In my recent pursuit to model every building in the registry of historic buildings, I found that there are two located in my hometown of Germantown Wisconsin. One is surprisingly close to the house that I grew up in, that being the Jacob Schunk farmhouse.
It was built in 1858 for German dairy farmer Jacob and his wife Mary Ann. They lived in the house until their deaths, passing it onto their son and his family. The area around the house is still untouched, though the land nearby has been developed for other residences. It is incredible to me how many times I have driven past the property without even realizing there was a house there, let alone one from 1858. The old trees along the road really camouflage the property. A hidden gem.
In my recent study of Helgaland, I ran into a dilemma. What is the best way to model vertical log walls in Revit?
The first thing I tried was using a bump map texture of vertical lines to approximate the log shadows. This didn’t work nearly well enough and I realized I needed to find a way to actually model the round logs. The shadows are very important for creating realistic renderings of the exterior of the building and a bump map texture just doesn’t do enough.
My next idea was to use vertical wall reveals to create the voids between the logs. See the image below for how this looks in plan view.
Implementing this was more difficult than I hoped. Vertical wall reveals are finickey when it gets near the corners. I solved this by adjusting the walls to be joined by miters. The stacked wall shown below has wall reveals only on the bottom wall type. I think this looks fantastic and achieves exactly what I was going for!
Still there are some issues with this technique. The wall reveals don’t know how to work around window cutouts. They also still have difficulties around some corners. The corner below still has a sharp point, even through I’ve tried the same method as the half wall in the picture above.
So that works well enough for short wall sections with no windows or doors. Unfortunately, many walls have window and doors.
The next thing I tried was to keep a wall for the windows to host to, but add architectural columns on top of them to provide the depth of the logs. The idea is that the columns can be capped in height to stop below the window, and another level can be added above the windows. This technique would be extremely time intensive, and only would really work for existing conditions as moving walls would be a bear.
I’ve seen some forum posts online where people suggest using curtain walls to accomplish this. Usually, people are looking to create horizontal log walls, but in my case I’m creating vertical log walls. The idea is to create a circular mullion profile with the diameter of your logs. Then, set the spacing of the mullions to the same dimension as the diameter (or slightly less to get some overlap). This gives a pretty good log wall effect.
Perhaps the coolest house in La Crosse Wisconsin is, in my opinion, Helgaland. Helgaland was the summer residence of Mr. A Gundersen and his wife, Helga. Dr. Gundersen is known as the founder of Gundersen Health System. The home was designed by Bentley and Merman Architects in the year 1918. It is located smack dab in the middle of the Mississippi river on the north end of Pettibone Island. It is so significantly seperate from the city of La Crosse itself, it must have been considered Dakota Minnesota when it was built. All documentation from the architects say it is located in Minnesota, though it is clearly within La Crosse county borders today.
The site itself is very unique. Pettibone park is seen along the bottom 2/3 of the island. The north 61 acres are the site of Helgaland. The property is still in the Gundersen family to this day. Half of the reason this is the coolest house in La Crosse is simply due to the property itself. It is surrounded by the Mississippi on three sides, with a private forest on the fourth side.
The designs for the home were found in the La Crosse Public Library archives. They are part of the Bentley, Merman, and Skogstad collection. The amount of archived architectural drawings is incredibly cool and I know I will be checking out many more of these when I get the chance.
The level of detail is inspiring. Every little element of the building is hand sketched.
I think it is fascinating how they used all of the limited sheet space. The sheet below has a long elevation on the bottom half, but then on the top half two details are shown oriented to the narrow side of the sheet. Very cool. This is not the only sheet using this technique. Frankly, it makes many of the sheets very difficult to read, but cool nonetheless.
Elevation and Wall SectionWall Section, Interior DetailsInterior Section thru Stairs
Revit Renderings
I modeled the building in Revit as a bit of practice in using the architectural tools. There are so many little details that give this home its character. I have a lot of work to do in creating these details.
View from South East Corner
The view of the front door below shows off some framing details I added. These details are generic models, modeled in place.
View of Front Door
The back door has similar framing details.
View of Back DoorBack of House, Facing North Up Mississippi RiverView from Back of House
The exterior log walls are such an important design feature of this house, I had to figure out a way to model them. Generally, Revit prefers straight and flat walls. I haven’t used the complex wall tools in Revit much, so this project was a great reason to expolore them.
This first technique that I tried was using vertical wall reveals spaced 9″ apart (Because the logs are approx. 9″ in diameter). This only worked well in long stretches of walls, with no windows. It fell apart quickly near the corners as it is disrupted by the joined wall sections. See the image below for the limitations of this technique.
West Side Entrance with Wall RevealsView from West Side of Home
After the vertical wall reveal concept showed many flaws I started brainstorming. The second idea I had was to use architectural columns to hand place each log in the wall. With just columns, the windows and doors would have nothing to host to.
I started by cleaning up some previous code. I realize now how important keeping a consistent data structure can be. I want to organize my groups using some sort of color code. Yellow for user input, Green for user output, red for calculations or something like that. I’ve seen something like that online before but I can’t recall where.
There is a very powerful tool for Grasshopper within Rhino 3D. The Ladybug Tools collection includes many add-ons that allow for energy calculations, lighting calculations, air flow calculations, and much more. Building detailed models for energy and light simulations has never been simpler using Rhino’s speedy modeling tools.
I find the visual programming workflow that Grasshopper provides to be very intuitive in developing a model. Having the ability to simply export the model to .gbxml, we can verify our results in other HVAC load calculators.
For this study I am using the model of a gym in Davenport Iowa.
Preliminary Rendering
The building was built as a warehouse, with wood framed construction, and a mix of conditioned and unconditioned zones. The study is to determine whether the existing HVAC equipment is adequate for the existing space, and what might need to be done to improve comfortability.
Honeybee Model showing Roof, Exterior Walls, Windows, Doors
In terms of models, this one is pretty interesting. The mix of conditioned and unconditioned spaces as well as the mix of single story (full height) and two story (half height) rooms makes the construction unique.
Roof and Ceilings Removed showing Interior Walls, Floors
I also think there are some quite simple things to fix that would make the space more efficient. For one, the only windows in either warehouse space are facing north. The sun never gets a good angle on them, as shown in my preliminary light simulations.
Annual Light Study
Because of this the garage doors tend to be open, for light and airflow. This solution is usually adequate. If the space were ever to be conditioned, it may be ideal to replace one or more of the garage doors with clear garage doors. This also could cut down on the intense glare late in the day on the east wall of the building. I intend to adjust the materials of the doors in my Honeybee model to test the effect of clear doors.
Better Model with Internal Walls
The northern windows are up high. Changing one window to a louver for ventilation may help keep hot air out in the heat of summer. With glass garage doors, they can be kept shut, or only up a foot or two to allow cool air in from below.
These simulations were generated through my Grasshopper definition. It can be seen in full below:
Continue reading to read my explanation of how it works. I often refered to the Philipp Galvan Design YouTube channel for guidance in making these simulations.
I start by creating a Honeybee Model. First we define our rooms. Each room is created using closed polysurfaces(Solids).
This is the icon for a brep. We use icons like this one to bring geometry from Rhino into our Grasshopper definition.
The building type can be set next. There is some easy to use dropdown menus for simple things. HB Climate Zones are the ASHRAE climate zones. I may have to move the “HB Building Programs” selector to each individual room block, to allow different room use cases. I selected Warehouse for now to approximate a general commercial use for the building. As I look at this block, I should move the construction set by climate component back, and the Building Programs up to each room block. Also add relays.
This first unique component is called “HB Intersect Solids”. Because we are doing a more complicated model with every room modeled there are some locations where the
This idea of requiring a boolean toggle is common through this code. Many of the Honeybee components take significant time when they run. Having a quick way to turn them off allows you to edit specific parts of the code at once.
