ICF vs. SIP…The Debate Continues

October 31, 2008

We are working on a LEED Platinum housing project and have been doing a tremendous amount of research on both SIP and ICF construction. For the uninitiated, SIP construction (Structural Insulated Panels) is a construction method where rigid insulation is sandwiched between sheets of OSB sheathing, creating a thermally broken solid wall form. ICF construction (Insulated Concrete Form) is a method where rigid insulation makes up the permanent forms for a poured concrete wall. Both systems are extremely airtight and both are systems that provide thermal breaks in the walls. Very important things for a highly sustainable design.

Our findings so far:

In order to get the full points for LEED credit, we need to either have a mass wall (ICF) with an actual (not performance) R-value of at least R-14. This is easily done with just about any thickness of ICF wall because the foam insulation is where the value is really calculated. You get actual R-17 to R-22 depending on the ICF block – “equivalent” r-values are touted in the 40’s and 50’s, but that includes the thermal mass equivalency and is really an apples-to-bananas comparison anyway, so don’t believe everything you hear.

For SIPs, we wouldn’t consider that a mass wall, so the actual R-value needs to be a minimum of R-21. Again, easy to do in a 6-1/2” SIP panel (which would be R-42 – way over everything else by comparison). If we have poured concrete floors inside the building, then we have plenty of thermal mass inside the home (where we really want it), and not separated by a layer of insulation (which is one of the complaints with ICF).

Both systems are thermally broken systems as far as LEED is concerned. Both systems will be very high performance for airtightness (and will require an HRV). It appears that only SIPs will allow us additional LEED points for pre-built panel assemblies since ICFs are site-built assemblies that are then poured on site. We’re still researching that with LEED though, so I will validate that and amend this post when we have more data on that.

Space is also a fairly large consideration as well. LEED calculates the area from the outside face of the rough assembly, so the additional thickness required by ICFs will add approximately 120-150 sq.ft. of wall thickness for a 2,000 sq.ft. footprint. I know that sounds crazy, but there is quite a bit of square footage tied up in our exterior walls that isn’t useable, and the thicker the walls, the more that hurts our ability to keep the space functional and stay within the LEED guidelines that won’t require us to add additional points to our requirements total. So, to maximize LEED points, it’s not enough for a wall to perform thermally, it also needs to do it with minimum wall thickness – now we really are talking the 21st century modern home here!

Chances are, any sustainably built low-rise Type V building project will have both ICF and SIP components, it really is a question of “how much ICF and how much SIP”. Right now, unless there is some major economic advantage in the initial cost for using ICFs, the information I have is telling me to build the foundation with ICF and use ICF for walkout basement conditions if site topography warrants it. Then run the SIPs from the main level floor up.

This will also allow you to handle common details more easily. For example, you can set the foundation wall to the inside face of the sip so that it can act as a ledge for stone or brick veneer while preserving the thermal break. It’s also worth noting that angles other than 90 degrees at the building corners are easily done with SIPs and won’t pose any problems with designs that are customized. In fact, just about any shape is possible with SIPs – even curved forms. You can do those angles with ICF as well, but it isn’t a lot of fun, so you want to minimize those kinds of design features wherever possible.

It’s also worth noting that there are a lot of good reasons to plan for SIP walls running through the building, separating key areas as they provide great thermal separation and sound attenuation in the same space as a conventional stud wall.

We actually started this project thinking that we would need to go to ICFs in order to maximize our LEED point potential, however, it turns out that SIPs actually have a slight advantage when it comes to LEED because of their reduced thickness. For all intensive purposes, they will perform equally in a LEED thermal analysis though, so unless you can build an ICF wall for less than a SIP wall, the SIP wall would be the best choice.

If you are looking to have a highly sustainable building designed, this information is only one very small part of the comprehensive analysis for the great number and variety of design decisions, and all of these choices must be tailored to your specific situation, location and site adaptation. With that said, we strongly urge you to engage the services of a design professional that has the knowledge and experience so that the financial investment in your building is validated and actually performs. In fact, in order to get LEED certification, you are required to assemble a design team that has those qualifications. Contact EVstudio if you have any questions or need to discuss your next sustainable project.

For more SIP info read my post Top 10 Important Things to Know About SIPs

State of Colorado Architect Registration – Education and Experience Criteria

October 31, 2008

Colorado is a fairly unique state for Architectural Registration. The vast majority of states now require that applicants for licensure have a NAAB Accredited Professional degree for initial licensure. The two options are the Bachelor of Architecture and the Master of Architecture degrees. Colorado does not require that you have one of these degrees if you have enough experience. In fact, you can become licensed in Colorado without any college degree at all if you have 2,350 days of experience.

For more information click on the chart above. It is pulled from the Bylaws, Rules and Policies of the State Board of Licensure for Architects, Professional Engineers and Professional Land Surveyors.

There are definitely still advantages to the B.Arch and M.Arch routes. I have a NAAB Accredited Master of Architecture degree which makes it possible for me to register in any state and the provinces of Canada.

EVstudio is Upgrading to AutoCAD Architecture 2009 and Revit Architecture 2009 – Why Support Both?

October 30, 2008

EVstudio is upgrading to the latest versions of AutoCAD Architecture and Revit Architecture. We currently use a previous version of AutoCAD on the majority of our projects and Revit on select projects.

There is a lot of debate on the advantages of one software program vs the other. At this point it seems that neither product is the right solution 100% of the time so we’re supporting both and carefully choosing which gets used for what. There is cost associated with this approach but it is the only approach that insures the quality product that we create. We won’t let the software dictate the design or the documentation.

Revit is a software package that originated as a competitor for AutoCAD but ended up being bought out by Autodesk to compliment their products. To design a building in Revit you actually build a model of the building and then represent that model in different views rather than drawing the views themselves. Revit has a lot of advantages in visualization, for creating a building information model and drawing management. Most likely, Revit will be the dominant software at some point in the future. It is exceptionally effective and quick for putting together many building types. Where it is lacking is in the drafting tools, complex residential building shapes and the visual representations of the model. When it comes time to document a building, Revit does not produce as nice a set of drawings. With EVstudio’s commitment to drawing quality we can’t fully commit to Revit.

AutoCAD Architecture (which used to be called Architectural Desktop) is a version of the venerable AutoCAD that I first learned in 1991. It is a 2D drafting program that has been enhanced to include many of the features of a full fledged building information modeler. While Architecture is not the easiest or best tool for any one task, it can be customized and utilized to produce a drawing set without compromises. We’ve built a complex graphical menu system, many custom routines and even a set of structural routines for calculating the residential structures that we design. The software has been set up to create a quality set of drawings and I expect that it will be a part of our workflow until Revit catches up on drafting tools and modeling options.

There are a number of other factors that go into the decision of choosing Architecture vs Revit on a project. Most architects and interns know AutoCAD and only a handful know Revit so staffing and support is harder. AutoCAD allows a floor plan to be developed without the elevations and sections where Revit makes you do them all at once. A very different workflow, both with advantages. Many of the large clients who we work with like Aardex and the University of Denver have large libraries of AutoCAD drawings to use as a starting point on projects. This is also true on many of the tenant improvement jobs that we do where we may receive CAD backgrounds. Some engineers want to work in Revit, some only work in AutoCAD.

I hope that further explains why EVstudio is upgrading and maintaining licenses for both Revit 2009 and AutoCAD Architecture 2009. It will be interesting to see what new features are in both.

EVstudio has Begun Work on a Firm Monograph

October 29, 2008

We’ve begun to put together a monograph book for EVstudio showing a collection of our architecture, planning and design work and telling a story about the firm and each of the projects in the book.

I’ve noticed that only a few firms put together monographs and they typically pull only a handful of projects for publication. Our philosophy is a little different where we look at each project as an opportunity for bringing our talents to the design. We are proud of each project and the solutions that we arrived at in the design process. We also believe that each building design deserves the level of attention that we give it.

If you are a current or past client of EVstudio, we’d like to talk to you about gaining additional images and information on your project for inclusion in the book. We plan to publish it within the next few months and then update it annually to reflect the new design work. Obviously it will be easier to document the work that we’ve done near the offices in Denver and Evergreen, but we’re also very interested in other Colorado and out of state work.

Define Green Architecture? What Makes a Building Sustainable and Green?

October 28, 2008

Terms like ‘Green’, ‘Sustainability’ and ‘LEED’ are being thrown around lately and architects have been a big part of the throwing. In fact, at EVstudio have been discussing these terms a lot lately. So what do these terms really mean and what do they really have to do with architecture?

The word ‘Green’, as it applies to the interests of the environment, has been applied to everything from household cleansers to SUV’s to buildings over the past few years. At the same time, the terms ‘Green’ and ‘Sustainable’ have come to be somewhat synonymous when referring to design. So what do they mean? According to the General Services Administration, who overlooks all Federal building projects, green or sustainable design is defined as design that seeks to “reduce consumption of non-renewable resources, minimize waste, and create healthy, productive environments.” In addition, other common definitions expand that definition to include economic, social & ecological sustainability concerns.

So what does this have to do with architecture, then? Tons! According to the Environmental Protection Agency, there are more than 170,000 commercial buildings and more than 1.8 million residential buildings constructed every year. In addition, more than 44,000 commercial buildings are demolished annually. They did not include a statistic for the number of residential buildings demolished on an annual basis, but considering the number for commercial buildings, it is probably quite substantial. Furthermore, the study states that buildings consume more than 40% of the total raw materials globally. In the United States alone, buildings account for 39% of the annual primary energy usage and 70% of the electricity usage. The same buildings produce 39% of the total CO2 emissions (more than ALL the cars on the road!) and create more than 136 million tons of construction and demolition waste that goes into landfills and incinerators every year. Residential buildings alone account for more than half of these numbers. These statistics, however, deal only with the environmental impacts of the built environment. Economically the construction industry accounts for approximately 14% of the Gross Domestic Product (GDP) in the US and somewhere between 8% – 10% of the GDP globally. The current state of the US and global economy testifies to the validity of those numbers. Finally, to bring it down to the personal level, Americans spend 90% of their time indoors on average and the indoor environment can contain up to 200% more pollutants than the outdoors, depending on the age and type of construction.

Here at EVstudio, we believe that sustainable design is design that carefully and effectively balances all of the unique characteristics of a project including the economics, environmental issues, site opportunities and constraints, functionality and marketability into the collective ‘vision’ for the project. A project is not sustainable if it is neither affordable nor suits the specific needs of the client. With this in mind, however, we have built many of the most effective sustainable design strategies into our everyday practice. These strategies include concepts such as passive solar design, natural daylighting, and natural ventilation which take advantage of the opportunities inherent within the site. We consider these strategies and others as merely the elements of smart design that can add real value to the project. These strategies of smart design require only forethought, not additional cost. We feel a great responsibility to create the best designs possible and this includes creating built environments that are an asset, not a detriment, to the life within and around them.

The Easiest Place to Find Fire Rated Assemblies is the Gypsum Association Manual

October 27, 2008

After several projects of fighting with the UL Manual (Underwriters Laboratories) and the International Building Code I discovered that there is a much easier visual way to find fire rated assemblies.

I use the Gypsum Association Fire Resistance Design Manual. Everything is visual and it is generally acceptable to building departments. It contains the most used gypsum fire rated designs and it also contains information on sound ratings for most of the assemblies. Plus it is a free download which the others are not.

The main note is that you need to read the ratings carefully where some of them are proprietary and designed for one manufacturer’s gypsum product. In many cases there will be another number for the same assembly from a different manufacturer or a generic product. You can list them as alternates.

In addition you should read the general notes at the front, they tell you about ways that you can modify the assemblies and still maintain something acceptable for the rating. This is important for adding insulation, adding other layers to the assembly or changing the size of framing members.

Finally, if you need a rating that doesn’t involve gypsum board then your best bet is probably Chapter 7 of the IBC. That’s where I go for concrete and other assembly materials.

EVstudio Architecture is Now on Facebook

October 26, 2008

EVstudio now has a fan page on facebook.

Please check it out and consider becoming a facebook fan of EVstudio.