A 5/8" diameter wedge style expansion anchor.

There are many situations were it may become necessary to attach a timber ledger to a concrete wall. It is desirable in many new homes to lower the elevation of the finished floor to make a home more wheel chair accessible. An example of the differences between the finished floor elevations that can be achieved with a framing ledger are shown below. Additionally, when an addition is made to a residential home a timber ledger is installed so that the finished floor of the new construction can match the finished floor elevation of the existing construction while utilizing the existing foundation wall.

Conventional Floor Framing vs. Ledgered Floor Framing

Wedge style expansion anchors work because of the friction forces developed between the studded collar (see photo at top) and the concrete. To begin a typical installation a hole must first be drilled into the concrete. All manufacturer’s instructions for hole size and depth should be followed carefully because the recommendations will vary between bolts sizes and manufacturers. Once a hole is drilled and cleaned the anchor may be driven into the hole with a hammer. The studs on the collar are slightly larger than the widest diameter of the bolt so initial contact with the concrete is only at these areas. Once the bolt is driven to its specified depth a pre-drilled timber ledger may be installed over the bolts. Finally, the nuts (with supplied washer) may be installed. As the nut is tightened, the studded collar with catch on the edges of the hole in the concrete and will be forced onto the wedge. The collar will expand as it is driven onto the wedge creating a greater frictional force against the concrete. With the nut installed to the proper torque the anchor may be safely loaded to the manufacturer’s design specifications.

According to the USGBC Website: “The Licensed Professional Exemption (LPE) is an optional credit documentation path in which professionals can submit license information and a declaration of compliance in lieu of a number of otherwise required submittals." The LPE basically shifts the responsibility to the professional rather than the submitted documentation and is meant to help streamline the documentation process required for LEED Certification. The documentation required for LEED Certification has been the target of much dissent from both opponents and proponents of the program since its inception a decade ago. On the surface, the LPE compliance path does have quite a bit of potential and may end up ultimately reducing the extensive amount of documentation required for a LEED Certification application but the jury is still out on the usability of the Exemptions. The lack of collective experience from professionals working on LEED projects who have opted to use this compliance path, coupled with the lack of documentation from the USGBC explaining how LPE will ultimately work once a project has reached their review and certification process is causing the said licensed professionals to understandably worry about liability concerns.

According the Green Building Certification Institute (GBCI) website, all Licensed Professionals may provide their license information when registering for an account with LEED Online or by updating their existing account information. They must provide all of the information applicable to each license that they intend to submit information under including name, professional category, license number, the country, state, territory or province issuing the license and the license expiration date. They must also indicate that they are in good standing and agree that they have the technical competence and expertise necessary to oversee and verify the technical work required for compliance with the criteria for which they are submitting. The provided information is then retained with the user’s LEED Online account and can become applicable for submittal documentation on any LEED project in which they are involved. The liability concern enters the picture with the following warning provided on page 9 in the official GBCI Policy Manual:

The Licensed Professional is not only taking on liability for the achievement of the LEED credit or even the LEED certification, but also risking potential disciplinary action against their licensure.

The extensive documentation necessary to complete LEED application and certification, along with the time and money required to accomplish the documentation alone remains one of the biggest hurdles for the LEED Program. Unfortunately, it still remains to be seen as to whether or not the largest step that the USGBC has taken to mitigate the problem through the LPE Compliance Path actually delivers a viable solution.

Performance and long term total cost.

A post tensioned concrete slab on grade requires little maintenance compared to a asphalt or mildly reinforced concrete slab.  In addition, post tensioned slabs do not require control joints in the slab, giving the players a smooth surface over the entire court.  Many asphalt and mildly reinforced courts begin to have cracks and noticeable movement with in 5 years of construction.  These slabs require expensive maintenance and become an eyesore.

The reason post tensioned slabs outperform other methods is because concrete performs well under compressive forces, but fails under low tensile forces.  By adding compressive forces into the concrete with steel cables the slab becomes stronger and able to resist soil movements where other methods would otherwise fail.  A simple way to image this concept is placing 4 small wood blocks in a row.  Then place a rubber band around the wood blocks.  The 4 small blocks are now held together and act as one block.

Using the same example of 4 small wood blocks, an asphalt court would be holding the blocks together with rubber cement and a mildly reinforced concrete slab would be holding the blocks together with a string glued through small holes in the middle.  Although the blocks are held together you can still imagine you could bend or pull the blocks apart easier than the 4 blocks with a rubber band.

To achieve sufficient performance a minimum residual compressive force of 100psi  is used.  This is the rubber band force mentioned above, but much greater.   The 100psi force is typically achieved by spacing steel tendons 30" to 36" on center and stressed to 33,000lbs.

For more information refer to the PTI Design and Construction of Post Tensioned Sport Courts.

Here's what Mountain and Urban properties have in common:

The largest scope in the set of residential permit drawings is the Architectural and Structural design – the core of the set of plans for the home. This includes everything about the home itself, from the initial programming, the design concepts, floor plans, elevations, sections, electrical lighting and switching layouts, to the structural engineering of the foundation plan, floor and roof framing plans and all of the necessary details for the builder to build the home. While local climate and regional location drives a multitude of design parameters, these core documents are largely the same for mountain and urban projects.

Also required these days by any jurisdiction adopting the new International  Energy Codes will be a Manual J, Manual D and a Rescheck energy model for the home's energy performance and heating system design. These documents are not typically a part of the architectural drawings as they are most often provided by the HVAC system installers or separate MEP engineers. Be that as it may, expect to see these requirements for permitting any home, rural or otherwise, and find out the cost of these services up front.

A geologic soils report in the general location of the proposed structures will also be necessary for any project in order to determine appropriate soil characteristics for the design of a foundation. Mountain properties are often in geologic zones that have few issues with soils, however pockets of unusual strata can be encountered anywhere, so at a minimum, the soils should be examined by a professional during excavation. These services need to be coordinated, and can be costly, depending on your location, so find out what the impact will be early on to eliminate unhappy surprises.

Urban Living

Most jurisdictions are now requiring stamped and sealed truss drawings prior to releasing a permit. While this practice is questionable because field changes can drive changes to shop drawings, and cause confusion during framing, the International Residential Code is clear on it's requirement for permitting. Some jurisdictions will grant a conditional permit, requiring these drawings to be submitted prior to framing inspection, which is much more reasonable. Truss drawings should be coordinated by the structural engineer and provided by the truss company as a part of the truss package, so it would be unusual to incur a separate design fee for this scope.

It is always important to have a property survey, showing the property boundaries, easements, setbacks, any improvements, and spot elevations around the site in order to determine building heights, location and orientation, and ensure positive drainage around the building. Understanding what entitlements and encumbrances on a property are crucial to understand. They are itemized on a title commitment, and should be a part of any survey. Do not take anything for granted or assume anything about the lot without documentation. Survey costs vary significantly with lot size and survey complexity, so be sure you know what your site will entail.

In addition to the above requirements,  a mountain project will also require the following additional documents prior to release of a building permit in most jurisdictions:

A more detailed topographic survey of the portions of the property will be necessary for the design. This is critical for larger lots where steep grades can be encountered. Driveways need to be designed to exacting standards, and existing topography will drive what can and cannot be done. Steeply sloping sites will also drive design of the home and any other structures as well. Other site elements include large trees, rock outcrops, wetlands areas, riparian boundaries, and any other natural features found on the site. Documenting these features not only helps to preserve them for the enjoyment of the owner, but also to enhance them and integrate them into the design. These elements do add complexity to the survey, and the lots are generally much larger, so expect a sharp increase in costs for these kinds of surveys.

Civil Engineering necessary for a driveway and/or grading permit will also likely be required. Because of larger lot sizes, driveways really become private roads and the amount of site disturbance required to get to the building site can be significant. Civil engineering documents for the driveway design, erosion control plan, and grading plans all are necessary for the proper design of the driveway, emergency access, and also help to identify potential issues. This is a scope largely unseen in urban environments, unless you're developing commercial property or tracts of land.

Mountain Property

For lots without utilities, a full Septic design will be required for the site. This will outline the septic tank and leach field based on the number of bedrooms in the home. Careful design of the septic field will ensure longevity of the system, but also protect underground water from contamination. While you will enjoy the value of not having to pay for tap fees, the design and installation of the sewer system will be no small number, so be aware of these requirements. Also note that most jurisdictions are not very keen on "alternative methods" of waste disposal. Any effort to propose things outside of the norm will require more engineering proof to the department for its acceptance.

You will also need to demonstrate proof of water for the site. Again, most rural mountain lots will not have a metro district nearby, and therefore, you will need to show that a well can legally be drilled, and also that the well can produce a minimum amount of production prior to a building permit being issued. While the amount of water necessary to support a home is a highly debatable issue, the fact remains that you will have to prove you have water before they will let you build. The well design often comes with the septic design as the two are related. However, the cost of the well and the cost of the septic installation are two different line items, and akin to their respective tap fees on urban properties.

Often taken for granted, you will also need to demonstrate that you can legally access the site. On urban lots that have been developed, this issue rarely comes up, but on mountain property, there are often parcels that result from illegal subdivisions that can orphan interior lots. Our advice: Do not buy one of these properties unless you know with certainty that the issues can be resolved and necessary easements granted. The survey for the property may need to be broad enough to demonstrate this proof of access, or the title work will need to identify the appropriate easements necessary to legally access the site.

This is not an exhaustive list, and there are many more considerations to be aware of when dealing with mountain property. If you are considering building a home in the mountains, it is best to get help selecting the right site before you even make an offer. While it is unusual to hire an architect before owning a lot, our real estate department offers these services at no additional cost. Give us a call and we can help you select the right property for the perfect home.

For any structural member deflection limits must be satisfied based on the building code.  For floor joists a live load deflection limit of L/360 and a total load deflection limit of L/240 must be met.  For example, a floor joist spanning 20ft (240 inches) a deflection limit of 2/3inch for live loads and 1inch for total loads.  This is the maximum deflection the designer should meet but it is only a minimum requirement.  Some homeowners may notice this deflection and complain about bouncy floors.

To provide higher quality floors for homeowners a deflection limit of L/480 is commonly used.  For the 20ft floor joist example the new deflection limit is now 1/2inch.

iLevel has taken this one step further by creating their TJ Pro Rating.  The TJ Pro Rating is based on satisfaction percentages of homeowners.  Below is some information provided by iLevel.

TJ-Pro™ Ratings factor in the human element in designing floors.
How a floor feels to a home buyer has always been subjective. Yet making floor performance predictable is exactly what we at iLevel have done. We invested over 10 years of research into “real world” floor situations and tested hundreds of floors that were built to precise deflection characteristics. Then we had thousands of people walk on them. We captured their preferences, put the information into a computer model and analyzed the data. TJ-Pro™ Ratings are the result. Based on the number of people who preferred one floor to another, we assigned a performance number. Our proven software programs use this information to analyze your design and assign it a performance number that is typically between 25 and 65. The higher the number, the more likely a home buyer will be happy.

There are six basic concepts to any successful use of daylighting. In this article we will cover the first two.

• Separate apertures for vision and daylight
• Make the building act as a luminaire
• Assess lighting needs for typical visual needs
• Use of apertures to create focus and mood
• Integrate the daylighting scheme into the architecture
• Integrate the daylighting scheme with building systems

Separate apertures for vision and daylight

I want to start with the biggest mistake that is made when implementing daylighting. Namely that ribbon windows or large expanses of glass equate to effective daylighting strategies. Nothing can be further from the truth.

If you have ever sat near a south facing window on a warm spring day you know what I am talking about – solar heat gain. While it can be interesting to watch a sun beam move across the room, it isn’t very useful once that beam strikes the paper you are reading or creates glare on the monitor. This type of glazing is typically referred to as “vision glass” as it creates the visual connection between the indoors and out doors. Here we often specify a lower visible transmittance in order to soften the light coming in. Additionally exterior features such as overhangs can be used to minimize direct sunlight through this glazing.

The other type of glazing is referred to as “daylighting glass”. This type of glazing is placed at a higher level, typically above head height. These windows also utilize lighting controls such as internal or external light shelves or other devices that reflect light into the space. These devices should disallow a direct view and also bounce the light into the space so that it is indirect and thus more evenly distributed. With this glazing we typically want to maximize visible transmittance so we can get the fullest amount of daylight into the space.

Make the building act as a luminaire

Good daylighting minimizes the need for supplemental lighting during daylight hours. In order to accomplish this, the building needs to be able to provide consistent interior lighting levels. This means that the design should avoid the use of direct illumination (see above) and maximize the use of the skydome. The use of indirect daylighting, versus the sun directly, reduces glare and high contrast ratios, something that good luminaire design does as well.

This is also where proper finish specification comes into play. We want to direct the light as far into the building as possible. To do this it is best to use light colored surfaces that have a matt surface. This diffuse reflection helps to, you guessed it; reduce glare and high contrast ratios.

By using the skydome as opposed to the sun it is also possible to provide for more consistent lighting levels throughout the day. The best way to reduce solar heat gain and glare is to use the northern skydome. The southern area can be used when designed carefully. It is usually best to avoid east and west apertures because it is difficult to control the early morning and evening sun.

Be sure to bookmark the EVstudio Online Magazine to read the next two articles in this series.

EVstudio's Structural Engineers are working with Earthcore SIPs LLC to provide high quality SIP walls, floors, roofs and foundation walls to meet every client’s need.  EVstudio's role will be to provide structural engineering services for each project, provide detailed shop drawings and provide engineering reports for all of Earthcore's products. 

Earthcore manufactures SIP walls, floors and roofs using OSB or Magnum Board facings and a polyurethane foam core.  The polyurethane core provides insulation R-values of roughly 7.0 per inch of thickness, higher than commonly used polystyrene.  Earthcore uses Ecomate® foam which has a water based blowing agent. This eliminates all CFC and HFCs in the product which makes it one of the most environmentally friendly foams available.  In addition, the polyurethane bonds directly to the facing and wood plates providing a much stronger composite system without the use of additional adhesives.

Magnum Board can be used in lieu of OSB facings to create a panel that can be used below grade as foundation walls, exterior walls with no additional protection or siding needed and many other situations when something more than OSB is needed.

Magnum Board® products are:

• Virtually impervious to fire – are non-flammable and non-combustible
• Virtually impervious to water – can be fully submerged for long periods of time with no affect dimensionally whatsoever
• Unaffected by all insects – such as termites and carpenter ants
• A non nutrient for mold or mildew
• Are completely non toxic
• Homogenous construction to eliminate delaminating
• Available for almost every application required in construction for of your projects including Residential, Commercial and Industrial.

Earthcore also offers a variety of demising wall options for the multi-family or commercial project.  A choice between a magnesium board skin or a Blazeguard® coating can be made to reach a class A fire rating.

You can learn a lot more about SIPs by visiting Earthcore’s blog.

So first, you need to familiarize yourself with some basics about the way that heat energy moves around. There are really only three ways this can happen:

1) Conduction - this is direct heat transfer through a material. Some materials are better conductors than others. This is why pots and pans are metal and scuba suits are synthetic rubber.

2) Convection - this is literally where a material that has heat in it physically moves to another location. This seems rather low tech, but it is quite effective. Consider where hot air goes and how nice it is to have a summer breeze.

3) Radiation - Without this one, we would be a cold, dead world. The Sun transmits all of it's energy through the solar system via this method and it is a very important mode of heat transfer.

Three Means of Heat Transmission (image courtesy of Williams College)

This discussion is going to focus specifically on Conduction. I'll leave the other two for another post some other day.

So how does conduction work in a building wall (or roof or floor...)? Simple: The temperature on both sides of the wall eventually want to reach equilibrium. So, if it's hot outside and cool inside, the wall itself will allow the heat pass through the wall and warm the inside of the wall until both temperatures are the same (in fact the temperature at any point in the wall is the same). The resistance in the wall to letting this happen is called R-Value. The higher the R-value, the better job the wall does at keeping the heat from passing through the wall.

That's simple right? WRONG!

There's something very important going on here though that nobody ever talks about: The time that it takes for the energy to reach a steady state of flow. Simply put, it takes time for the energy to make it through the wall and that effect is not described at all by r-value alone. Without getting into the ugly equations (which frankly, I no longer have committed to memory anymore), there is a special property of all materials that tell you how well the material can store the heat that is passing through: the specific heat capacity. Combine this with the actual density and thickness of the material, and now you're able to talk intelligibly about how a wall will really react to changing weather. Enter the world of thermal mass.

Consider the image above. The conductive mode of heat transfer is through the steel rod. Given steel's very low thermal resistance, we know that if you hold on to the rod long enough for the heat to reach your hand, you will get burned. HOWEVER, it takes some time for that heat to reach the hand - it is not instantaneous and therefore, R-value does not describe what is going on during this time. If you were holding a brick, it would take significantly longer for that heat to reach steady state and burn your hand.   By a similar demonstration, if it takes more than 12 hours for the outside temperature and the inside temperaturef a solid thermal mass wall to reach equilibrium because the wall itself stored a lot of the energy passing through, then day turned into night and the temperature on the outside of the wall is now different. The energy flow may even reverse and the wall will rarely, if ever reach a steady state of energy flow. So knowing that, we can throw r-value alone out the window as the sole metric for thermal performance except in climates with very uniform day and night temperatures.

Instead, we should be considering materials with a high capacity to store heat and slow down the passage of heat flow to at least 12 hours. Light frame wood and steel stud construction doesn't have much density and steady state is reached much more quickly than solid dense walls. That doesn't mean that light frame construction is inherently bad - it just relies much more on r-value to thermally perform. This is where SIPs construction can be extremely valuable. However, with denser wall materials and capacity to store heat, we can still make the comfort level within a building much less dependant on the outside air temperature. Imagine if you had walls that took days to reach steady state. Then that passing three day storm may never have an effect on the heat loss in through the wall whatsoever. Too bad we have doors and windows, but their thermal performance is another topic for another time.

Strangely, there is very little data out there to corroborate this, except for the fact that the comfort level in masonry and concrete structures (including ICF) and other solid construction wall types like log, adobe and rammed earth is really quite high despite the fact that the conductive r-values are very low. We need more studies on this phenomena to better understand how we can leverage the properties of materials to make new and much higher performing building materials. It is something that could significantly impact the thermal performance of every building we build in the future and can get us that much closer to a carbon-zero footprint.

The Cathedral of Central Texas

The cathedral will continue to be the focus of the site and act as the cornerstone of the new campus.  The objective of the master planning process will be to arrange the supporting buildings and additional facilities in a logical, complimentary fashion while paying close attention to topographical considerations.  Our goal is to design a campus that will maximize the use of the site while having a minimal impact on the existing natural features.

The master plan for the campus will include identifying locations for a 10,000 square foot Lecture Hall, a 25,000 square foot Convention Center, 40,000 square feet of commercial facilities, a 24 unit Multi-Family facility, and a 5-6 acre cemetery with all necessary supporting infrastructure.  New Urbanism planning strategies will greatly influence the design of this project.

The on-site storm water detention requirements for the entire development will be designed to be held in a single pond that will be surrounded with green space and walking trails.  Water from the pond will be re-used for irrigation of adjacent prayer gardens.  Other examples of sustainable site design will be incorporated into the development as opportunities present themselves during the design process.

Upon the final approval of the master site plan, EV Studio will immediately begin the design of the 10,000 square foot Lecture Hall.  This facility will provide the much needed space for the very popular Bible Study courses offered by the Christian House of Prayer.  This will be a state of the art building with amenities paralleling those of nearby colleges and universities.

The EV Studio Civil Engineering Department will work directly with our Planners and Architects to insure the best possible solutions to the numerous challenges that await us on this project.  We will continue to share our experiences on this project through many future posts and articles.

Site Aerial View

Just to admit bias to new readers, EVstudio is an architecture and engineering company, we participate in many projects titled "design-build".

Design-build can be a great setup where you have a company that has experts and licensed professionals working on both the architecture and construction portions of the project. They can typically deliver a project on budget and they may be able to reduce your upfront design fees because they bury them in your total project cost.

Unfortunately, what often happens is that the design-build team is an outgrowth of only one profession. You frequently have a general contractor who has decided that they can do the design work as well. Suddenly you are hiring someone to design your home who is only marginally qualified and yet you are paying enough for the service to hire a full time architect. With this approach you are also hiring someone to design the project who is often most concerned about the simplest details and is likely to give you reasons that you can't have something more complex.

What I would advise all clients entering a design-build setup to do is make sure that you know who is actually doing the designing on the project. You should be meeting with the architect directly and be pleased with the design work that you are receiving. When we participate in design-build we meet with clients directly for the design and the contractor meets directly for the build. They only pay one bill but it is distributed according to the work involved. The architect is your advocate and more able to provide solutions based on years of full time design experience rather than excuses.

Another solution that works well for the client is hiring an architect and a contractor at the same time and working as a team throughout the project. We do this with many of our favorite contractors and it is a rewarding way to bring experienced professionals and still give the client an integrated project. While it is not truly design-build it offers many of the advantages.

There are a large number of project delivery methods in architecture and construction, please ask questions or give us a call.