Working link to your Revit cloud model in Forma Data Management.
Working link to your Individual Forma Board
DF sheet set at D size, 30 by 42 inches, six sheets. Delete any blank sheets.
Screenshot of your Insight result alongside your Week 3 Forma result.
Week 3:
Week 4:
Design memo of 300 to 400 words: what survived the handoff, what you rebuilt, what assembly choices you made and why, and where Revit and Forma disagreed.
What survived
The building’s geolocation, including true north and the terrain, survived the handoff. The approximate massing (all eight stories with the correct footprint and stepped mass) and the window/balcony pattern also survived.
What I rebuilt
I rebuilt the envelope and remodeled all the core elements (shaft, stairs, elevator).
What assembly choices I made and why
The upper wall is made of a fiber-cement rainscreen, a 1" ventilated gap, Type X sheathing, 4" HempWool, 5-ply CLT, and 2x Type X gypsum board, for an R-value of 26. I chose this to meet Type IV-B code requirements and make my building more fire-resistant. I chose wood over concrete for the upper floors because it sequesters carbon, making it more sustainable.
Typical floors are made of oak, 1.5" gypcrete, an acoustic mat, 7-ply CLT, and 2x Type X gypsum board. They have a two-hour fire rating and acoustic separation for residents.
The ground floor wall is cement plaster, 8" CIP concrete, 5½" HempWool, and Type X gypsum board, for an R-value of 21.2. (HempWool is a product I use in my research, but I used cellulose as a stand-in for the carbon analysis since HempWool isn’t in the library.) I wanted something strong enough to carry the seven floors above it.
I also chose 6" concrete with a vapor retarder and 2" XPS for the standard slab on grade.
Finally, I included a green roof to assist with stormwater retention and reduce the urban heat island effect. It is made of sedum + 6" growing medium, drainage, root barrier, cover board, and 5½" polyiso. I removed the balconies from the rooms next to the green roof and replaced them with windows, since a balcony level with a green roof made little sense.
I chose triple-glazed windows. The north windows have a higher solar heat gain coefficient (0.41) than the south/east/west windows (0.26) since the north side receives very little direct sunlight. Forma’s sun hours analysis showed the south elevation gets the most direct sun, so I added 2' overhangs above its windows to block high summer sun while admitting low winter sun.
Where Revit and Forma disagreed
The Forma massing estimated 19.68M kgCOâ‚‚e total carbon, while the Revit model estimated 17.32M kgCOâ‚‚e. While this was only a 12% change, there was a 56% change in estimated embodied carbon: Forma estimated 2.82M kgCOâ‚‚e and Revit 1.23M kgCOâ‚‚e. Since Forma lacks precise information about my materials, its estimates rely more on generic defaults, making the numbers less reliable.