Architecture, Engineering & Planning EVstudio | Denver & Evergreen Architect | Colorado & Central Texas | Blog

EVstudio.info has Moved

Sean O'Hara — Tue, 28 Feb 2012 05:07:21 +0000

This is planned to be the last new post on EVstudio.info. We've moved and merged with the EVstudio.com blog. Check out the new home at www.EVstudio.com/blog.

CNU’s Highways to Boulevards Initiatives

Sean O'Hara — Thu, 19 Jan 2012 21:06:47 +0000

I recently was part of a conversation with the Congress for the New Urbanism's President, John Norquist, about the proposed changes to the elevated section of I-70 in Denver. He pointed us to the CNU Highways to Boulevards Initiative website. There are several great examples on the page of sections of highway (often elevated) that were built cutting through urban fabric, that are now being closed or otherwise rethought.

Originally posted 2011-10-11 01:49:22.

CNU Colorado is an Official Chapter and Photos from the Norquist Lecture

Field Drilling Holes in Laminated Veneer Lumber (LVL) Beams

Adam Denton — Thu, 19 Jan 2012 21:06:46 +0000

Laminated Veneer Lumber (LVL) is a manufactured structural wood product that is utilized when the strength requirements of a timber beam exceed that of your typical sawn lumber beam. LVLs are produced by taking wafer thin slices of wood and sandwiching them together (see photo below). Each slice of wood is oriented with the grain perpendicular to the slice next to it. The “sandwich” is then held together with a high strength epoxy. The result is a timber framing member that is not only superior in strength, but can be purchased in lengths of up to sixty feet while staying straight as an arrow. Finding a 2x8 longer than ten feet long at your local lumber yard that isn’t warped would be a difficult task.

Laminated Veneer Lumber

In any construction project, especially new additions to homes or commercial buildings, there is a limited amount of space to run utilities such as electrical wires or water pipes. Sometimes the only available option is to port these utilities through the beam. As with all timber construction, a square hole should never be cut into an LVL beam. Square cuts develop stress concentrations and are prone to splitting. Round (drilled) holes are preferred because they allow stresses to develop “more smoothly” around the opening. As a beam is loaded, stresses concentrate in different areas. Knowing this, the APA (The Engineered Wood Association) has created the illustration shown below as a field guide to the most desirable places drill holes in LVL beams. Please keep in mind that it is always safer to consult your licensed structural engineer when modifying any load bearing member.

From the APA document "EWS G535A"

The EWS G535A is a free publication from the APA which goes into much greater detail than presented here. The APA’s website is a great resource for builders, engineers, architects and home owners who are looking for information on manufactured lumber products.

Originally posted 2010-07-02 00:01:07.

The Santa Fe Style – Blending Pueblo and Territorial Architecture

Beth Concha — Thu, 19 Jan 2012 21:06:45 +0000

The Santa Fe style is a variation of both the Pueblo Revival and Territorial Style of architecture, made popular in the late 1800s. It became the standard in New Mexico after it was defined by the Santa Fe Historic Zoning Ordinance of 1957. The ordinance mandated the use of the Pueblo or Territorial Style on all new structures, (buildings and residences), in central Santa Fe.

The Pueblo style was originally constructed with sun-dried adobe blocks, but modern-day structures are typically concrete block or wood-frame covered with stucco. Typical Pueblo Style characteristics include flat roofs with parapets, vigas (originally structural, but today mainly decorative), enclosed patios or courtyards, one level with varying plate heights, rough-hewn wood lintels above windows and doors, canales (roof drains), decorative wooden corbels, interior art niches, and courtyards.

The Territorial Style has many of the same elements as the Pueblo Style, except it is more straight-lined. Smooth stucco is used as opposed to the usual rough finish. Brick coping is traditionally used atop the parapet walls to protect from water damage and to create a more clean-lined effect, something not normally seen in the Pueblo Style. Milled woodwork details are also commonly found, including pedimented lintels above window frames, and elaborate dark wooden trim. Unlike the consistent earthy tones of the Pueblo Style, the Territorial Style may include brightly painted features such as a blue front door.

Today, it is difficult to find examples of each individual style due to the fact that the Santa Fe Style combines design elements of both.

Originally posted 2009-10-24 00:02:33.

The Five Minute Walk: Calibrated to the Pedestrian

John Olson — Thu, 19 Jan 2012 21:06:44 +0000

The traditional neighborhood includes a high level of connectivity allowing actual walk distances to nearly meet the 1/4 mile radius.

The Five-Minute Walk is a standard that is best described as the average distance that a pedestrian is willing to walk before opting to drive. The unit of measurement is commonplace in the planning profession and is often represented by a radius measuring ¼ of a mile. The average walking speed of a human is at approximately 3 miles per hour, which translates to ¼ of a mile in five minutes. Most planners, admittedly including myself, often represent the walking distance on a proposed plan drawing or an aerial as a circle drawn with the center of the circle on the destination. The circle is most often represented as 1320-feet radius.

The conventional suburban model of development provides very little connectivity from the residences to the places of business making it very auto-dependent.

The problem with this basic diagram is that it does not take enough into account. The ¼ mile radius circle shows the distance ‘as the crow flies’ or as a linear route. Pedestrians tend to utilize sidewalks, whereas a drawing with a ¼ mile circle cannot represent this. Major arterials, fences and walls are also commonplace in suburban locations limiting the walkability even further. I have included a couple of diagrams in Colorado Springs, one of which is for a neighborhood coffee shop in a Pre-WWII neighborhood, which I will refer to as a traditional neighborhood, and the other is in a first ring suburban area of Colorado Springs, or conventional suburban development. Notice that the traditional neighborhood diagram is set up on a well-connected grid of streets, whereas the other diagram includes the quintessential auto-centric street layout common in suburbia. The traditional neighborhood has multiple intersections, allowing more access from the pedestrian. An area with a great amount of intersections per acre and short blocks will be better suited for walking than an area with few intersections and long blocks. The conventional suburban neighborhood is set up with a definitive hierarchy of streets, limiting the accessibility of potential walking consumers.

The two diagrams provided illustrate in a black dashed line actual distances of 1320-feet via the pedestrian. Notice that the outer circle in the diagrams does not come close to accounting for the actual walking conditions. As planners, we need to be careful how we represent the five-minute walk as it can be very misleading.

Originally posted 2010-09-07 09:10:33.

Evergreen All Kids Dental Wall Locations Walk Through

Living a Radiant Life – Understanding Radiant Heat Transfer in Buildings

Dean Dalvit — Thu, 19 Jan 2012 21:06:43 +0000

Radiant Energy. Something that is so widely misunderstood, and yet has such a tremendous impact on our daily comfort. I have been doing some home study and experimentation in the field of radiant heat transfer in the context of a typical home's heating and cooling needs and have stumbled across some truly revolutionizing concepts that rarely before have been considered for mainstream practice. Now, these ideas expressed in this post may still be theoretical in nature, but we hope to qualify them in time and in practice so we can utilize the physical laws of nature to our advantage.

First of all, I have to say that the core item that started the snowball effect of my thinking came from a simple object in my son's camping first aid kit: the space blanket. As first sight, I thought to myself, how could this paper-thin foil "blanket" (if you could call it that) possibly keep you warm. Upon further experimentation, it turns out the thing actually works remarkably well. Giving credit where credit is due, the folks at NASA really know what they're doing here. Now, it is important to note that while the space blanket will effectively reflect the body's radiation back to the body, those other modes of heat transfer (conduction and convection) are still at work, so if you are lying on a snowbank with a space blanket on, you will still arrive at the doorstep of hypothermia.

But enough about backcountry survival tips. The idea went from the simple space blanket very quickly to the idea of a space blanket for the home. I have posted before about heat loss through convection and conduction, and even how thermal mass plays into that equation. But I have spent relatively little time to date explaining the effects of radiant heat transfer for buildings. As it turns out, it is quite astonishing, and may really challenge conventional construction practices as we move forward into the 21st century trying to design zero carbon footprint homes and zero net energy buildings.

The basics are this: All objects radiate heat energy from themselves in all directions all the time through the mode of electromagnetic waves of energy. The hotter the object, the more it will want to radiate, however there is a very important material property that also describes how much the object "wants" to radiate. That property is called emissivity. Now, without going into the mathematics of Stefan's Law or it's derivative proofs, suffice it to say that it exists and explains why we feel thermal comfort or discomfort in different environments.

The basic outcome of the physics behind emissivity is this: If you stand near a warm object that has a reasonably high emissivity, then you, in turn will feel its warmth regardless of the air temperature that separates you and the object. Now, obviously, conduction and convection are still players in your comfort, however, if you are absorbing that heat from radiation, the surrounding air temperature can be significantly colder than what you would expect the appropriate comfort range to be. Anyone who has gone spring skiing in the rockies can attest to this fact as their sunburned bodies are exposed to the high altitude spring sun and feeling quite comfortable, while the surrounding air temperatures are still in the 40s and they're standing in a giant snowfield at an even 32 degrees. By the way, that snow field does a pretty good job at reflecting the sun's radiant energy to that sunburned body as well (so don't forget sunscreen under the chin).

So, getting back to our space blanket, the core idea is a simple one: If you can keep your body from releasing all of it's radiant energy to its surroundings, then you will be considerably more comfortable without having to add additional heat. Well, until we are all brandishing space blanket clothing (which will be my next business venture to be sure), we need to figure out how to get the buildings that we occupy to perform the same function.

If we can provide a building skin that can reflect as much of the radiant heat back into the space during the cold winter months, and release it to the outside during the warm summer months, we will have solved the radiant problem of buildings. Now, I would be perfectly satisfied with a permanently reflectant interior shell and an open window when the weather requires, but that is partly because I live in the mountains of Colorado and I prefer fresh air cooling in a climate that will allow for it. Someone in south Florida has different environmental factors, but we would simply apply all of these physics in reverse for that climate.

Consider the temperatures of the objects in your home. If the mode of heating is gas forced air, then you are probably uncomfortable most of the winter. The reason for this is simple. It takes a tremendous amount of warm air (or a significantly hotter amount of air) to heat a solid object. Here is a simple relationship that I calculated this morning (and I would be happy for anyone else to corroborate this simple analysis). I call it "The Spaghetti Pot Example" and it goes like this: In order to heat a spaghetti pot of water (1 cubic foot for the scientists in the room) by 1 degree, it is equivalent to heating the entire volume of three bedrooms of air (each 12'x12'x8' in dimension) by one degree. The implications here are really quite staggering. This, in a nutshell explains why radiant heating in any mode is going to be more effective than heating air to provide thermal comfort. Whether it's the floor that you heat, or radiators, or even a Franklin Stove, the heated objects are easier to heat and can carry much more heat per unit volume than air can.

It seems I may be getting off the subject of radiation, but this is actually the crux of the entire radiant space blanket discussion. It is this: We already have most of the heat energy necessary within our homes (and our bodies) to keep us quite comfortable in the cold winter months, if only we can efficiently contain it and manipulate it. By the Spaghetti Pot Example above, it can actually be inferred that you can open your doors in the winter and let all of the heated air out of the home as long as the heat is contained within the objects of the room, because the air carries a significantly smaller amount of heat within the home than the heated objects and building materials themselves. I do not encourage you to do this because it is still terribly wasteful, however, it is far more wasteful if your heating mode is gas forced air because there are fewer heated objects in the home to supplant that lost heat (only those heated by the warm air). In the gas forced air scenario, you're throwing all of your heating dollars out the window...literally, because doors and windows account for the largest piece of the energy loss pie within any building. There is something to be learned here.

What is that lesson? Heat your building with a radiant mode of heat that will actually heat the dense objects and building materials within the building. Use thermal mass within the building. Control radiation loss at the shell of the building. Also, I don't want to diminish the high value of controlling conduction and convection losses in that shell as well, but the point of this post is really about radiant heat control.

So, how can we make a thermal blanket around the shell of a building? That question will require a lot more research and development, but I can tell you that in the next building I design, I will consider finishes for the interior of the shell that are reflective in the infrared spectrum (IR). Building grade foils and IR reflective (aluminum based) paints like this are already in use with some radiant heating systems under the floors and I propose to use these relatively low-cost and easy to procure materials around the interior skin of the building, whether the exterior walls are cavity with insulation, SIPs, ICFs, or any other building type. With emissivities around .03 (very reflective), this skin can effectively reflect the radiant heat back into the home, saving a significant amount of radiant heat loss, while also directing heat directly back to the occupants (with emissivities around .9 - very absorptive). Low-e windows that have been available for some time also take this very phenomena into account and we are seeing significant enhancements to building performance by using windows that reflect the radiant heat energy back into the home. At the same time, it is vitally important to consider highly absorptive finishes for interior elements that have thermal mass or are a part of the heating delivery system for the building. Floors, interior walls, built-in objects and even furniture. In some cases, the exterior walls may also play a role in that thermal mass as well. Every building construction and configuration is different and will require its own analysis. The point here is that these are must-have technologies for every building we build from here on and should become standard details for our design.

As we continue to learn more about the science behind these concepts, and commit ourselves to looking forward into 21st century design and construction (rather than repeating the errors of our past out of convenience or ignorance), we will be able to develop truly revolutionary new details with relatively simple and cost-effective solutions that will take sustainable and energy efficient design into a completely new stratosphere. I encourage everyone to test and challenge these principles and ideas in order to further innovation, as I too am committed to this search for knowledge in order to drastically improve every building that we design.

Originally posted 2008-11-09 12:24:52.

Cost of PV – Photo Voltaics

Dave Buesser — Thu, 19 Jan 2012 21:06:42 +0000

The Lawrence Berkley National Lab just released (9/2011) a study titled “An Historical Summary of the Installed Cost of Photovoltaics in the United States from 1998 to 2010” (a very clever, concise and subtle title I thought).

Though lengthy it included many interesting bits that I found interesting and worthy of further summary:

Predictably, the costs are headed down with costs before direct financial incentives down from $11/W in 1998 to $6.2/W in
2010. This represents an annual cost reduction of about $0.40/W per year.
From 2009 to 2010 the average installed cost went down 17% ($1.3/SF)
Costs are still declining in 2011.
Colorado accounted for 3% of the national PV capacity additions in 2010.
The costs vary widely by state due to permitting requirements, labor rates, tax exemptions, etc. Among the less than or equal to 10kW systems completed in 2010, the average costs ran from $6.3/W in New Hampshire to $8.4/W in Utah.
After incentives in 2010, the net installed cost (after incentives) of commercial PV averaged right at $3/W. While for residential it averaged $3.6/W

The decreasing costs make PV an increasingly interesting option as a source for on-site renewable energy and for owner’s looking to pursue net zero.

Read the whole study at:

http://eetd.lbl.gov/ea/emp/reports/lbnl-5047e.pdf

Originally posted 2011-09-22 10:33:58.

When is a Stage a Platform in the International Building Code?

Sean O'Hara — Thu, 19 Jan 2012 21:06:41 +0000

One of our current projects is the renovation of the gymnasium at the Denver Montclair International School to add a stage at the end of the gymnasium. The stage area is approximately 1,090 square feet. In the International Building Code a "stage" over 1,000 sf triggers a number of requirements for construction including a standpipe, sprinkler systems, fire separations and stage ventilation.

What we needed to do was have the stage area properly classified as a "platform" rather than a "stage" which makes many of the requirements go away. The difference in the definition is that platforms cannot have "overhead hanging curtains, drops, scenery, or stage effects other than lighting and sound". By removing the main curtain we were able to get the building department to permit the renovation without the additional cost of the additional requirements.

Now, that being said, the purpose of having the stage area reclassified is to more clearly reflect the actual use of the space. I would not advise a client to reclassify it if they intended to use it for full scale productions with a high occupancy. In this case the school is using it for small audiences and small classes and doesn't have any plans for drops or anything that requires the additional code protections.

The interesting battle for another day is about any future curtain. The section about the automatic sprinkler system clarifies that sprinklers are not required on stages where curtains, scenery or other combustible hangings are not retractable vertically. The Denver building department was fine with this section allowing a traveler curtain but the Fire department references the International Fire Code which does not have exactly the same provisions.

Originally posted 2010-07-11 17:18:09.

Solar Hot Water Radiant Heat

Anthony Ries — Thu, 19 Jan 2012 21:06:40 +0000

I was recently asked about heating a home with a radiant floor heating system that utilized solar hot water. This seems a counterintuitive at first since the sun only shines during the day and it shines for less than 12 hours during some of the coldest times of the year. However, we have to remember one of the key concepts of passive design: thermal mass. So it is possible to do when the home is designed for it.

Key factors to keep in mind:

Thermal mass. This system works best with a 4-6 inch concrete slab with some insulation beneath to help regulate the concrete temperature. The thermal mass can help cool the home in summer.
Maximize solar collectors for the coldest months in your climate.
Maintain water circulation. It is possible to rely on thermosiphon, the natural tendency of warm water to rise and cool water to sink, to keep the system working. However, it is always a good idea to have a backup pump just in case.
Back-up boiler. You don’t want to get stuck in a cold house. A boiler can be configured to only kick-in if the water in the system falls below a specified temperature.
Protect the system from freezing. It is possible in cold climates for the water in the solar collector to freeze. Non-toxic Propylene glycol can be used on the system to reduce the already lower freezing temperature of moving water.
Orientation. Good solar access for the panels and buildings should be part of the overall building design. Most windows should be placed in the south facing walls for direct solar gain in winter. The east side should have the second most windows to aid early morning heat gain. West and north facing windows should be minimized or eliminated in order to minimize afternoon overheating and general heat loss, respectively.

These are the primary concepts for a successful solar hot water radiant heating system. As always, for any alternative system to be successful it is best to incorporate it into the project as early as possible so that it is wholly integrated.

Originally posted 2010-02-18 00:01:13.

Boulderspace

Sean O'Hara — Thu, 19 Jan 2012 21:06:39 +0000

I just ran across the Boulderspace blog.

Well worth a look, lots of architecture related topics and its more than just Boulder.

Originally posted 2008-10-10 02:19:57.