Gravitas Blog

We recently had the pleasure of visiting one of our smaller structures as it is going through its final steps before completion.  Derek Hurd of Gravitas worked with a couple from Texas that were permanently relocating to Boise, Idaho.  They asked Derek to design for them a small accessory dwelling unit (ADU), behind the home they had owned for a few years, but rented out.  They had decided to move permanently to Boise, and the small building would serve as a writing loft for the couple.  They gave Derek a little direction to go by asking him to be inspired by Japanese Tea houses.  The couple referred to the ADU as the “Writing Shed”.  At Gravitas, we called it a “Zen-in-Law”.  Either way, it got the point across, a small out-building, dedicated to the more contemplative things.

The owners came across our company through a mutual friend.  We’re always appreciative when past clients, and future friends can pass along our name to those in need of thoughtful design.  After the owners diligently investigated us, and our web presence, they called, and discussed their needs with Derek.  What ensued was the typical package of sketches being sent, and descriptions of likes, and dislikes.  Derek then integrated all of the ideas, and came up with a  contemporary little writing studio.

We are only a few days away from the final punch list, and we hope to get photographs of the finished work in a few weeks.  Good timing to enjoy the cool Boise evenings.  I’ll be sure to include them in a future post.

Here we can see the little house in all of its glory.  One of Derek’s soft spots is for the faithful ‘butterfly roof’.  It’s simplicity in design ins contrasted with its complexity of construction.  We were treated to some interesting stories of its construction by the crew from Green Remodeling, who did a terrific job helping to realize the owner’s dreams, and Derek’s vision.  One of the wonderful things about this sort of roof, is the fact that all of the wall studs, and all of the roof rafters are unique in length.  This, in addition to the compound angle makes a standard out of the box approach to construction unsuccessful.  Thankfully, Kenji Wright, John King, and Josh Bogle were able to accommodate the design, and deal with the mathematics of the framing.

As with any remodel, or addition, staging the construction of the project can present some challenges.  The site is located at the back of the lot, perched 30 feet above the road.  Luckily there was a vacant lot behind the building (behind the fencing we see to the right).  Through this lot, they were able to bring in the concrete for the foundation, and the floor, as well as the other building materials.  Utilities had to be trenched out to the front of the house.

Siding is T-111 no groove panel, with 1×2” cedar battens at 16” on center.  All earth tones on the finishes help to reinforce the timber feeling, and blend in with the surrounding landscape.  One of the not so surprising ramifications of a ‘butterfly roof’ is the tremendous water collection that it affords.  In this case, the runoff is channeled to a small spillway, that deflects the force of the water as it hits the ground.  The rain is then allowed to gently seep into the soil.  That’s the theory at least.  I’ll check in next spring, and see how things are going.

A fish-eye perspective of Kenji finishing taping before the final finish is put on the loft floor.  The open loft looks down into the common area, with a kitchenette, and writing bench below the window.

Family friend “Woody” stands at the ready to greet any new arrivals.   The owners’ other pooch, a Corgi, is behind the scenes, making sure that everything is built according to plan.  The deck makes a nice perch to view the rest of the yard, and the use of canted beams eliminates the columns breaking up the natural flow, and the site lines.

The landscape walls are made of lava rock, and they turned an aggressively sloping back yard into a series of terraces.  This created much more usable space for the family to enjoy the Boise summers on, and it helps mitigate the runoff, allowing it to soak into the soil, and not run unhindered towards the house, and deck below.  Again, this will be interesting to revisit, after the owner has had an opportunity to enjoy the home for a season or two.

The Laramie

We could tell that this was a special little home from the beginning.  We’ve adopted it into our “Plan of the Month” series that we offer.  We have renamed it to protect the innocent to the “Laramie”.  We haven’t updated our plans list on the site yet, but if you are interested, here is a link to the plan information. We are currently working on the animation for the building, so check back with us next week, and it should be wrapped up.

–Click on the image to download additional content–

I think Derek did an outstanding job on this little home.  It provides the owners with a little get-away retreat, as well as a working office to write from.  It has a sleeping loft, kitchen, full bath, and an area to stretch out in.  There is not much more you can ask for.

Mark Wagner<>Gravitas

The following is from a newsletter from our engineer Brian Sielaff of Tamarack Grove Engineering. Brian has been engineering our projects since the beginning and specializes in structural engineering for residential projects as well as engineering for log and timber frame homes.  Enjoy:

The common goal on any log home/timber frame design and construction is to have a client’s experience that is built on trust and understanding. From the very beginning, there are a lot of decisions that need to be made with building a structure. Often referred to as the ‘process’, one must decide on several key items such as budgets, the style of the home, floor plan layouts, total square footages, which manufacturing company to use and then finally who the general building contractor will be. One often overlooked decision in this process is the need for structural engineering design and review.

Structural engineering of your log home/timber frame structure ensures that all building elements of your final construction permit documents are:

1) Well coordinated

2) Have been properly sized for all structural components such as roof framing members (girders, joists, outriggers, ridge beams), floor framing members (girders, joists, ledgers), headers, decks, columns, foundations and retaining walls

3) Ensures that all connections and details are adequately designed using the correct building codes, loads and load paths, and

4) Verifies the building lateral loads (out-of-plane wind or earthquake loads) have been taken into account and are properly resisted.

Often the question is asked, “When is structural engineering required for my log home/timber frame structure?” Based upon where you are building your structure, some of the local building departments and/or local governing jurisdictions will require some form of professional structural engineering construction documents and calculations that are to be stamped and signed by a licensed professional engineer. These documents would include your foundation plan, floor framing plans, roof framing plan, building sections, structural details, general structural notes and structural engineering calculations. Several factors that would require or cause recommendation for structural engineering include, but are not limited to:

1) You are building within a high snow load area

2) You are located within a high wind or earthquake zone

CA FL

3) The complexity of your final floor plans and building elevations (i.e. how each floor level stacks up, is there a prow, are there a lot of exterior windows or opening placements, the column/post spacings, beam/girder spans, is there a daylight basement, etc.)

4) The local governing building jurisdiction requires sealed and signed drawings and engineering for issuance of building permits?

REQUIRED FOR ISSUANCE OF PERMIT

5) The defining site requirements in which you are building your log home/timber frame structure on (i.e. is the building pad site flat or sloped, are you building into a hillside or next to water and what are the native soil bearing types that would dictate the foundation design).

6) How complex the building connections, framing layouts and required detailing are? Do you rely on the general contractor to ‘figure it out’ in the field or do you provide a well coordinated, detailed set of construction documents?

7) How experienced is the designer, drafter or architect in sizing correctly all aspects of the structural framing components to resist all vertical/gravity and lateral load transfer?

A structural engineer can also work with your local jurisdiction to help streamline the ‘process’ and obtain your building permit in a timely fashion, this then allows you, your log home/timber frame company and your general building contractor to begin work. A structural engineer can also be available through the construction process to help answer or clarify any questions that can arise from the construction phase.

Whether it is required or not, it is highly recommended to consult with a licensed professional structural engineer on any log home/timber frame structure that you are building. The common goal for any structural engineer is to safeguard life, health, property and public welfare through the design and implementation process. When put into perspective with what typical structural engineering fees are in relation to the overall cost of your project, you will find that these fees are typically less than 1% of your overall construction budget. For the quality assurance that you are given knowing your structure is designed and coordinated properly by a structural engineer, it provides the additional assurance for your insurance in protecting your life long investment.

-Brian J. Sielaff, P.E., Managing Member, Tamarack Grove Engineering, PLLC

Specializing in Structural Engineering

(Please feel free to contact our office for any questions or comments that you might have related to this article, we can be reached at the following information noted below.)

3170 Overland Rd., Ste. B

Boise, ID 83705

208.345.8941 PHONE, 208.345.8946 FAX, 208.871.0616 MOBILE

brian.sielaff@tamarackgrove.com EMAIL

www.tamarackgrove.com WEBSITE

In our relentless pursuit for the best (relative) green (relative) options for specifications in our home designs I was tracking down more info on soy based spray foam for a home we are designing for the North End in Boise, Idaho. There are as many “best” ways to super insulate a house as there are builders. What follows is an informative article that I found in my search by John Wagner that was published in Residential Design & Build magazine. John is a regular contributor to many industry magazines and a national speaker. You can learn more about him on his site John Wagner.   Below is the article which does a good job of explaining the difference between open cell and closed cell and the applications for both.

By John Wagner

When I was a working contractor, I remember how daunting it was to walk into a large project, bare studs for walls, knowing that I had to work (with a crew of course) to stuff each bay with fiberglass batts. I remember thinking — like a boy wishing he could fly — if we could only liquefy the insulation and spray it in place the job would go much faster. It would also get the insulation into every nook and cranny and save me from using duct tape in an attempt to remove the itchy glass from my arms and neck.

That was in the 1970s, and little did I know that by the time I got out of the blue collar side of building, just such a thing would be invented in the form of spray foam. I mean, let’s face it, you couldn’t design a better dream product. The stuff flows on as a liquid, fills up every crack and what’s best, teams of guys in white jumpsuits apply it in one day’s time. Heaven.

It’s also very green. The problems with propellants have been largely worked out, and there now are water- and soy-based products as well as isocyanate-free, formaldehyde-free alternatives to suit the greenest customer. Once in place it doesn’t leak or off-gas harmful emissions, and all foams are good at reducing noise transfer and sound penetration. What’s not to like?

Here’s how you differentiate among the two different types of foam, and the attributes for each product category.

OC-SPF. Open-cell spray polyurethane foam cures in place, stays soft and is designed to slow convection (the transfer of heat through the movement of warm matter like air) by leaving irregular bubbles that fill with trapped, ambient air. Weighing in at 0.5 lb. per cu. ft. and scoring around R-3.5 per in., the foam tends to have an R-value close to captured, still air. Although it has less mass (and is therefore less expensive) OC-SPF isn’t a good vapor barrier, and it gets knocked for this.

CC-SPF. Closed-cell spray polyurethane foam cures in place and stays rigid. But unlike open-cell products, its bubbles aren’t irregular or open. The bubbles form by trapping “reaction gas,” which offers insulation properties. With the higher-density foam you get higher R-value around 7 per inch. CC-SPF weighs in at 2.0 lb. per cu. ft. and partially because of its greater mass, it costs more per R than open-cell foam. Unlike its open-cell cousin, CC-SPF is a good vapor barrier and is often code-approved as such. What’s more, CC-SPF can add to the sheer strength of a wall, and in recent tests when sprayed under a roof decking it can help defeat roof uplift (Google search University of Florida, Dr. Prevatt, foam).

By the way, the polyurethane foams you see in molding are of even higher density than CC-SPF, weighing 30 to 40 lb. per cu. ft.

Even after you compare cost and vapor barrier performance, note that some foams are inappropriate in certain applications. Open-cell foam should not be used below grade because it can absorb water. Since water is a poor insulator (relative to air), foam that is soaking wet has dramatically compromised thermal performance. You’ll also want to spec closed-cell foam in tight areas or around utilities where you can’t get the bulk and thickness required by an open-cell product to achieve the designed R-value.

The latest in the Gravitas Design Series: The Gallatin

The Gallatin plan below is a home we designed for a client in Idaho. This is an efficient single level plan with very modern lines and contemporary building materials.  The Owner’s Suite has a large split bath with integrated walk in closets. The Owner’s baths share a connection through the steam shower. The materials for this project speak to the high desert site and the low western roofline is a response to the need for protection from the late afternoon sun and rangeland fires that can blow in from the west. Many of you are familiar with our log and timberframe vernacular but every once in a while we want to show you something differnet from our varied design experience.

Our scope of work runs from design through construction drawings and can include site analysis, permitting, HOA approvals, stamped engineering, interior design, renderings, animations and sun shadow studies.  If you would like to use our plans in your marketing material we can personalize the plan book to include your company logo and information. We have just introduced a new format that includes links to a fly around movie of each plan and professional renderings. This provides a way to increase your presence in the industry and instantly upgrade your marketing efforts at no cost to you. Please contact us for more information on this service, for “paper specs” or visit our FAQ page online for more details. 

The Gallatin - Modern Home Design in Boise by Gravitas

Idaho Modern Home Exterior

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