Tuesday, March 29, 2011

Insulated Concrete Forms or ICFs

Insulated Concrete Forms or ICFs are a modern building material with specific traits that most homeowners would find desirable. These include high energy efficiency, very low air infiltration, high sound deadening and a significantly stronger structure. Of course, all these benefits do come at a higher cost.

ICFs are typically made in the form of blocks. Each block has a foam panel on each side with a space in between. The space can be 4”, 6”, 8” or more. These foam blocks are stacked up to form a wall. As the wall is stacked, steel reinforcing rod is placed in the space between the foam panels on a grid pattern. Once the wall is erected, concrete is poured into the space. The ICF becomes a composite material of foam and concrete. The concrete provides the structural component of the wall and the foam provides the insulation component.

Once the concrete cures, interior walls are built with wood or steel and a conventional roof is placed on the home. On the exterior, any conventional siding material can be applied directly to the exterior of the ICF block. Same thing on the inside, drywall is applied directly to the surface of the ICF block. Once completed, the home looks like any other home, however it is stronger, quieter and more energy efficient than most others.

Building your home with ICFs will typically add about 7% to 10% to the total cost when compared to standard 2x4 construction. The difference is less when compared to more energy efficient wood framed homes. Standard ICFs are ideal for areas with severe weather such as tornados or hurricanes. As far as energy efficiency, standard ICFs are best for areas with hot to moderate weather. There are special ICFs with thicker foam on the exterior surface that are better for colder climates. There are a number of different ICF manufacturers, each with their own unique product. When choosing an ICF, while it is very important to pick a high quality product, it is just as important to pick a product with good dealer support. Also be sure to select a contractor with good experience in ICF construction.

While ICFs will never be used to build every home, there are certain situations where they are the best choice. And because of some specific qualities, once you have lived in an ICF home, you will probably never want to live in anything else. If you wish to learn more about ICFs as well as see pictures of homes during construction, please visit my website, www.clemdesign.com/Logix.html  I am a distributor for LOGIX ICFs. On their website, you can find lots of information including engineering specs as well as videos. The URL for LOGIX is http://www.logixicf.com/

Thursday, March 24, 2011

New Design Added, JC-91

I have finally made a new stock plan available on the ClemDesign web site. The JC-91 plan is a modern style ranch home with open living and lots of windows. Currently, there are two roof options, a butterfly configuration and a low gable configuration. The home has 2 bedrooms, 1 ¾ baths, a laundry/mud room and a 2 car-carport. Of course there is a large, open living, dining and kitchen area. The kitchen is quite large with a center island and a pantry.

Here is a link to the JC-91 design page:  http://www.clemdesign.com/designs/jc-91/.  This design utilizes modified 2x6 walls on a crawlspace with a conventionally framed roof supported by large glulam beams. The windows shown may need to be altered depending on the climate and orientation of the building site.

I plan to add a third roof option in the next few days. This will be a flat roof with ample soffits and a raised center section with clerestory windows.


More on Building Costs

Here are some construction cost numbers that can be found on the energetech web site. They also provide detail as to how these numbers were generated. I do think the cost of the 2x6 walls could be lower and the R-value higher if they used 24” centers.

Wall Construction                                     R-Value                 Cost/S.F.                 Cost/R-value/SF

Standard 2x6 @ 16" O.C.                          13.70                      3.72                         0.27
2x6 @ 16" O.C., 2" XPS                             25.00                      6.56                         0.26
2x8 staggered stud, 1.5" XPS                    30.00                      6.45                         0.22
Double 2x4 wall, 12" total thickness          36.50                      6.96                         0.19

By searching the web, I came across some SIPs numbers that appear to be an average, but no sure how accurate they really are.

6.5” SIP w/5.5” EPS                                 21.00                     6.50                          0.31

This is with $4.25 per sq ft for material and $2.25 per sq ft for installation of SIP panels. I am assuming the $4.25 price is for SIPs is ready to install including all window and door cutouts. Also, the $2.25 per sq ft cost for installation seems a little high, but I did find similar numbers on several web sites.

It does seem that SIPs appear to be the higher cost in relation to R-value per sq ft.

One item that is not taken into account with these numbers is air infiltration. With proper installation, the SIPs walls should have a lower rate of air infiltration than the stick framed options. But the higher cost stick framed options should have very low air infiltration rates compared to standard construction.

So I am not sure there is a good answer in the information here. While most of the stick framed walls have higher R-values, they will probably suffer slightly higher air infiltration. And though the SIPs wall has a lower R-value, it would typically be considered a structurally stronger wall than the other options. If I find more or better information on this subject, I will post it.

Sunday, March 20, 2011

Building costs, stick framing vs. panel construction?

The most common form of residential construction in the US is stick framing. This is a tried and true technology that has been in use for over 100 years. It is so widely used because it is fairly efficient from the stand point of material usage, material cost and construction speed.

But, stick framing is not perfect. It may be an efficient way to build walls, but it suffers from a couple of deficiencies. Because a wall is constructed of many, many parts, it can have excessive air infiltration reducing energy efficiency. Another issue is thermal bridging. Because the studs span from the interior surface of the wall to the exterior surface, thermal energy is transmitted with less resistance through the studs than through adjacent insulation reducing energy efficiency. And lastly, because a standard wall is made from 2x4 dimensional lumber, there is simply not space to add enough insulation to attain high enough thermal resistance. All these factors added together produce a wall that is not particularly energy efficient.

In order to try and improve the energy efficiency of stick framed structures, we are now going to extreme measures. These include increasing the thickness of walls to 6”, 8” or more. Another option is to build two walls adjacent to one another with space between, increasing the space for insulation. We also add various types of foam sheathing to the exterior surface to increase the insulation value of the wall and reduce thermal bridging. Some people also add wood strapping to the interior surface to allow additional space for insulation. All of these measures do increase the energy efficiency of a stick-framed wall, but they also increase the cost by adding additional materials and increasing the labor required. Since labor is such a large part of the cost of a building, any additions that increase labor are particularly problematic.

There are other building materials that have energy efficiency advantages over stick framing. SIPs and ICFs are the two most common. Both of these materials are more energy efficient and both cost more than standard stick framing. The question is, where is the break point when modified stick framing costs as much as other, more energy efficient materials? ICFs are concrete filled foam forms. While ICFs are much stronger than other building materials, they are very different than traditional framing. SIPs on the other hand are a panelized wall system and are in some ways similar to traditional framing.

So for this discussion, I am specifically interested in a cost comparison between SIPs and stick framing of a structure with comparable whole wall R-values. At this point, I do not know of any non-biased studies to reference. But, I am going to research the question. I hope to be able to post some additional information regarding this subject in the near future.

Wednesday, March 16, 2011

Building a Modern House on a Budget

Can a Modern Home be built on a reasonable budget? And I guess by reasonable, I am saying within the means of most of us or for less than $300 per square foot! There is great variability in what it costs to build the average home in the US. Here in the Kansas City area, an average house costs about $120/sq ft. Depending on where you intend to build, your costs may be higher or lower. By average, I mean a home with nice finishes inside and out, not the real low-end cheap stuff, but not the very high-end options either.

A better question might be; What is the cost to build a modern home in my area? And I think the answer to this question relates to your goals and your budget. Building on a budget is the same everywhere. There are strategies you can implement to help reduce your overall building costs. For specifics, see my blog from March 9th. Beyond this, how can you achieve the modern house you want at a reasonable cost? And to be specific, I am speaking of a modern home similar to many of the MCM homes built in the 50s and 60s, not a modern mansion like you see in some magazines. Whether you build a ranch, a split level or a cube shaped home, the majority of the materials utilized are the same as with most other homes.

If we look at the differences between your friend’s traditional house and the modern home you want to build, you will see that the structure of both appears to be much the same. They all have some sort of a foundation and some variation of four walls and a roof. On a modern style home, one of the biggest differences has to do with the roof. Standard house roofs are typically built with trusses, which are fast and therefore cheaper. And most of these roofs have a medium to steep pitch, which allows the use of less expensive roofing materials (relatively). The roof on a modern style home may either be flat or have a shallow pitch. In either case, they are typically stick framed which takes more time and materials, increasing the cost. And they require more expensive roofing materials. So, a modern house roof costs more in comparison. How much more depends on the size of the home and the complexity of the roof, but for the sake of argument, lets say the roof costs an additional $25K.

Another major difference between your friend’s house and a modern house will be the windows. The modern house will typically have more/larger windows. This adds to the total cost. The cost increase is very dependent on the quantity, quality and the type of windows. By shopping around, you can typically find good quality windows at a price you can live with. Maybe the cost increase will be $5K or maybe a little more. The more windows you add, the higher your relative cost.

Exterior siding materials cost the same on either style home whether it be cement siding, wood siding, stucco or brick; no vinyl siding please! And the interior finishes have much the same cost too. Whether you use carpet, wood flooring or tile, these all can cost the same, depending on your choices. Appliances and fixtures too cost the much the same in a modern house. You will probably have to shop around to find what you want at a good price, but that is the same with everything. A modern style house uses many of the same materials as any other house, it’s just the finishes, textures and colors that make them look different.

Be aware that you can really blow your budget if you buy only $400 faucets, select tile that is $30/sq ft, cannot settle for anything less than a $6K refrigerator or spend $35K on your kitchen cabinets. To stay within your budget, you have to make realistic choices and some compromises. Keep in mind that just because something costs 5 times more, does not necessarily mean it is 5 times better. Plus, you can always upgrade interior finishes and fixtures in the future when you have more money.

One place you can save money with your modern home is by eliminating interior trim. Instead of trim, you can drywall wrap your windows and doors. There are all sorts of cool plastic drywall accessories that allow drywall to be terminated with a clean, sharp edge. With these, you can also eliminate all your base trim. Since trim is expensive to purchase and install, eliminating it can save you a few thousand dollars.

If we look at the cost of building a traditional 2000 sq ft home on a slab foundation at $125/sq ft, we get a total of $250,000. If we add the extra for the roof and the windows of a modern home, we get $280,000 or $140/sq ft. These are rough cost estimates and are only an example, but they illustrate the cost difference between your modern home and your friend’s traditional home could be as little as $15/sq ft. You have to decide if the extra money is worth spending to get what you really want. I realize that not everyone will be able to achieve this, but it can be done with a little work on your part.

You can find a similar article with a little more information on our Green Building page here: http://www.clemdesign.com/InfoPages/BudgetMod.htm.

Monday, March 14, 2011

Modern ICF house design

We recently received a picture of one of our projects under construction in Vancouver, BC. It is a modern style house being constructed with LOGIX ICFs (insulated concrete forms).

This modern home was designed with the main residence on the upper floor with a rental apartment below. This home utilizes ICFs for the exterior walls and conventional framing for the interior walls and roof. The large center shed roof is carried by 3 large, exposed glulam beams. The main living area beneath the shed roof is large and open with windows on the south side to bring in ample light. The main living area opens onto a large, partially cover deck. One unique feature of this design is how the glulam beams are carried well beyond the south exterior wall over the deck to provide shading as well as a sheltered area.

ICFs offer several advantages over other building materials. These advantages include high energy efficiency, high sound absorption, very low air infiltration and a structure that is stronger than can be achieved with lesser building materials. To learn more about ICFs, you can visit the LOGIX home page at http://www.logixicf.com/

You can learn more about this home by visiting the Samson project page here, http://www.clemdesign.com/ProjectPages/Samson/Samsonproject.htm  You can see some of our other current projects by visiting our projects page here, http://www.clemdesign.com/ProjectPages/Projects.html  We hope to have more pictures of the Samson project soon.

Saturday, March 12, 2011

Green Building Talk

Another web site I highly recommend is www.greenbuildingtalk.com. This site offers a wealth of information provided by a number of professionals actively involved in the construction industry. There are sections of the forum pertaining to: Residential Construction, Commercial Construction, Green/Energy Efficient Design and Planning, Green/Energy Efficient Building and Construction, Insulated Concrete Forms, Structural Insulated Panels, and several other categories.

On this site you can create a login and ask questions on any related subject. Chances are you will get some very well informed and creative answers. Whether you are seeking an answer to a general question or need information on something very specific, you may very well find your answer here. You may also gain a lot of useful information simply by perusing the various topics every week or two.

Wednesday, March 9, 2011

Home Building on a Budget

It seems that the cost to build a new home is much too high. Not everyone wants to spend $300K or more. Some people want a nice, medium sized home with some style for a more reasonable cost, maybe $150K or so. This would be a Midwestern cost, building on either coast will be more.

Regardless of where you build, there are a number of things you can do to reduce your building costs. Below is a list that I have put together:

1. Plan to save – As you develop plans and the design for your home, it is a good idea to start assembling initial estimates. Although these may not be quite accurate at this time, they can help you with making choices for the structure and finishes to be used and to help you understand what your total costs will be.

2. Build small – Every square foot of the home costs money. By reducing the footprint of the home, you will reduce your overall cost. You want the floorplan to be as efficient as possible but still have the spaces you truly need. Eliminate rarely used spaces such as a formal dining room and consider how rooms can serve double duty such as a home office can also be the guest room with a murphy bed.

3. Squares and rectangles – The cheapest form to build will typically be some variation of a square or a rectangle. Most other building shapes are more complicated to build will increase the cost.

4. Build up – Depending on the footprint of the home, it will typically be more economical to build up rather than out. Building up reduces the size of the foundation and the roof, reducing your overall costs.

5. Build for quality – As with any home, it is important not to skimp on the structure in order to save a few dollars. Use 2x6 framing on 24” centers. This costs the same as more typical 2x4 construction, but allows for more insulation. Also use quality exterior finish materials that will last for many years.

6. Build for energy efficiency – Making a new home more energy efficient costs very little up front but will save you money every time you pay the utility bill. Amortizing $1000 into your loan for energy improvements will typically cost you less each month than the money you save on utilities.

7. Consider alternative materials – Alternative materials include recycled and re-purposed products as well as using materials for uses other than originally designed. All of these can reduce your material costs.

8. Postpone frills – Actually, this should be postpone or eliminate the frills. For some things you can substitute for less expensive materials today, and upgrade at a later date. Other things can be eliminated entirely such as interior trim. If you are building a modern home, what is more modern than the clean look of no trim? Drywall returns at window and doors is an inexpensive way to eliminate trim.

9. Save in the kitchen – Traditional kitchen cabinets can be very expensive. $20K or more for cabinets is not uncommon. Consider alternatives such as a recycled stainless commercial counter/sink, homemade concrete counter tops, or possibly wire shelving racks for storage. Yet another option is cabinets that need assembly such as those from Ikea.

10. Sweat equity – Labor costs today are very expensive. Everything you can do yourself during the construction of your home can save hundreds or thousands of dollars. Painting is a great example. The average home costs several thousand dollars to be painted by a professional while the materials cost only a few hundred. So, the more of your time you can invest in the construction, the more you will save.

I am sure there are other ways you can save money on the construction of you home, but the list above might give you a good start. With good planning, hard work and a reasonable budget, you too can make your dream a reality.

Friday, March 4, 2011

Modern Home Options, Build New, Rehabilitate or Remodel

You want a modern house but you quickly learn that your desire may be difficult to fulfill. If you want a modernist home, you are basically faced with three options; build new, rehabilitate an older modern home, or take an existing home and extensively remodel it to modern style.

The first and the most straightforward is to build a new modern home. For this option, you need a lot on which you can build, plans, a builder and financing. Seems simple enough, but it isn’t. The first problem may be the lot. In most municipalities, building lots are primarily controlled by developers. And typically, developers don’t want your modern house next to their standard offerings for a number of reasons. Your other choices may be an in-fill lot in an existing neighborhood, or find a lot with no restrictions or build in the country. All of these options may be valid; they may just take more effort on your part to locate. Plans are pretty easy to come by these days, either from a website such as http://www.clemdesign.com/  (yes, this is a shameless link to my own site) or have them created by a local professional. Builders are readily available too. But, finding a builder who won’t get in your pocket because you are building something a little different is another matter. Builders need to ensure they make a profit and are thus skittish about unusual buildings. So, they may increase their bid to account for the unknown. One way to reduce this problem is to find a builder who will work on a cost-plus basis in which they get an agreed upon profit margin for their services. This is typically a percentage of the total building cost. The last issue is financing. This too is pretty straightforward, it just may take a little work on your part to find a bank that is comfortable financing a modern home. Building new may be the easiest, but it may be the most costly of the three options.

The second option is to rehabilitate an existing modern home. I say rehabilitate rather than remodel because you are bringing the home back to life, not necessarily changing it. There are typically not a large number of older modern homes available on the market, but they do exist and they do come up for sale. 10 years ago, most of these could probably be purchased at a great price. But, with the resurgence in popularity of modern, prices have increased considerably. Beyond the purchase price, you have to consider what it will take to rehabilitate an older home to the condition you want. Like with most rehabilitations, you may have the pleasure of replacing any number of things, roofing, siding, flooring, cabinets, interior finishes, plumbing, electrical, insulation, etc. etc. etc…….. It can be fun, frustrating, maddening, and expensive, but it can be done successfully. As a bonus, many older modern homes have a unique feeling or atmosphere that is very difficult to reproduce in a new build.

The last option could be to buy a nice ranch in a nice area at a nice price and remodel it into a modernist style home. With this option, you would be making dramatic changes to the structure, style and finishes of the home. This too can be can be great fun along with great frustration and nearly limitless options. In order to improve the finished product, you might want to consult with a design professional. A benefit with this option is that it offers an opportunity to get what you want for possibly the least cost compared to the other two options. But, it is not an option for the timid or faint of heart.

So, being mindful of your choices and the pros and cons associated with each, go out and find or build the modern home you really want. Don’t settle for anything less, because you will never be as happy!