having an appropriate energy efficient building envelope will provide comfort, quiet and if air conditioned, significant electrical savings for the life of the house. Designing structures that incorporate natural lighting, with appropriate insulation and ventilation are key aspects. Why would you spend 5 times as much for 90% LESS?
Most people don’t think about the comfort of the home from an energy or noise standpoint when they are buying a home. A house that is too hot when it’s sunny, and too noisy when it is raining, are long term comfort and livability factors. Roof and wall insulation requirements vary in R value depending on the buildings energy usage. The side benefit, but very important benefit, of thicker, higher R value insulation is sound reduction during heavy rains. These houses are designed to be energy efficient over their entire lifetimes and quiet.
If you are air conditioning these houses, the savings show up in your utility bills every month. In the lowland tropics of Panama, with some of the highest electric rates in the world, this savings is significant. In low elevation areas of high heat where AC will be used, it is possible to install 4” of Styrofoam insulation on the roof instead of the 2” we install in the cooler mountain areas.
The large overhangs we install reduce sun and weather exposure on walls. Also Plycem is about ½” thick vs 5-6” for a block wall with stucco. Its ability to retain heat and transmit heat into the building is 1/10th or less than block. The wall has an air space that has very low capacity to hold or transmit heat. This significantly reduces interior heating due to late afternoon or early morning sun exposure to walls. Where appropriate additional insulation can be added.
In Boquete there is no need to insulate walls. The plycem is de-coupled by an air space so morning or evening sun will not conduct into the house. Compared to block houses, where the suns energy moves thru the wall at about 1” per hour. After sun exposure, the house starts heating up about 4 hours later, and continues for another 5-6 hours depending on the thickness of the walls and stucco. In hot areas, walls, or even just a room or two, can be insulated if the building is to be air conditioned.
Compare this to the typical construction here. Block houses have walls that absorb and retain heat from direct sun exposure, and, the heat of the day. Bubble wrap roll insulation, used on roofs, has an R value of 1, versus, 2” of Styrofoam insulation used in our homes at an r value of 10. We install 10 times the R value (and noise reduction) of roll foam or bubble wrap insulation.
The roll insulation is five times more expensive than the Styrofoam per R value delivered. Natural indirect lighting is provided by the cupola. These cupolas add a lot to the cost of the house, but everyone loves the aesthetic ceiling structure and the natural light they provide. This is a gentle indirect light. We don’t use skylights, even though they are cheaper. Skylights provide direct lighting but also a lot of heat from solar gain. Natural, indirect light from the cupola also equates to electrical savings.
It is all the energy that goes into a product or material. From extracting the raw materials from the environment, transportation, manufacturing, warehousing and final transportation.
It is the fossil fuels that were required to make this product which reflects the CO2 that was placed into the atmosphere to make and transport it. Labor is also energy intensive as well. Transportation and the costs of keeping a family while a product is being manufactured. Low embodied energy products will take less energy to produce, and transport.
We are working on systems using materials that are locally available and increase the environmental sustainability of these houses.
Bamboo is 7-12 times more renewable, than tree farms, and stronger than steel for its weight. Bamboo sequesters many times more CO2, and grows locally. The bamboo species we use is one of the top ten construction bamboos in the world. The labor savings represents a lower energy input.
Concrete and steel are very high embodied energy product and due to the lightness of the house, we can use a lighter foundation and less of these high embodied energy materials.
Compare this to standard construction that uses almost all very high embodied energy materials, and a significant increase in transportation and labor costs to install them. These houses are also very energy efficient, see Energy efficiency above.
Rather than using too much of any building material, like all gypsum walls and ceilings, or all wood log cabins, we chose to balance the aesthetics with a mix of materials.
We could use much more bamboo in the building of these houses, making them more sustainable. Bamboo could be used in place of the tongue and grove for less, it could also be used in the walls, but we have chosen a mixtures of materials and styles to balance the design aesthetically and environmentally. These houses look like typical open beam ceiling mountain homes except bamboo is used in place of wood. Compared to typical construction here with either sheetrock or hung office style ceilings and stucco walls. We think this increases the marketability and resale value of these homes.
The width of the walls are in 2 ft increments to eliminate waste of plycem siding and gypsum. The walls are designed to efficiently use the steel stud material.
Walls are designed to utilize 20 ft lengths of steel studs with very little waste. A house typically has about 3-4 five gallon buckets of steel scrap that goes to be recycled. Walls are premanufactured on site with cross bracing in place ready for installation. These walls are stacked until ready to install. The posts are bolted to the floor and the walls are screwed in. Treated plywood shims are used as needed. Bamboo beams are placed on top, bolted to the posts, and screwed into the walls. Walls are concrete nail gunned to the floor. The walls use steel studs that are structural, so either the bamboo posts or the walls are capable of supporting the structure independently.
The walls are designed in 2 ft wide increments to accommodate the plycem and gypsum without a lot of waste. This means less cuts, less joints to tape as well.
The labor to install these materials is also reduced.
This is the key to making consistent, quality, affordable houses.
These houses are designed to use a crew that is between half and a third the size of standard construction and complete houses in ½ to 1/3rd the time. This results in a significant reduction in labor. Much of these savings are used in the higher cost and quality materials like treated bamboo, pine ceilings, custom cabinets, etc. Part of the savings are used to reduce the cost to the consumer. Compared to standard construction, we have a higher percentage of material costs in our houses.
Reduced waste means faster installation. PEX piping reduces labor. Romex wiring reduces labor. Less cutting of steel studs, sheets of plycem, sheetrock means less labor. This is why these materials are used in high wage countries like the US and Canada. Use of forms, pre-welded connectors, a book of processes, measurements, procedures to be followed, all reduces labor. Repetition reduces labor.
All these labor reducing processes, with the addition of repetition, use of forms, lists of materials, not only reduces construction time, but also improves and maintains construction quality and consistency.
These houses are by design, made to be affordable, consistent quality and give the client confidence in the process. Time is money and the longer it takes to complete a house, the more loss in loan interest, or rental of a place to live while the client waits.
Building materials are the bulk of a home. We offer high quality materials, and we find ways to use and install them more efficiently.
Building materials are expensive and the materials we use are some of the more expensive you can use like, walls from steel stud, plycem with a commercial acrylic stucco finish. Sheetrock gives a much faster, better finish than, heavy, labor intensive concrete block and stucco.
Treated Bamboo, while less expensive, stronger, and far more beautiful than a steel carriolas, or treated wood beam and posts, is still an expensive building product. Tongue and Groove treated Canadian pine is a very expensive but make a very beautiful ceiling, that we extend out to the eves for the aesthetics and to reduce sound. 2” of Styrofoam insulation costs far more than a roll of ¼” roll bubble or foam insulation, but is 5 times less expensive pre R value.
Our houses are specifically designed to make very efficient use of these expensive materials so there is very little waste, and reduction in installation costs. Compared to other construction systems, the percentage spent on labor is much less. Your final product contains a much higher percentage of materials, and higher quality materials, compared to other construction systems.
These materials have other beneficial qualities when compared to other houses. The bamboo is treated and is stronger, lighter and more beautiful than carriolas. You would never expose a carriola ceiling. If you did you would have to use 2 carriolas welded together and it would cost almost double.
Treated tongue and groove pine is not only far more beautiful than sheetrock or the “office style” panels, it offers additional insulation against sound and heat. Compared to the suspended ceilings that look like an office building, they do not seal well, if there is a strong wind, then they can rattle and even blow off. It is impossible to clean above them and it is a breeding ground for insects. Sheetrock on ceilings tends to sag over time and show its seams and connection screws.
Steel walls are not only recyclable, they are rot and termite proof. They are also structural. The bamboo can hold up the house without the walls, and, the walls are strong enough to hold up the house without the bamboo.
Plycem and gypsum are much faster to install than stucco, this is why they are the preferred materials in the developed world where labor rates are 4-8 times higher! These also provide a flat, smooth surface. Compared to stucco that is much more labor intensive and very difficult and costly to obtain a flat smooth surface.
Insulation: This design allows for the installation of Styrofoam insulation from 2-4” thick and is unique. Compared to the standard 1/4” thick roll of foam or bubble wrap, the cost per R Value is significantly less, even though the overall cost is significantly higher. This makes this design very energy efficient and QUIET. Both important factors in a tropical climate with heavy rains.
This is a critical part of any home. It must support the weight of a home without settling or cracking and survive an earthquake. The heavier the home and the higher the home the greater the stresses are on the foundation.
In liquefaction areas, like bay fill over mud or sandy beaches the use of heavy, concrete wall homes on foundations unable to support them is an issue. In these areas floating foundations are utilized. They are built extra strong with reinforced floors so that they can support the building (float) without relying on the soil. The use of light structures is also critical in these areas. Heavy homes make floating foundations un-economical, but our light house design is perfect for these types of foundations. These lightweight bamboo structures can also be built on framed floors, cantilevered over hills, something that is a cost multiplier in concrete block buildings. The floor plan is also evenly divisible by 4X8 sheets of Plycem so that waste is reduced if floor framing is used.
The floor is a structurally integral part of the foundation, unlike a standard foundation with un-reinforced floor poured afterwards. These buildings weigh about ¼ of a block house and ½ of a stucco structural skin house (M-2). This means that we can use a much lighter foundation to support them.
Standard foundations have 3ftX3ft pads under each post, with a column and one to two solid concrete beams between each column for seismic support. Very labor and material intensive structures! Floating foundations and floors are reinforced and poured thicker. The use a reinforced beams around the perimeter, and across the building. Less concrete, less labor and time to install. They only work with light buildings. In filled areas or beaches, heavy buildings use driven piles to provide support. Solid soils (not sand and filled areas), are far more stable, and supportive, making these foundations even stronger.
We utilize PEX plumbing, the standard for most construction in North America and Europe. It is the ONLY piping other than copper coils (think $$$) that can be used in a concrete slab floor according the IBC (International Building Code) that Panama subscribes to.
Compared to most other construction using PVC, PVC is a substandard product for use in concrete as it is brittle and can crack. It is not approved by the IBC/International building Code that Panama uses. It is “traditional” and up until a couple of years ago, not available in Panama. Water is scarce resource, even in Panama for several months of the year, and leaks in PVC piping under houses is an issues. Repairing these types of leaks is very expensive and invasive! PEX piping also reduces water use, especially water wasted while waiting for hot water.
Sewer system utilizes modern design reducing need to pump the septic tank often and allows for re utilization of all water entering the house for irrigation.
We use a standard leach field with a bio-digester septic system for the Black water. The bio-digester is approved by the Dept. of Health for effluent discharge to be utilized for irrigation. The kitchen is attached to a grease trap. All other fixtures are connected as a grey water system. Since only black water enters, the bio-digester, the system has no soaps or bleaches and therefore reduces the need to pump it.
The effluent can be diverted for irrigation using the two valves before the leach field. This allows all water entering the building a double usage if desired.
We also use sufficient sewer system ventilation which is uncommon in standard construction here. Proper venting is important for proper operation of toilets, laundrys, and other fixtures. Exterior penetrations are under eves, either in the roof or the walls. Proper ventilation is required for proper toilet and trap function.
We use romex wiring in these homes and is set up to easily facilitate conversion to solar and/or backup generator. Romex wiring is the system used in North America residential construction.
Compared to concrete wall construction, romex wiring is not compatible. These houses need to use a commercial conduit and wire system. This costs more in both materials and installation. The romex is installed with bushings in the studs and is consistent with North American and IBC codes.
The system has an extra box next to the main panel with a large diameter conduit to the outside to more easily access a generator or solar system installation. These houses are designed for easy conversion to off grid systems for remote locations.
The bamboo is treated bamboo. Please see the “Bamboo Treatment” page under BAMBOO. It is treated across the culm walls, so no further treatment is needed when cut. Posts are manufactured in forms using pre-welded connectors for the top and bottom of the posts. These steel connectors are cemented into the posts. The bottom is designed to be bolted to the foundation using bolts embedded in the concrete prior to pour. The top has pieces of all thread attached that is used to bolt down the roof sections
Roof sections are also made in molds, at a comfortable work height, on the floor and then lifted into place. This is not only easier to do and control quality, it is also safer and faster. This system is unique to bamboo and would be difficult to impossible to do in standard construction used here. We put on 3 ft overhangs to serve as walkways and for aesthetics. We cover these overhangs with treated Pine T&G, at a significant cost, for noise and aesthetics.
Zinc is the best choice for roofing. It is the most reasonably priced and the most problem free of the roofing systems, with the exception of possibly tile roofs, which are very heavy and expensive. Tile roofs are not problem free and do have their own set of problems.
Zinc roofing has two issues, it is very noisy in hard rains and it turns the suns energy into an infrared heat wave. Only sufficient insulation will reduce these issues. We use 2” of Styrofoam on the houses in Lemmon Grove Estates, if we were building in a hotter climate, we would either install screens in the cupola for natural ventilation, or 4” of Styrofoam if the building was going to be air conditioned.
Compared to the standard here, that uses a layer of R-1 roll foam, these houses are very quiet and cool.
There are a lot of aspects to affordable, efficient, environmentally sustainable design than just a floor plan. I hope this clarifies some of the considerations that go into the design of these homes.