spreading the word, USGBC edition

Next Saturday, November 16, the Miami-Dade branch of the US Green Building Council (USGBC) is organizing a tour of sustainable houses in South Miami and Coral Gables. They've graciously invited us to participate, and the USGBC bus should get to tin box around 1:30.

Besides the opportunity to compare strikingly different techniques for designing ecologically sustainable buildings, the tour will also offer insights into how public policy can make communities more livable, enjoyable and sustainable. Among the people speaking on the tour are Jennifer Korth, the Grants & Sustainable Initiatives Administrator for the City of South Miami, and Jenny May, the Chair of the Coral Gables Green Task Force.

You can register through this link.

batt insulation

We've had most of the interior walls filled with batt insulation. We're using the insulation to help reduce sound transmission from room to room. We're expecting a 5 point increase in the STC rating (of sound transmission) due to the additional mass in the walls. The Johns Mansville fiberglas batts are made without formaldehyde, which is important for maintaining our health, and are made with glass that is at least 25% recycled.

The insulation has also produced some nice spatial effects...

lumber

We've designed the house to avoid using softwood lumber as much as possible. This is the kind of wood that's typically used for framing (as 2x4s and 2x6s) or furring (the thin pieces of wood used to attach gypsum drywall to concrete block walls) in conventional construction. The two major problems with using softwood lumber in Miami are termites and mold.

However, it turns out we need to use a few 2x4s in the house...

shade

The cheapest technology in the house is borrowing shade from existing trees. We deviated from the US Green Building Council's LEED standards when we included lots of glazing on walls that face east and west. LEED's concern is that the low sun in the morning and afternoon brings excessive heat into a building during the hot months. We recognized, however, that the existing trees in the park to the west would provide a lot of shade in the afternoon, while our east neighbor's trees would shade the house in the morning. The photo at left shows the living/dining room shaded by existing trees, even before we add the roof panels.

termites

source: Google Maps

Besides mold and hurricanes, the other natural threat to buildings in Miami is termites. We frequently see tents draped over houses here - like our neighbor's house, seen in a GoogleMaps street view at left - so that they can be fumigated. The idea of fleeing our house for a few days so that it can be pumped full of poison is somewhat unappealing. What's more, the treatments often only work temporarily; the same neighbor already has termites attacking his house again. So what can we do to avoid this?

embodied energy and energy use

“Statistics are merciless things.” Le Corbusier, The City of To-morrow and its Planning, 126.

The Department of Energy has posted a lot of useful data on energy use in the United States, which helps identify the low hanging fruit for big gains in energy efficiency. Some of the key take-aways: Americans consume one fifth of the world’s energy. Two-fifths of that energy is consumed in and by buildings, with 22% going into our houses. 91% of that energy produces carbon or radiation. And, most depressingly, nearly half our energy is lost in transmission and distribution.

site visits

One thing we like about the LEED process is its emphasis on education. The USGBC knows as well as anyone that sustainable building practices need to be widely known in order to be widely used. Clients, designers and builders need to know about alternatives in order for us to change decades of habits, customs and traditions. And thus was born this blog.

But we also see tin box as an opportunity to exceed LEED’s education requirements.

concrete details

As we've noted before, our concrete foundation and slab have some interesting sustainability aspects. Half the cement portion of the concrete mix has been replaced by blast furnace slag, which means an industrial waste product has been substituted for virgin material (in our case, that means more than seven cubic yards of recycled material). The slag will make the concrete denser and harder once it has fully cured.

The steel anchor bolts will hold the steel columns in place. The bolts are embedded deeply enough (20" - 27") to secure the house, even during a category 5 hurricane. Some of the bolts moved a bit during the concrete pour, so they'll need to be "adjusted" with a sledge hammer before the columns can be erected.

cabinetry

Met with our cabinet maker, Kaelsie Saravia of Surface Workshop, this morning, and picked up two big samples of bamboo plywood. This is probably the material we'll use for the kitchen cabinetry, and it'll bring some warm color and rich texture to an otherwise cool, smooth palette of steel, glass, concrete and gypsum board.

The "plywood" is made by Smith & Fong under the Plyboo name, and has three great attributes from a sustainability standpoint: it is made from fast growing bamboo, not trees, it is made without formaldehyde, and it is very durable. Aesthetically, it is gorgeous, and its grain makes it easy to disguise the slight inconsistencies from board to board, which will allow us to build a run of cabinetry over twenty feet long that looks like it was made from a single batch of (far more expensive) matched plywood.

that new house smell

Formaldehyde causes cancer. Architects and environmental activists have known this for a long time, which is why the indoor air quality portion of LEED requires us to use materials that do not include added formaldehyde. Yesterday, the federal government’s National Toxicology Program finally confirmed this fact in their latest Report on Carcinogens.

productive landscapes

The intoxicating, thick scent of rotting mangos in the back yard is triggering more thoughts about food in the domestic landscape. One question we’ve been grappling with at tin box is the extent to which we’ll use fruits, vegetables, herbs and spices in our mix of plant species.

shop drawings

Ecosteel sent us 359 sheets of shop drawings on Friday. These are drawings that will be used to fabricate the steel framing members for the house. They are intricately detailed, and are based on a detailed three-dimensional model.

There are ten sheets of plans and elevations (showing the house as a whole), which are keyed to 233 sheets of details (which show the complex steel structural members built up out of smaller pieces), which refer to 116 sheets showing those smaller pieces. It is like looking at the directions for the world's biggest model airplane kit.

noted at the basketball playoffs

Clearly influenced by our work here at tin box, the American Airlines Arena is proclaiming its LEED certification from the rafters. Literally.

This is particularly impressive for a venue that shoots flames into the air during player introductions.

red, white, blue and purple (plumbing, p.4)

A closer look at the rough plumbing. A normal house would have one set of big PVC pipes for waste, and two sets of smaller copper pipes for hot and cold water. What's different here? A few things...

successful failure

One of the recycled materials we wanted to use in tin box was shredded tire. Used tires are a nasty waste product, but in recent years Florida and a few other states approved the use of shredded tires as a replacement for gravel in places like septic drain fields. We wanted to do just that, but after a little research, we found that waste tires are getting snatched up for more lucrative uses: playground mulch and cement plant fuel. This, of course, is disturbing to us at one level - we won't get to use tires, dagnabit! - but deeply satisfying at another - recycling tires has become profitable, with several industries competing to purchase what was once a semi-toxic landfill material.

plastics

For forty-four years, the future has been defined by a word: plastics. Our buildings are full of plastic materials, and tin box makes use of three in particular: polyethylene, polypropylene and polyvinyl chloride. Two of these materials have serious environmental benefits. One is a known killer. All three have their plusses and minuses.

footings

Our concrete subcontractor poured the foundation footings today. "Footings" is an ambiguous term, since it can mean both the full foundation piece supporting the steel column, or it can mean just the broad pad that supports the vertical piece of the foundation (the pedestal). In our case, we just poured the bottom half, which takes the weight of the column and spreads it out while transferring it to the ground.

The cage of steel rebar inside the concrete handles the tensile forces within the footing, while the concrete takes care of the compressive forces. From a sustainability standpoint, the steel is almost entirely recycled, and the concrete mix includes steel blast furnace slag as a replacement for half the cement that would ordinarily be used. The aggregate and sand that comprise most of the concrete mix are produced locally, to minimize the embodied energy that comes from transporting materials.

slag

An interesting turn of events. We had planned to use fly ash - a waste product of coal-burning power plants - as a replacement for 25% of the cement in our concrete foundations and slab. Our concrete supplier, however, recommends using slag (ground granulated blast-furnace slag) to replace half the cement in the concrete mix. Slag is a waste product from steel production, which, magically, works a lot like Portland cement, so using it in the foundations will obviate the need for more virgin cement and find a useful home for an industrial waste product.

walkability

One of the major factors in our decision to live in South Miami is the town's walkability. Walking is an essential part of building community - the streets we share with our neighbors are the civic realm in which we participate in everyday democracy. There is a fundamental difference between cities where you can walk, and cities where you cant. Cities with a rich pedestrian life have more cohesive bodies politic. After all, where do you have a Fourth of July parade in suburbia?

So how do you measure walkability?

community resources

One of the criteria that Leadership in Energy & Environmental Design (LEED) emphasizes is a building's proximity to community resources, such as schools, public space, shopping, cultural institutions, recreational facilities, public transit, workplaces and houses of worship. The idea - and one we endorse - is that proximity to these resources fosters a sense of community by encouraging neighbors to walk or bike, rather than drive. This also has obvious environmental benefits.

One reason we chose this site was its adjacency to a lovely park. Note the excellent tree swing. Even if we don't spend much time in the park, however, we see it as a great value to us for its ability to engender community by providing a place for our neighbors to gather and play.

We'll blog more on LEED, later.