Lesson: Forming Foundations

Authors: Peter Anderson, Wade Goodridge, Sarah Lopez, Natalie Shaheen, Ann Cunningham 

Class Size 

  • Written for 15 students. Scale as needed, ensuring adequate assistance is available during the build phase. 

Lesson Structure 

90 minutes 

  • Experience the 2 sizes: 20 minutes 
  • Draw, calculate area, place door: 35 minutes 
  • Cut cardboard base and build balsa base: 35 minutes 


Students will be able to: 

  • Decide what dimensions to use for the floor plan of their structure. 
  • Calculate the area of the structure using student-determined building dimensions. 
  • Build a template and a base for the structure, which matches the student-determined dimensions, using chipboard and balsa wood. 

Prerequisite Knowledge 

  • How to calculate the area of a rectangle 
  • How to use a Sensational Blackboard to draw straight lines (Introduction to Drawing)
  • How to label parts of a drawing (Intermediate Drawing)
  • Basic construction skills with balsa wood: measuring and cutting lengths of balsa, using adhesives to join pieces of balsa (Woodworking)


  • Nonvisually accessible measuring tools:  
    • Braille ruler 
    • Braille calipers 
    • Click rule 
  • Nonvisually accessible drawing tools: 
    • Sensational BlackBoard (SBB) 
    • Notched T-square 


  • 2 x 4 lumber in the following lengths (see notes in Preparation for more options) 
    • 10’ - 4 per class 
    • 12’ 5” - 2 per class  
    • 9’ 5” - 2 per class 
  • 1/4” x 3/8” x 45” balsa wood piece - 1 per student 
  • Sensational BlackBoard - 1 per student 
  • Sensational Drafting Board (optional) - 1 per student 
  • Office paper, 11” x 17” - 1 per student + 6 extra 
  • Pen, ballpoint 0.5 mm - 1 per student 
  • Ball stylus 2.9 mm - 1 per student 
  • T-square, notched on one side - 1 per student 
  • Accessible calculator (e.g., talking calculator, accessible mobile app) - 1 per student 
  • Accessible measuring tools (e.g., Braille ruler, click rule, Braille calipers) - 1 per student 
  • Chipboard (i.e., cereal box cardboard), cut to 12” x 16” - 1 sheet per student + 6 extra 
  • Paper cutter, roller-blade style - 1 per 3 students 
  • Cutting mat - 1 per 3 students 
  • Scissors, adult (not a class set) - 1 per 3 students 
  • Balsa wood, 1/4” x 3/8” x 4” - 1 piece per student 
  • Razor (crosscut) saw - 1 per student 
  • Angle/length cutting jig - 1 per student 
  • C-clamp - 1 per student 
  • Angle shear - 1 per 2 students 
  • Balsa chopper - 1 per 5 students 
  • Glue dots, permanent, 1/2” - 10 per student 
  • Braille 1-10 number stickers - 1 page 
  • Glue guns - 1 per 2 students 
  • Old coffee cans - 1 per 2 students 
  • Poster paper to catch hot glue - 1 per 2 students 
  • Large print and Braille name labels - 1 per student  

Note: Refer to Accessible Lab Equipment & Instructional Materials for additional information regarding specialized tools/materials. 


  1. Cut chipboard into 12” x 13” rectangles - 1 per student + 6 extras 
  2. Place each 2 x 4 flat on the ground (4” side down) in a low traffic area to make 2 squares on the floor.  
    • One 10’ x 10’ square, using 2 pieces 10’ long and 2 pieces 9’ 5” long 
    • One 10’ x 13’ square, using 2 pieces 10’ long and 2 pieces 12’ 5” long 
    • Note: If it is convenient, attach the boards to the floor or to each other so that the boxes are more stable, and do not move when students interact with them. This could be done with tape, Velcro, screws, etc. or the boards could be cut longer than the specified lengths and notched so they fit together like Lincoln Logs. 
  3. Group the drawing materials for quick distribution: Sensational BlackBoards, 11” x 17” paper, pens, measuring tools, and T-square rulers 
  4. Group the chipboard cutting materials into stations (one station per 3 students) with chipboard squares 12” x 13”, paper cutter, cutting mat, and adult scissors  
  5. Create a buffet line for the balsa cutting materials: Balsa wood, razor saw, angle/length cutting jig, C-clamp, and glue dot rolls. 
  6. Set aside a workspace or building station for each student to keep supplies and work on their model. They will use this station as they construct their model throughout lessons MB1-4, and will keep their in-progress work here between lessons. Label stations with students’ names. 


Experience the 2 Sizes: 20 Minutes 

  1. Introduce the activity.   
    • Tell. “We are going to make our first design choice today. The floorplan is where your activity happens and has consequences for other parts of the building. We will also build the bottom or base of the final model in this lesson.” 
  2. Review constraints.   
    • Tell. “Our constraints tell us that the dimensions cannot exceed 10’ x 10’ x 13’. We chose these constraints because structures under 150 square feet don’t require a permit for building in most cities. So if you had the time, materials, and land, then you could build this structure to scale at home without getting a permit from your local government.” 
  3. Review criteria.   
    • Tell. “Think carefully about what you are putting into the space. Recall the thinking you did earlier about what you would do in this space. If your weightlifting equipment or loom is 8 feet tall, how might that factor into your choices about your floor plan and building dimensions?” 
    • Do. Solicit answers from students. 
  4. Consider tradeoffs of 10’ x 13’ and 10’ x 10’ floorplan.   
    • Tell. “These constraints are a bit abstract, so we thought we would start by giving you an opportunity to explore a 10’x13’ rectangle and a 10’x10’ square.”   
      • 10’ x 13’ 
        • Tell. “This is the largest structure footprint and shortest structure height possible given the constraints. The remaining 10’ measurement includes a roof of some sort and any headroom, which means your ceilings will be lower than the customary 8 -10’, as the roof itself will take up several feet. If you are shorter than 6’ tall, the structure should be livable, though perhaps stuffy when heated.” 
      • 10’ x 10’  
        • Tell. “If you would like a 10’ x 10’ room, you will have 13 feet of height and your ceiling can be the usual 8 -10’ high and leave plenty of room for a roof. For tall people, high intensity activity, or tall gear, this is a better choice.” 
  5. Experience room in two groups.   
    • Do. Have students explore the 2x4 footprint boxes on the floor. Divide the class in half and introduce the 10’ x 13’ footprint to one group and the 10’ x 10’ footprint to the other group. When most students are complete, have the groups switch and explore the other footprint. 
  6. Illustrate ceiling height. 
    • Do. Have students explore possible ceiling heights. How you do this will depend on your physical space. For example, in a space with normal 7 ft. ceilings, you may have students stand on a chair and feel the ceiling, and then imagine adding a foot or two beyond. In a space with high ceilings, you might put a mark or object on the wall at a specific height (i.e. 8ft.) and have students touch it. 
  7. Other options for size and shape. 
    • Do. Direct students to return to their tables.   
    • Tell. “Your building does not need to be a square, nor does it need to be one of these two sizes. However, the overall dimensions of your structure must not exceed 10’ x 10’ x 13’. You are the ultimate decision maker about this project; make your decision carefully.” 

Draw, Calculate Area, Place Door: 35 Minutes 

  1. Draw the floorplan.   
    • Do. Pass out the Sensational BlackBoards or Sensational Drafting Boards, T-square rulers, and 11” x 17” paper.   
    • Students Do. Direct students to measure and draw the floor plan for their houses where 1 foot = 1 inch. Students should label these distances on their drawings, and use a T-square for any 90-degree angles. If students wish to label where furniture or other equipment will go during this time, that is encouraged once they have the floorplan outline drawn accurately. Students should either label these objects or create a key to indicate what objects are shown. 
    • Do. Instructor may need to show students how to tape paper to drafting board, place and use T-square and triangles, or hold and use writing utensils. 
  2. Calculate area of floor plan.   
    • Tell. “Next you must calculate the area of the floorplan and record it on your paper. Can anyone tell me how to calculate the area of a rectangle?” For a rectangle, this is length by width. “For other shapes, breaking the shapes into rectangles or triangles and calculating their areas and adding them up is typically the way to go.” (This is called a composite area approach.) “Go ahead and calculate the area of your floor plan using your chosen dimensions.”
    • Note: Help any students that have non-rectangular floorplans. 
  3. Monitor calculations.   
    • Do. Rotate throughout the students and be certain that the area calculation is done correctly. After you have checked, direct students to record the maximum building height for their structure (either 10’ or 13’) on the same page. 
  4. Door placement.   
    • Tell. “The second design choice is where your door will go and what size it should be. The standard exterior door in America is 3’ wide and 6’ 8” tall according to the International Building Code, but you can choose whatever size you think is best for your space. Most furniture is designed to be able to get through a door 3’ feet wide. If you need to bring something in that is wider than that and you can’t just tip it sideways, adjust the door width to something larger. You may also consider double doors in this situation.” 
  5. Direct students to measure and mark their door on the floor plan.   
    • Teach. Most doors swing inwards on houses, so plan a path for the door to open that doesn’t have furniture in the way. 
  6. Work time.   
    • Do. Circulate through students as they draw. Check student floor plans for accuracy, that drawings are to scale, that corners are drawn using the T-square, and for labels. 

Cut Cardboard Base and Build Balsa Base: 35 Minutes 

  1. Introduction.   
    • Tell. “Now we’re going to cut out a chipboard template to represent your building’s footprint, which will make the building process easier. If you make a mistake with the chipboard, get a new piece.” 
  2. Cut the chipboard.   
    • Do. Pass out the sheets of chipboard. Direct students to measure and cut their cardboard footprint with the paper cutter. If possible, align the footprint in the corner of the cardboard sheet to take advantage of the precut sides of the chipboard.   
    • Students Do. 
      • Notch the two lengths of the structure on the edges of the chipboard with the scissors. 
      • Check that the two notches are at 90 degrees to the edge with the T-square. 
      • Cut lines carefully, starting at the notches with the paper cutter. 
  3. Check student templates.   
    • Do. As students finish their chipboard template of their floor plans, direct them to record their name on it, move to the building lab, and find their station. 
  4. Announce the base.   
    • Tell. “We are going to build a wooden base that goes around the bottom of your structure.  It will help your building hold together on its own without a foundation under it.” 
  5. Pass out the sets.   
    • Do. Call students up to the materials table a few at a time. Direct students to get: Balsa sticks, an angle/length cutting jig, a crosscut saw, and 8 glue dots. They may also use other cutting methods described in Woodworking. 
  6. Build the base work time.   
    • Do. Direct students to build the base of their structure. They will need to cut four lengths of balsa based on the size of their plan, and glue them together. Circulate around the room and observe students for safe tool use, adherence to the plan, and help students adjust the lengths of their cuts. Their final base should look something like the following picture. 
    • Four narrow pieces of balsa form a rectangular base.
  7. Extension.
    • Students who finish early should check that their corners are square with a T-square and then may build a door frame where they have located it on their drawing. A door frame will consist of two small posts sticking up from the base, with a crossbeam on top. 
  8. Glue wood base to template. 
    • Do. Have students glue their finished balsa base onto their chipboard base and label both with their name. Their base should look something like the image below. 
    • Chipboard has been glued to the underside of the rectangular base from the previous image.
  9. Cleanup.   
    • Students Do. Students should dispose of any materials they don’t wish to keep and return any tools to where they got them. 

Post-Lesson Check 

At the end of this lesson, students will have a rectangle joined together with glue dots on a piece of chipboard. Small errors on this portion may compound in the other lessons. Inspect these with a small T-square to be certain angles that are meant to be 90 degrees are. Also check students' bases to ensure they adhere to design constraints.  

Standards Alignment 

NGSS Standards Alignment:

  • SEP 3 - Planning and carrying out investigations 
  • CCC 4 - Systems and system models 
  • HS-ETS1-2 

CCSS Standards Alignment:

  • CC.9-10.R.ST.3, CC.9-10.R.ST.4, CC.9-10.R.ST.7, CC.11-12.R.ST.3, CC.11-12.R.ST.4, CC.11-12.R.ST.7 
  • CC.9-12.G.MG.1, CC.9-12.G.MG.3, CC.9-12.G.GMD.4 

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