Cottonwood Modern

January 14, 2013 — 15 Comments

Wow! I can’t believe I have let it go almost three months without an update on the Cottonwood Modern project. I actually have about three of four posts started on this project that I just haven’t been able to find make time to work on. Eventually I will focus on the fireplaces and the tornado shelter/ safe room, but today I wanted to catch up and take a look at the soffits.

New Project 3d view 02

This is a 3d image of this house and I thought it would be beneficial to include here just as a reminder of where this project is headed. The cantilevered rooms on the rear elevation have really started to take shape and now the pool has been dug in and received its structural shell (gunite), I think it is safe to safe the people who visit the site are starting to be able to visualize where we are going.


Cottonwood Modern main living room framing

This is the view of the Main room … I am standing on the ground looking into the cantilevered space that’s on the left – the kitchen will be on the far right of this picture. You can see where the transition will take place by looking at the framing where we have lowered the ceiling height. Kitchens are typically a more intimate space and we can to make sure that the scale reflects this concept. The fireplace in this image is an “Isokern” fireplace … I have a post that will focus on these types of fireplaces in the next week or two so I will largely ignore them today.


Cottonwood Modern pool shell with void cartons

This is the pool, well, it’s the hole for the pool. If you live in an area of the country/world where pools are not all that common you might be thinking to yourself “That pool is lined in cardboard? Those Texans don’t know what they’re doing.” It’s okay, we actually do know what we’re doing. The area where this project is located has very active soil (which means it expands a lot when it gets wet and dries. The cardboard you are looking at are called “void forms.” This is a structural pool so you see the concrete piers (the concrete posts that have rebar sticking up) are located and the pool shell will get poured on top of the cardboard which will decompose over time and create a “void” between the ground and the bottom of the pool shell. That means that when the ground expands and contracts – as it gets wet and then dries – it won’t move the pool. This is important for lots of obvious reasons but particularly so because we have an infinity edge that runs along the entire right hand side. If that edge isn’t perfectly level, the water won’t flow over the edge evenly and will look terrible.

We don’t like terrible in my office.


Cottonwood Modern pool shell with frozen water

Here is a view of the pool after the shell has been poured. You might be surprised to know that the water that has collected in the middle of the pool is actually frozen solid (people don’t think it gets cold in Texas … it does, just not for months on end, more like a week or two.)


Cottonwood Modern rear elevation looking towards pavilion

From this picture you can look back from the opposite end of the pool towards the pool pavilion … way … in … the … back. This is a 5 acre lot and the house and pool run across its width so that most of the lot still looks and feels undeveloped, raw, and in its natural state.


Cottonwood Modern cmu work at pavilion steel framing

The pool pavilion is still a ways off but the steel is in place – most of it will remain exposed and visible from the underside of the pavilion roof. The masons were on site blocking out around the fireplace and the grill area and I thought it would be interesting to show how the steel was embedded into the concrete block. The edge of the roof cantilevers out beyond the line of where the CMU (concrete masonry unit) ends so we needed to extend it into the wall to achieve the structural support we needed.


Cottonwood Modern steel post at pavilion

This picture isn’t particularly interesting other than the holes that were cut into the steel column – or more specifically why those holes were added. Since the steel is exposed along the ceiling of the pavilion, we needed a way to distribute power to things like ceiling fan … but who wants to look at an electrical conduit running up the side of an exposed steel column? I don’t, and you shouldn’t either.

The holes allow us to run the power up inside the steel column. Maybe I am overly excited about something so insignificant but these are the little things that you don’t learn about in school.


Cottonwood Modern front entryway

This is a look at the front approach – the large window on the right hand side is the kitchen and you can see though this window all the way through the main space out into the rear of the lot. This view – and the trees on the lot – are why the owners bought the lot and it’s our jobs to take full advantage of the resources presented..


Cottonwood Modern roof deck equipment layout

This is a picture of some on-site problem solving. We ended up with more equipment on the roof that we had originally planned for and although we had the space to accommodate that equipment, we still needed to work out where it would go as well as allow for convenient servicing of that equipment.All told, there are 4 air-conditioning compressors for the main house, two for the garage, and a generator if the power ever goes out. These are cut out templates so that we could review our options with the HVAC contractor.


Cottonwood Modern cantilevered boxes rear elevation

We are back at the rear of the house looking at the cantilevered rooms. All of these walls are mostly glass so you will be able to see the soffits that project out from these rooms. As a result, they needed to be designed. Maybe it’s just me but I am a HUGE fan of designed soffits. They don’t have to be ridiculously expensive but it is a feature that is largely relegated to flat painted surfaces with the idea that nobody will look at them. We do those kind as well but not on a house like this. On this house, we have something much nicer.

Cottonwood Modern mahogahny soffit 04

Cottonwood Modern mahogahny soffit 01

We have mahogany boards that will receive a slight stain finish to even out the color and protect the wood. We originally were going to use Douglas Fir boards – which would have looked great but we found out that the mill had a deal on mahogany boards at 25% of their normal cost (we got these boards for around $2.25 a board foot.)


Cottonwood Modern mahogahny soffit tongue and groove boards

We had the boards custom milled to have a square edge reveal so that the boards would be articulated and their pattern more discernible. Normally tongue and groove boards don’t have a gap and the joint is expressed in a “v” pattern. The square reveal is just a slightly modern interpretation of a more traditional detail.


Cottonwood Modern mahogahny soffit 02

Another look at the soffit with the mahogany boards in place and the pattern we designed in the corners.


Cottonwood Modern mahogahny soffit 03

This is another look at the soffit but if you are observant, you will notice the gap at the right hand side. This gap is in place to allow the passage of the stone veneer up and through where the soffit is located. This is a cleaner detail than framing the soffit all the way back to the sheathing (plywood) and then having a new flashing condition.

As I mentioned in the beginning, there are a few other partially complete articles I am working on, things are just now starting to move a little faster on the job site and there are all sorts of interesting things to share.


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  • Damilola, Nigeria

    Hi Bob! Thank you for this post. I first read your blog late last year and I have learnt quite a bit from you. I also really appreciate you post about the architect’s salary. Looking forward to your next update about this Cottonwood Modern project 🙂

  • Very nice work, Bob!! Cant wait to see more advancements!!

  • Pingback: Gorgeous detailing from @bobborson – ‘under construction’ « Mark Stephens Architects()

  • Kat

    Whenever the AIA convention gets around to Dallas, I hope that some of your projects are on the tours! I’m glad you explained the cardboard because I totally looked at that picture and was like, “What the….?” I’ve never had a project with a pool; it’s too cold up here!

  • Ron Campbell, Las Cruces, NM

    Great post, Bob. I’m looking forward to watching this project develop. And, for the record, we don’t much like terrible in my office, either…

  • Mikheil

    Bob, this is a post with real substance, such a kind, as a reader, I love ‘Life of an Architect’ blog for. Thank you for sharing your experience.

  • Shanley


    I would have thought the stone veneer would have been installed before the soffit which seems more of a finish carpentry item. It probably would have been easier for the mason to lay up the stone if he had full access instead of having the soffit in place. Not to mention the possibility of getting mortar all over the beautiful mahogany…. Is there method in this madness?

    • as I understand it, the soffit material is going up now because we had to buy it early in order to get the mahogany at the deeply discounted rate. As you know, means, methods and sequencing is on the contractor and this is the route he decided to take. There is a trim board that will get applied where the soffit and the stone veneer come together so the masons will have space to work and this condition doesn’t happen but in maybe 1% of the project.

  • Hi Bob, looks good

    I know you will probably have it all figured out and will answer the question in a later post, but I have a small question. Actually two

    The cantilevered areas look like they will be getting frameless glass, or at least some sleek framing and not the conventional members. I figure from the fact that a) the supports are round, so they are probably freestanding and not at the glazing surface and b) the whole point of the cantilevered cube is emphasized by the sleekness of the envelope.

    First question – I know the sketchup model shows some horizontal members in the glass, but what kind of sill detail are you going to follow? Do you recess the glass in the floor in a channel and make the inside floor surface continue till the edge – Or do you run a member at the bottom? I have been trying to perfect a seamless detail for the floor condition for a while now and was wondering how you do it

    Second question is kind of related – If you use insulated glass(glass+gap+glass), how do you treat the vertical junction at the corner of the cube. We normally do a mitre-edge detail on 12mm toughened glass panels, but that isnt possible on a double glazed unit, so we have resorted to fabricating a custom steel vertical at the corner which has got “u”s or “c”s to receive the unsightly edging of the double glazed unit. Are you planning a vertical member at this junction or does the appeal for a corner-less room mean you specify a laminated or single glass.

    Nice work on the soffits, are you uplighting them? didnt see any wires dangling down

    Thnx, Ak

    • Interesting questions – I’ll do my best to answer them.

      We rarely (if ever) bring glass all the way down to the floor set into channels. While it is a beautiful detail, especially at this site, potential movement and on-going maintenance make it a premium detail and we are generally okay with lifting the glass off the floor 2″ to accommodate such considerations.

      As for the corners, we are staggering the way the glass overlaps – but since there will be window spacers and compound in the corners that you can’t remove when you have insulated glass, we have some custom “L” brackets in the corners. I have attached a quick drawing here that will hopefully make things a bit more clear

      • Interesting.. I’d like to share with you a photograph of an ongoing project where I was debating how to tackle these 2 issues. The glass was put in a few weeks ago and (fingers-crossed) it seems to be working so far, although I will agree with you on the ongoing maintenance aspect. We custom fabricated the corner members to act both as a structural corner for the glazing and as a cover plate for the ends of the insulated glass unit

        It’s heartening to know someone else out there is also thinking of the same stuff

        • Kat

          The detail is gorgeous! I just want to sit here and stare at it. I hope you’re in a warmer climate.

        • it’s a hard detail to pull off in any climate other than “moderate – that looks nice and clean