Since we launched the first version of our Calculation Sheets, we’ve been showing it to many practicing structural engineers and received a lot of valuable feedback on how to improve readability and make design review easier.

And we listened!

Now we’re running every project with this new version Calculation Sheet.

As always, we welcome your feedback and please let us know how we can support your construction projects!

In our last article, we walked you through our design methodology for lateral force resisting systems (LFRS). The Structural Engineering Association of California (SEAOC) includes a canonical example in the International Building Code (IBC), with particular emphasis on seismic design. Therefore, we’d like to show you a side-by-side comparison between Genia outputs and the SEAOC solutions included in the IBC SEAOC Structural/Seismic Design Manual Vol. 2.

Project Setup

The SEAOC design example is a four-story wood-frame hotel structure assumed to be located in Irvine, CA at Longitude = -117.8320, Latitude = 33.6800, Zip Code 92614. The gravity-load framing system consists of wood-frame bearing walls. The lateral-load resisting system consists of wood-framed bearing shear walls (common box-type system). The building elevation is shown as above.

Since the design manual only provides a typical floor layout and the building structure looks the same for every floor from the side view, we make a reasonable assumption that the floor layout is identical across all four stories.

The design manual also provides a roof map with a framing plan. We only use the roof map and do not consider the framing plan when we reconstruct the architecture in CAD. As we follow the steps above, we reconstruct the architecture model from the PDF drawings in AutoCAD here.

Design Results Comparison

As we follow the design steps outlined in the previous article, we have produced the following files for the design example:

• Structural Drawings

• Calculation Sheet

We therefore present the following comparison between Genia and SEAOC designs:

1. Base Shear Distribution

In SEAOC manual, the vertical shear distribution across four floors is as following:

Here is our calculations in Appendix A.6 of our Calculation Sheet:

Overall, the difference between Genia and SEAOC calculations is less than 5% for all floors due to differences in floor areas originating from the recreation of the structure in AutoCAD.

2. Vertical Distribution of Base Shear to Shear Band

In SEAOC design, the following shear band/shear line layout is adopted:

The seismic force distribution results to each shear line is also presented:

In comparison, Genia’s AI-generated shear line design in East-West direction is identical to SEAOC:

And the calculation results is within 5% difference from SEAOC distributions for the same shear band:

3. Total Seismic Load Distribution to Shear Band, including Influence from Floors Above

In the same Table 1-13, the total seismic loads distributed to each shear band F_tot include both:

• the base shear vertically distributed to each floor and then to each shear band according to its tributary area under the flexible diaphragm assumption, and

• the shear forces passed down from the above floors.

For instance, for Shear Band C in the design example, F_tot = 40,882 lbs.

In Genia’s design, the same shear band is labeled as “floor 1-shearband-3-x”. The design details of this shear band is included on page 38 of our Calculation Sheet listed above. “floor 1-shearband-3-x” is made up of two shear piers with their dimensions and forces detailed below:

The base shear allocated to this shear pier is 19684.69 + 19684.64 = 39369.33 lbs, which is within 5% difference from the SEAOC design.

4. Seismic Force Distribution to Shear Wall

Now that we have checked the seismic load distributions to each shear band are aligned, we want to further verify the load distribution to each shear wall.

For SEAOC design, each shear wall within shear line C bears 951 × 21.5 = 20446.5 lbs

In Genia design, “f1-shearwall-4” and “f1-shearwall-5” each bears 19684 lbs of lateral forces as we have seen above, which is again within 5% difference from the SEAOC design.

Based on the above analysis, we then proceed to the specific shear wall design. Given the similarity of the shear band layouts and force distributions between Genia and SEAOC’s designs, we therefore expect a similar material specifications of the shear wall. Let’s find out!

5. Sheathing Design

In order to meet the lateral forces detailed above, in SEAOC design, they opt for “S1_15/32_10d@2” following our material notation.

In Genia’s design, we opt for “S1_(2)15/32_10d@6,” which uses double sheathing and has the capacity closest to force demand. We understand that double sheathing might be more difficult to construct, which might explain why the SEAOC design prefers single sheathing with a more compact nailing pattern. When we launch our editor interface in the next release, we can open up this option to the end user and let structural engineers to make the decision.

6. Post Design

In the SEAOC design, the post design is derived from the maximum compression. We noticed a calculation error in the ASD Demand Compression, as we follow the formula we should obtain 22.98 instead of 26.28 for the second floor.

Based on the max compression, the SEAOC design recommend the following post design:

In Genia’s design, we factor loads from both gravity and lateral (wind and seismic). Take the west-most post of the example shear line, i.e. “f1-post-48,” as an example:

From these loads, we recommend the following post design (the capacity calculations are included in Appendix C of Calculation Sheet):

There are few comments to highlight as there is some difference in the D+L loads between our designs:

1. When a wall is parallel to a joist, in theory the should also bear some gravity loads from the floor above. Currently, in our model, we are not considering this load passed down from the above and only factoring in the self-weight of the walls.

2. In the SEAOC design, they use 15 psf when calculating the seismic weight of walls but switch to 10 psf when calculating dead loads without explaining why. We continue using 15 psf in dead loads as well.

3. When selecting materials from the catalog, we will recommend the post design that has the closest capacity to the demand. We currently do not have a limit on the size dimension of the post.

Hold-downs

We further recommend the following hold-down for the post based on the max uplift tension:

The SEAOC design chooses continuous rod system, so we cannot make a direct comparison here. Below is their calculations of the max uplift tension:

There are two differences that we want to highlight here:

1. In our calculations, we ignore the effect of M_R, i.e. the counter impact of self weight on the overturning moment for two reasons:

   1. We try to stay with a more conservative approach in our calculations.

   2. Wood-framed shear walls have relatively low stiffness.

2. When considering load combinations, the SEAOC uses M_OT × 0.7, and we use M_OT / 1.4 = M_OT × 0.714, which will cause minor differences.

If we revert the impact of these differences in methods, we will obtain M_OT /d = 541,249 / 19.17 = 28,234 lbs following the SEAOC design, which is less than 5% difference from Genia’s value of 26,799 lbs.

Conclusion

In conclusion, by running our Generative Design on a well-recognized design example and provide a side-by-side comparison between our design outcomes, we hope to add more transparency to our AI-led structural design process and convince the professional structural engineering community about the validity behind our design solution.

It is also worth mentioning once again that we only leverage AI’s creativity in structural layout, a process which is heavily dependent on human experiences today. There is not necessarily a right or wrong answer at this stage but based on experience a senior engineer may have a better sense of whether a structural plan has a higher chance to pass structural analysis and is superior in performance and cost.

However, for the actual calculations, we are on the same page as everyone that AI DO make mistakes and our industry is NOT tolerant to mistakes as people’s lives are at stake if our structural design goes wrong. Therefore to ensure quality, we perform structural analysis WITHOUT any AI in the same fashion as the building codes instruct us and as every human engineer would do.

This article was inspired from conversations with a prospect client as he wanted to see our design results comparison against the canonical example in the SEAOC manual. We thought the idea was brilliant and timely as we just covered in detail the lateral design methodology in our last article, so we added this one in the middle of our series. In our next article, we will resume the normal sequence explaining gravity system design of the sample project near Seattle, WA.

Meanwhile, you may also notice that the Calculation Sheet that we run for the SEAOC example is in different format from our last post. We are introducing a new release of the Calculation Sheet. Many of you have provided valuable feedback on how we could improve readability of the hundred-pages-long document and we listened. Stay in touch for a formal launch next week!

About the Authors

Robin Li is the Co-founder and COO of Genia and now leads product management. After graduating from University of British Columbia, Robin started off his career at Arup as a certified structural engineer, where he designed structures for a high-rise casino hotel in Macaw. Later, he returned to Canada and designed 100+ low-rise and mid-rise structures, including high-end custom homes in timber. You can find Robin on Linkedin or email him at robin@genia.design.

Calvin Zheng joined Genia in 2024 as a product manager. He holds a master’s degree in structural engineering from UCLA and has 5 years of experience designing structures in Los Angeles, first at JCE Structural Engineering Group and later at KPFF.

A. Seismic Load

A1. Methodology

For seismic design, we follow the Equivalent Lateral Force (ELF) procedure per ASCE 7-16 §12.8. The amount of seismic base shear is on the basis of approximate period of the building, site specific ground acceleration and response spectrum curve, site class of the site and type of building system used to resist the lateral forces. This type of analysis should only be used when the building is symmetric, torsion is minimal, no vertical or horizontal irregularities and no discontinuities in the system and where the primary mode of the structure governs the structural dynamics. This means that ELF analysis leads to fairly accurate results for short and very symmetric and regular buildings, which describe this sample project.

A2. Base Shear

According to ASCE 7-16 §12.8.1, the seismic base shear, V, in a given direction can be calculated using ASCE 7-16 Eq. 12.8-2:

where C_s is the seismic response coefficient and W is the effective seismic weight.

The seismic response coefficient can be calculated using ASCE 7-16 Eq. 11.4-3:

where S_DS is the design spectral response acceleration parameter, R is the response modification factor, and I_e is the Importance Factor.

To calculate these values, we include the relevant parameter inputs based on the property location and specifications in this following table on page 9 in the Calculation Sheet and derive the value of C_s. We also check the upper and lower limits of C_s to make sure our calculated value falls within the applicable range.

We also calculate the effective seismic weight W for each floor and the entire building:

With the above values, we are able to calculate the base shear V = 26033.93 lbs.

A3. Vertical Distribution

Now that we have derived the base shear, we then need to distribute it to each floor following ASCE 7-16 Eq. 12.8-11 and Eq. 12.8-12

and

Here are the results as shown on page 10 in our calculation sheet:

B. Wind Load

B1. Methodology

Although the project is located in a seismic-dominant region, we still run structural analysis on wind for completeness. To design the main wind force resisting system (MWFRS) for the building, we follow the the Directional Procedure for Buildings of All Heights as detailed in ASCE 7-16 §27.

Under the Directional Procedure, the process to calculate the wind load involves:

1. Determine the basic wind speed, V.

2. Determine site factors K_z and K_zt :

   1. Velocity pressure exposure coefficient, K_z (ASCE 7-16 §26.10.1) based on the project's exposure classification and reference height above ground

   2. Topographic factor, K_zt (ASCE 7-16 §26.8) based on the distance to hills and escarpments. We set this value to be 1 given the project is not built near a hill.

   3. The ground elevation factor, K_e is set to be 1.

3. Calculate the velocity pressure, q_z (ASCE 7-16 Eq 26.10-1)

4. Determine the internal pressure coefficient, GC_pi (ASCE 7-16 Table 26.13-1) based on the enclosure classification.

5. Calculate the design wind pressures, p.

B2. Basic Wind Speed

As for the sample project, we obtain the following site parameters following the zip code of the location, assuming the project has exposure category B and is enclosed. The basic wind speed for this location is 97.74 mph based on the ASCE 7 Hazard Tool.

B3. Site Factors, Velocity Pressure, Internal Pressure Coefficient

For this project, below are the calculation results shown on page 12 of Calculation Sheet, including K_z, K_zt, q_z and GC_pi .

B4. Wind Pressure

To work out the wind pressure, we follow ASCE 7-16 Fig 27.3-1 and obtain the following values as shown in Calculation Sheet page 12.

For wind pressure calculation, we simplify the building contour, often in complex shapes, to its minimum bounding box and consider the wind pressure applied to the bounding box instead. We believe doing so will not introduce errors as long as the building contour is convex and enclosed, because the x and y components from different sides will add up in effectively a rectangular shape. This assumption should hold true for most of the low-rise and mid-rise residential projects.

In the current version, we only consider Case 1: Full design wind pressure acting on the projected area perpendicular to each principal axis of the structure, considered separately along each principal axis, as mentioned in ASCE 7-16 Fig 27.3-18. Another limitation is that we do not consider torsion effect in the current version, which should not be a problem for wood frames given its nature of flexible diaphragm.

We therefore arrive at the following wind pressure requirements, as shown on page 12 in Calculation Sheet:

B5. Wind Load Distribution

Based on the above wind pressure, we further distribute wind load in x and y directions.

In x direction,

• Roof wind load = q_h × 0.5h × B_roof

• Floor wind load of the i-th floor = q_h × 0.5h × (B_i + B_i+1)

Similarly, in y direction,

• Roof wind load = q_h × 0.5h × L_roof

• Floor wind load of the i-th floor = q_h × 0.5h × (L_i + L_i+1)

This explains how we arrive at the load distribution in Calculation Sheet on page 13.

Note that the Basement is fully under the ground, so there is no wind pressure applied.

C. Lateral System Design

In the above sections, we outline the environmental loading factors based on the location and geometry of the building, which forms the basis of lateral force demands. Based on this information, our generative engine has suggested a layout of relevant structural component validated by our structural analysis engine. In this section, we will walk you through how this layout has been designed by AI, and how we validate the layout in structural analysis and specify material details.

C1. Design Assumptions

1. For the Lateral Force Resisting System (LFRS), our design uses shear walls, and we will be rolling our support for moment frames next month.

2. All exterior walls are considered as shear walls automatically.

3. As we mostly work with wood frames, we also follow the flexible diaphragm assumption for lateral calculations. We also do not consider accidental torsion in our calculations consistent with the flexible diaphragm assumption. We will begin support rigid diaphragms in the next release.

4. We also assume there is no vertical and horizontal irregularity for the property.

5. When the walls do not along across floors, we can support offsets up to 10 ft (3m) and passes along the lateral forces to adjacent shear bands in upper or lower floors.

C2. Shear Band, Shear Wall, Beam and Post Layout

The first step to design the lateral system is for our Generative AI to suggest layout options of shear bands. A shear band is similar to a "shear line" or a "braced band" but considers slight offsets between shear walls and beams that form the same shear band.

Referencing to these shear band layout, our Generative AI engine therefore proposes layouts of shear walls, beams and posts that actually form these shear bands, as shown in Calculation Sheet.

C3. Tributary Area

After the shear bands are established, we establish the tributary areas for each shear band following the "half-half" approach under the flexible diaphragm assumption. These tributary areas are depicted on page 37-38 in Calculation Sheet:

C4. Lateral Forces on Shear Band

In Calculation Sheet, we include summaries of seismic and wind lateral force distributions on each shear band for each floor.

We obtain these numbers by following:

1. Obtain the seismic and wind load per square foot. For instance, the seismic shear for Floor 2 in x direction is 13855 lbs, and the area of the floor is 2453 sf. Therefore, the seismic load per square foot is 13855 / 2453 = 5.648 psf.

2. Calculate load by multiplying the tributary area with the load per square foot. For example, the tributary area of "f2-shearband-2-x" is 849 sf, so the seismic force distribute to this shear band is 5.648 × 849 = 4797 lbs.

The same approach is repeated for each shear band across all floors in both x and y directions.

C5. Shear Band Design for Top Floor (without Force Transfer)

As we have now distributed forces to each of the shear band, the last step in designing the LFRS is to design the specific structural components within each shear band.

We follow the segmented approach listed in American Wood Council Special Design Provisions for Wind and Seismic (AWC SDPWS) 2018. To demonstrate how we do it, we will use the same shear band as above "f2-shearband-2-x".

Step 1. Construct the "wall pier"

When we model the architecture, we may chop up walls into segments and label them accordingly to reflect differences between interior and exterior walls. For instance, within "f2-shearband-2-x", wall-29 is an interior wall and wall-18 is an exterior wall. They are labeled as separate walls in our architectural modeling.

However, when two shear walls are aligned and next to each other, typically they would be sheathed together and work together to resist the lateral forces. Therefore, we introduce the concept of a wall pier, which group these separate walls together to resist the lateral loads. For our example shear band, it will be grouped into three wall piers, and wall-29 and wall-18 are grouped as pier 2.

Step 2. Check the calculated length of the pier

According to the AWC SDPWS, the individual wall segment with aspect ratio larger than 3.5 shall not be considered as a shear wall, and a segment with aspect ratio larger than 2 would take shear capacity reduction. The C_asp value in the table below is therefore introduced to account for this adjustment. C_asp takes value of 0 when the pier's aspect ratio exceeds 3.5 and takes value of 1 when the aspect ratio is less than 2. We then obtain the calculated length of each pier by multiplying C_asp with the actual length.

Step 3. Distribute the shear band force into piers

For simplicity and to avoid iterations, we assume the shear capacities of shear walls in the same shear band are the same, so the lateral loads are evenly distributed proportional to each pier's calculated length.

For example, the calculated length of pier 1, 2, and 3 in our example shear band are 20.33', 12.63' and 0', and the total seismic load for this shear band is 4492 lbs. Therefore, the seismic load for pier 2 is 4797 × 12.63 / (20.33 + 12.63 + 0) = 1838 lbs.

Furthermore, the load distributed to each pier is assumed to be resisted by the end posts. For example, the end posts of pier 2 are posts 39 and 5, and each takes half of the load 919 lbs. This load is reflected by the horizontal reactions at the posts' bottoms.

Step 4. Calculate the TC couple on pier ends

The overturning moment of each wall pier equals v × h, where v is the lateral load the pier takes and h is the height of the pier. This overturning moment is resisted by the tension and compression couple occur at pier ends, assuming the studs in the middle do not have any contribution. In addition, the resisting moment of dead loads is not considered, which would yield a more conservative result in our calculations.

The tension and compression couple T = C = v × h / L, where L is the actual length of the pier. For example, for pier 2, the seismic load it takes is 1838 lbs, and the tension and compression on pier ends are 1838 × 10 / 12.63 = 1456 lbs. These loads are reflected by the vertical reactions at the posts' bottoms.

Both the horizontal and vertical reactions form the demands of the end posts.

Step 5. Calculate the shear flow for the pier and determine sheathing

The shear demand for the wall pier equals v/L. For example, for pier 2, the seismic load it takes is 1838 lbs, so the shear for the pier = 1838 / 12.63 = 146 plf.

Therefore, the sheathing for the pier, including walls 29 and 18, is designed to be S1_5/16_6d@6, whose capacity is 200 plf. The DCR for these two walls are 0.73. Here, "S1_5/16_6d@6" means

We follow AWC SDPWS Table 4.3A to obtain the shear capacity.

C6. Shear Band Design with Force Transfer

The above section discusses shear band design for the top floor of the building, where we do not need to consider force transfer from the above. When we progress down to other floors, however, we have to consider the impact that the above floor is exerting.

In this case, we will run calculations in the following steps, using "f1-shearband-2-x" as an example:

Step 1. Calculate the total horizontal force

We assume the Rx from the upper posts can be carried to the lower floor through proper connections (e.g. HDU hold-downs or MST straps) and convert the Rx from the upper floor posts into the horizontal loads on the lower floor.

For instance, the Rx for post 51 on Floor 2 is -1479 lbs, and post 51 is located right on post 78 of Floor 1. Therefore, there should be a horizontal force of 1479 lbs on top of post 78 on Floor 1.

The total horizontal force for the shear band equals the sum of all loads from Floor 2 posts and the loads distributed from the tributary area. For shear band "f1-shearband-2-x", the sum of all loads from Floor 2 posts is 1479 + 1479 + 919 + 919 = 4797 lbs and the loads distributed is 4255 lbs. Therefore, the total horizontal force is 9052 lbs.

Step 2. Follow the same procedure as mentioned before

As an example, the shear load on pier 4 = 9052 × 16.08 / (3.08 + 4.06 + 16.08 + 0) = 6270 lbs.

Shear demand = 6270 / 160.8 = 390 plf.

Therefore, the sheathing is designed as S1_15/32_8d@4, and the corresponding DCR = 390/430 = 0.91.

The end posts' Ry: T = C = 6270 × 10 / 16.08 = 3898 lbs.

Step 3. Calculate the posts' demands from upper floor

Similar to Step 1, Ry from Floor 2 posts shall be converted into vertical loads on Floor 1. In doing so, there are two scenarios:

1. The upper floor post sits on a post on the lower floor.

2. The upper floor post sits on a beam on the lower floor.

For Case 1, the load is assumed to be carried directly by the lower floor post. As an example, post 39 on Floor 2 sits right on post 55 on Floor 1, and Ry for post 39 is -1756 lbs. The load is carried downward to post 55 directly.

For Case 2, the beam is assumed to be simply supported, which means it rests on two supports and is free to move horizontally. Therefore, the load is distributed to the posts on both ends of the beam. For example, post 40 on Floor 2 sits on beam 28 of Floor 1, and loads passed from post 40 onto beam 28 is supported by post 50 of Floor 1: 1456 × 16.95 / (16.92 + 3.25) = 1221 lbs.

Step 4. Calculate the total demand for posts

Add loads from Steps 2 and 3 together to get the total demands for posts.

For instance, the total demand for post 50 on Floor 1 P = -3726 + 1221 = -2505 lbs. The negative value means that the post is in tension under seismic load.

As we demonstrates calculations that derive the lateral system design, in the next article, which will be the last of this series, we will discuss designs for the gravity systems, as well as posts, which are impacted by both lateral and gravity forces.

About the Authors

Robin Li, EIT is the Co-founder and COO of Genia and now leads product management. After graduating from University of British Columbia, Robin started off his career at Arup as a certified structural engineer, where he designed structures for a high-rise casino hotel in Macaw. Later, he returned to Canada and designed 100+ low-rise and mid-rise structures, including high-end custom homes in timber. You can find Robin on Linkedin or email him at robin@genia.design.

Calvin Zheng, EIT joined Genia in 2024 as a product manager. He holds a master’s degree in structural engineering from UCLA and has 5 years of experience designing structures in Los Angeles, first at JCE Structural Engineering Group and later at KPFF.

In this article, Genia Co-founder Robin Li will give us a walkthrough of one of the recommended design options that we present to the client. Our deliverables consist of a structural drawing file in CAD format, as well as a calculation sheet showing code compliance checks and structural performance analyses.

User Interface

If you haven't seen our product demo before, here is a short video capturing the user interaction of creating a project in our Generative Design copilot.

Users can specify the location and upload the architectural drawings in CAD format, and our systems can run the design generation and provide the generated results usually in just a minute or two.

Each of the generated design options will contain a structural drawing file in CAD format, as well as a detailed calculation sheet in PDF. Let's walk through one of the generated options for the sample project in Medina, WA, shall we?

Structural Drawing

Here is the structural drawing in CAD that we generate for the sample project.

In the file, we place the structural plan of the three floors side by side, along with a legend block on the left. For all floors, the new structural design is placed directly on top of the original architectural drawing, whose elements are dimmed with a light gray color. Each floor is surrounded by a set of grid lines in cyan blue color to help with placement anchoring across floors.

Level 2

On Level 2, the three segments of the roof are first supported by three rafters. We then add beams, shear walls and posts to form the structural systems that would resist both the gravity and lateral systems. All beams, rafters and shear walls are annotated and numbered accordingly and in the same fashion as in the calculation sheet.

Level 1

For Level 1, joists are used to support the top floor. Opening areas like the living room and stairs are left uncovered. Joists are separated and supported by walls and beams. Extra beams are placed to support the gravity loading passed down from the top floor, for instance from posts, as well as forming the lateral system with shear walls given this property is sitting in a seismic dominant area.

Basement

For the Basement, the exterior walls form the shear wall system for lateral stability. Joists and beams are placed to support the above floors. A concrete strip footing is designed as the foundation system. (Note that in this sample project we didn't receive the geo-tech report at design time, so we had to make some basic assumptions about the soil condition.)

Calculation Sheet

The Calculation Sheet can be found here.

In the video below, Robin will walk you through each section of the calculation sheet and give you a high-level summary of what you can expect for every design option that we generate.

Now that we've had a high-level overview of the design methodology and outputs, in the next article of the series we will dive deep into the design details of the lateral system for the building. This would cover how we analyze force requirements from wind and seismic loads and how we translate these requirements into shear wall details.

About the Authors

Robin Li is the Co-founder and COO of Genia and now leads product management. After graduating from University of British Columbia, Robin started off his career at Arup as a certified structural engineer, where he designed structures for a high-rise casino hotel in Macaw. Later, he returned to Canada and designed 100+ low-rise and mid-rise structures, including high-end custom homes in timber. You can find Robin on Linkedin or email him at robin@genia.design.

We know that for a structural engineer, trust isn't given; it's earned through rigorous, verifiable calculations. Our goal is to transparently detail the engineering principles and computational processes behind our Generative Design copilot.

Project Setup

The project that we will work together is a single-family house located in Medina, WA with zipcode 98039. The property owner wanted to build a new house on the land that they recently acquired, and the architects designing this property approached us for structural design.

Side views

The property consists of two floors above the ground and one basement, which also contains a garage. Here are some rendered images of the side views of the property.

Floor plans

The Basement is dominated by a four-car garage with a concrete slab base. Adjacent to the garage is a media room. The layout also includes a mudroom, a laundry room with under-stair storage, and a central hallway. Wellness amenities consist of a sauna and a bath, complemented by a dedicated wine storage room. An area for mechanical, electrical, and plumbing systems, including a furnace, is designated, with a crawl space noted above a portion of this level. Stairs provide access to other floors, and perimeter details suggest a below-grade construction.

On Level 1, the main entry opens into a foyer, which provides access to a nearby office and powder room. A central hallway extends from the foyer, leading to two bedrooms. One bedroom features an en-suite bathroom and a walk-in closet, while the second bedroom is situated near a separate full bathroom. The primary living zone is a spacious, open-concept area that integrates the living room, dining space, and kitchen, the latter being supplemented by a pantry. A dedicated laundry room is also included. Stairs located near the entrance indicate access to additional levels within the structure.

Level 2 features a large master bedroom suite complete with an en-suite bath and a spacious walk-in closet. Two additional bedrooms are present: one has a private bath and a balcony, while the other is located near a separate full bathroom. A central hallway connects these spaces and leads to a laundry room and a wet bar. Part of Level 2 will be open to the living room on the floor below. Stairs provide access to and from this level.

The roof is made of three sections of flat roofs at different elevations. Some sections of the room also have multiple roof windows for light.

We receive the architectural drawings in both AutoCAD and PDF formats.

Design Methodology

When Genia Structural CoPilot receives an architectural drawing, it will first parse the CAD file, recognizes key architectural elements relevant to structural design, generates structural layout options, perform analyses on structural stability of each, and eventually recommends top 3 design options balancing structural stability, cost, constructibility and sustainability.

Parse Architectural Drawings

Architectural drawings are typically well-organized but can be messy at times. We've often been asked by our clients what assumptions we make about the architectural drawings. Do the drawings need to follow a specific naming fashion? Do they need to be separated by floors? Do entities need to be put on separate layers?

Well, we realize that putting a strong requirement on drawings, while improving recognition accuracy at margin, kind of defeats the purpose if someone has to spend hours cleaning the drawing before being able to use our product.

Therefore, we only make two minimum assumptions about the architectural drawing and develop a proprietary model that is robust enough to handle the rest of the edge cases. These two assumptions are:

1. Architectural drawings need to be well-layered, which means entities like walls, windows, doors and roofs can be found in separate sets of layers. We rely on layer names as additional cues but do not require a specific naming fashion.

2. Architectural drawings need to be well-formed. As an extreme example, we've seen a cupboard attached to a wall, and the interior perimeter line of the wall was omitted and borrowed from the cupboard. In such case, we will NOT be able to reinstall the missing wall line here and will result in a non-enclosed wall element, leading to an error in our parsing stage.

When we parse an architectural drawing, we look for elements like walls (in particular, structural walls), windows, doors, roof line, opening areas, and decks. We also recognize areas that need support of joists and trusses. We then feed this parsed architecture into our generative design pipeline.

Structural Layout Options

Once the generative network receives the parsed architecture, it explores many different layout options.

The generative pipeline follows a similar approach as human engineers: It designs the gravity system from the top to the bottom, first placing trusses and/or rafters to support the roof and then designing the structure one level below by taking the roof load distribution into consideration. It iterates in such fashion for every floor until the whole building design is complete.

For the lateral system, we look at the building holistically across floors and try to identify common "shear bands" (aka "shear line" or "braced wall band") in both x and y directions. We then place necessary structural elements to complete the design within each shear band.

Code Compliance & Structural Analysis

For each one of the generated design options, we evaluates its structural performance and building code compliance, filtering those options that meet the minimum requirements.

Currently we support building codes in the United States and Canada. For the US, we follow the International Building Code (IBC), with the numerical requirements coming from the ASCE 7 Hazard Tool API. By specifying the location of the property, we obtain the building code requirements covering seismic, snow, rain, and wind. For Canada, we support the National Building Code of Canada (NBCC). Both IBC and NBCC are performance-based.

When we analyze structural performances of the generated design, we first calculate the force requirements for wind and seismic, based on the exterior contour of the property. We then evaluate the structural performance of the designed lateral and gravity systems, both force demands and capacity by selecting the best materials in our product catalog to meet the force requirements. We will cover more details in the next three articles.

Design Recommendation

In the end, among those structural design options that pass the minimum building code compliance check, we recommend top 3-5 different structural design options, balancing:

• Structural stability—How much buffer the designed structure has.

• Cost—How much our designed structure will cost. This is only a directional guide, as we are not yet integrated with the local distributor network.

• Constructibility—The fewer number of SKUs we use in this design, the easier the construction could be.

• Sustainability—The less material we use in volume, the more sustainable the building is.

Typically, we will recommend at least one option that is cheapest with the least material use and cost, one other option that has the most extra buffer for structural stability and inevitably uses more material and is more expensive, and a few options in between.

For every recommended design option, we will provide the structural drawing in CAD format, as well as a calculation sheet in PDF that contains all structural analysis details.

In the next article, Genia Co-founder Robin Li will give you a walkthrough of one of the generated structural design for this sample project in Medina, WA.

About the Authors

Robin Li is the Co-founder and COO of Genia and now leads product management. After graduating from University of British Columbia, Robin started off his career at Arup as a certified structural engineer, where he designed structures for a high-rise casino hotel in Macaw. Later, he returned to Canada and designed 100+ low-rise and mid-rise structures, including high-end custom homes in timber. You can find Robin on Linkedin or email him at robin@genia.design.

Calvin Zheng joined Genia in 2024 as a product manager. He holds a master’s degree in structural engineering from UCLA and has 5 years of experience designing structures in Los Angeles, first at JCE Structural Engineering Group and later at KPFF.

15 engineers. 18 months. Thousands of spreadsheets. 750,000 manual calculations.

That was the reality for my co-founder, Robin, working on the Grand Lisboa Palace hotel early in his career at ARUP. It highlights the incredible amount of repetitive grind involved in bringing a high-rise structure to life.

He saw the same pattern throughout his career: smart engineers bogged down with endless calculations, drafting and checking, stealing time away from complex problem-solving and innovative design.

This shared frustration is why we started Genia.

When Robin and I met at our previous startup, his stories resonated deeply with me. My background is in product innovation, and construction is a familiar territory.

My dad runs a geotechnical consultancy, and growing up, I saw firsthand the challenges his team faced. They wrestled with the same slow, manual design processes: painstakingly translating field data into logs, manually drafting cross-sections, performing repetitive calculations for slope stability or foundation bearing capacity by hand or in cumbersome spreadsheets, and constantly double-checking everything to avoid errors that could lead to overly conservative designs or worse. It felt like a clear opportunity for a smarter approach, not just in structural, but across engineering disciplines.

The Challenge We All Share

Honestly, Robin's and my dad's experiences aren't isolated, are they?

We invest billions globally in sophisticated analysis software, but let's face it, 60% of our design work is still done manually.

It’s not just slow; it’s stressful. We all know the pressures: tight deadlines, complex coordination, constant checking.

Doing things manually inevitably opens the door for mistakes. And when roughly 40% of drawing submissions are initially rejected because of simple errors? That means real money wasted on delays, blown budgets, and significant frustration for everyone involved.

It’s pretty clear we’re spending too much valuable engineering time on tedious tasks that technology could handle.

So, we started asking: could Generative AI actually help here? Not just automate, but perhaps intelligently generate and validate the repetitive parts, freeing us up for the core engineering challenges?

Validating the Need & Building the Solution

We didn't want to operate on assumptions, so we talked to people. A lot of people. Over 200 folks across the industry – engineers doing the day-to-day work, principals managing teams, developers funding projects, even the reviewers working within city governments checking plans.

The feedback was consistent and clear: yes, this is a real pain point, and yes, better tools are needed. That confirmation gave us the push to actually build Genia.

We brought together a team with deep experience in both structural engineering and AI, plus the know-how to build reliable software. We all strongly believe engineers deserve better tools. This isn't just another venture for us; we committed fully, leaving stable jobs and bootstrapping the company initially because we are serious about solving this problem.

What We Built: The Genia Structural CoPilot

Let’s first begin with an analogy. If we look across graphic design tools, largely we can put them into three generations.

• The first generation is represented by Adobe Photoshop, which contains a lot of features to get the work done. Skilled designers can spend hours coming up with an awesome design, but the tool itself requires a steep learning curve.

• The second generation is represented by Figma and Canva. These tools are a lot more tailored and streamlined, and users can navigate through their functions pretty easily. While professional designers can still build up great designs, the tools themselves are more approachable to everyday users as well.

• Lastly, with the recent development of Generative AI, we’re seeing platforms like Midjourney, where AI does most of the manual work, and human users can give instructions and improve on what AI generates. The main difference here is that human is now doing more of design review and feedback than the actual drawing.

The same framework also holds for engineering design. Three to four decades ago, the industry witnessed the movement to computer-aided design (CAD) and later to building information models (BIM). Yet, both AutoCAD and Revit would be classified as the first generation design tool because of their complex functions and steep learning curve in order to properly navigate.

The engineering design industry does NOT have a second generation tool with simpler UX, let along a third generation AI-native design platform.

And that is why we created Genia Structural CoPilot to be a powerful assistant for structural engineers.

Genia Structural CoPilot takes architectural drawings as input, generated hundreds design options with AI, evaluates structural performance and code compliance of each option, recommends top design options with structural drawings and calculation sheets, and selects the best materials in our catalog to meet the force requirement.

Tasks that usually take weeks or months of drafting can now be generated, ready for your expert review and refinement, in just hours.

But it's not just about speed. The engineers using it already are seeing designs come together up to 10x faster, certainly, but they're also experiencing fewer errors and finding opportunities for more efficient material use, which benefits both the project budget and sustainability goals.

Join Our Journey

Look, we started Genia because we believe in engineers. We want to build tools that handle the necessary but time-consuming tasks so you can focus your skills where they matter most.

We envision a future where technology enhances our jobs, letting us tackle more interesting problems, design more creatively, and build smarter, safer structures.

If you're an engineer feeling these pressures, check out what Genia can do.

We’d love to hear your own experiences and thoughts in the comments, too!