GridStack: a Step Towards Affordable, Sustainable Living

Hey there! My name is Joshua, and I recently graduated from high school with plans to study aerospace engineering in college. I’ve always been passionate about designing and building things, especially when it comes to solving real-world problems. It’s been a while since I last posted an Instructable, and since then, I’ve become an Autodesk Design and Make Ambassador, which has been an awesome opportunity to grow as a maker and designer. My skills have come a long way—from learning the basics in TinkerCad back in middle school to designing full-scale competitive robots for FRC (FIRST Robotics Competitions) using Fusion 360. When I came across this contest, I knew it was the perfect chance to bring all of that experience together and tackle two big challenges we face today: housing affordability and environmental concerns. I’m excited to share my project, GridStack, which blends creative thinking, modern materials, and eco-friendly design to help build a more accessible and sustainable future.

Materials Needed:

1. Laptop/Computer
2. CAD Software (Would highly recommend Fusion 360 for beginners and professionals! It's quite easy to learn, and the interface is extremely user-friendly)
3. Experience with CAD isn't required; however, it's extremely helpful!
4. Autodesk Account

Optional Materials:

1. A 3D Printer (I used an Ender 3 V2; it's a great starting printer, however, there are better options on the market)

Links to Models:

1. Stacked Assembly
2. Single Module

The United States is currently facing a growing housing affordability crisis, with more and more individuals and families struggling to find safe, reasonably priced homes. Rising property values, labor shortages, expensive materials, and stringent zoning laws have made it particularly challenging to construct accessible housing, especially in urban areas where demand is high. At the same time, we’re also facing serious environmental challenges, including climate change, limited natural resources, and the consequences of rapid, unsustainable development. Traditional construction methods often make these problems worse by leading to high energy use, pollution, and long-term damage to ecosystems. As someone passionate about engineering and sustainability, I believe that thoughtful design and innovation can play a key role in rethinking how we build. By combining affordability with environmentally responsible strategies, we have the chance to create housing solutions that meet today’s needs while protecting our future: building strong, resilient communities that can last for generations.

For my project, I chose a 2.02-acre plot of land at 8105 Bear Creek Drive in the Bear Creek Oaks neighborhood of Austin, TX. I was drawn to this location because it offers the best of both worlds: beautiful natural views and easy access to everything the city has to offer. Sitting on a hilltop with amazing views of the Austin skyline and Hill Country, the site creates the perfect setting for a sustainable housing design. It’s just 15 minutes from downtown, which means it’s close to schools, shopping, and major roads—but still feels peaceful and community-focused. Since the land is currently undeveloped, it gives me the flexibility to bring my modular housing concept, GridStack, to life in a creative and impactful way.

The city of Austin, Texas, is currently facing a serious housing shortage, especially for low- and middle-income residents. With the city’s population growing rapidly and housing prices continuing to rise, the demand for homes has far outpaced the supply. This has led to a steep increase in rent and property costs, making it difficult for many people to afford a place to live. In some areas, such as District 5, there’s a shortage of tens of thousands of housing units needed to meet the needs of residents. While Austin has started addressing the issue through zoning reforms and support for sustainable development, finding the right balance between affordability and environmental responsibility remains a major challenge. However, as a city that embraces innovation, technology, and sustainability, Austin offers an exciting opportunity to explore new housing strategies that not only close the affordability gap but also support long-term environmental health. With the right designs and materials, we can reimagine how housing works: creating smarter, greener communities for the future.

Austin, Texas, has a humid subtropical climate, with long, hot summers and short, mild winters that create real challenges for housing and energy use. In the summer, temperatures often go above 100°F, which puts a huge strain on cooling systems and makes energy efficiency a top priority. On top of that, the city deals with occasional droughts that affect water supplies and local plant life, along with more frequent extreme rainfall events that can lead to flooding. As urban development continues, it's also making the urban heat island effect worse, trapping even more heat in already hot neighborhoods. With climate models showing that temperatures will keep rising, it’s more important than ever to use sustainable building strategies like passive cooling, renewable energy, and water-saving systems. Since Austin is already known for its environmental efforts, it’s a great place to lead the way in combining affordable housing with smart, climate-ready design.

My original concept, called HEXPods, was inspired by the structural efficiency and modular design of honeycombs. The idea was to create hexagon-shaped, stackable pods using 3D-printed concrete shells, with integrated solar panels on the upper faces to generate renewable energy. The design emphasized both space optimization and sustainability, aiming to deliver a compact, flexible solution for urban housing. While the concept showed strong potential, it faced a significant drawback: the unconventional hexagonal interior required custom-built furniture and fittings, which would increase production costs and reduce practicality, especially in large-scale applications. Although the HEXPods design was eventually set aside, the lessons I learned from it directly influenced the creation of GridStack, allowing me to develop a more cost-effective, functional, and sustainable housing solution.

In response to the growing housing affordability crisis and the pressing need for eco-friendly urban development, GridStack presents a smart, scalable solution that blends cost-effective design with practical sustainability. As the second iteration of my affordable housing ideas, this concept builds on lessons learned from earlier prototypes and focuses on simplicity, flexibility, and real-world feasibility. By leveraging modular construction, renewable energy, and efficient land use, GridStack reimagines affordable housing as an environmentally responsible solution to the ever-growing problem of housing affordability. Designed to address both economic and environmental challenges, this innovative approach aims to provide accessible, high-quality living spaces while minimizing the carbon footprint of urban expansion.

Each GridStack module measures 8 feet long, 17 feet wide, and 9 feet tall, creating a compact, efficient structure suited for adaptable living. The layout is open and customizable, giving residents the freedom to arrange their interior space based on individual needs. For transport and quick assembly, the unit is divided into two attachable sections and utilizes a slot-in connection system that simplifies construction while maintaining strength and alignment. Entry design varies depending on floor level: for ground-level modules, an entrance door is seamlessly integrated into the front-facing glass structure; for stacked modules placed on higher floors, access is provided via an external spiral staircase (not pictured), allowing each unit to remain fully independent while preserving space efficiency. With modules stackable for multi-unit configurations, GridStack supports both standalone homes and dense, sustainable communities. While individual modules can be connected side by side to expand single residences, stacked configurations are intended for multi-unit developments, creating compact, community-oriented housing without sacrificing comfort or sustainability.

Cross-laminated timber (CLT) is a modern, engineered wood material made by stacking layers of wooden boards in alternating directions and bonding them with strong adhesives. This method makes CLT incredibly strong and stable, even strong enough to compete with materials like concrete and steel. One of the biggest advantages of using CLT is that it's sustainable; since it’s made from wood, a renewable resource, it naturally stores carbon and reduces the environmental impact of construction. On top of that, CLT panels are lightweight and easy to work with, which makes it possible to build faster and with less waste through prefabrication. By using CLT in the GridStack housing system, I was able to combine structural performance with eco-friendly design, helping make affordable housing more sustainable and efficient for the future.

GridStack incorporates a range of sustainable strategies to create affordable housing that’s practical, efficient, and environmentally conscious. While the structural framework relies on a renewable material, the design goes further by including recyclable aluminum paneling for enhanced durability and long-term waste reduction. Proper insulation is used throughout the module to regulate indoor temperatures, reducing the energy needed for heating and cooling. The flat roof holds adjustable solar panels that capture renewable energy throughout the day, and the structure is carefully arranged to support natural ventilation, allowing fresh air to flow through the space without depending on mechanical systems. The compact layout minimizes land use while maximizing utility, making GridStack a smart solution for both urban infill and community-scale development. Together, these features work to reduce the project’s carbon footprint while delivering a comfortable and adaptable living environment.

The following renders showcase the GridStack housing concept in various stacked configurations, highlighting its modular design, material choices, and sustainable features. Created using Fusion 360, these visuals help bring the project to life by illustrating how each unit fits together and functions.

Materials Used (Render Workspace):

Bamboo Light - Semigloss: Cross-laminated Timber (CLT)

Aluminum - Satin: Outer Paneling, Trim, Solar Panel Supports, Solar Panel Framing

Glass - Frosted: Windows

LED - SMD 5630 - 50lm (White): Lights

Paint - Metallic (Black): Metallic Accents, Appliances

Plastic - Glossy (Black): Appliances

Marble (White): Countertop, Cabinets, Shower

Solar Panel (Custom Material): Solar Panels

To help bring the GridStack concept to life, I built a 1:100 scale physical model showing the full concept (6 modules in a stacked configuration). I simplified the design for easier printing and split each unit into separate parts, which I printed using my Ender 3 V2 with Overture black PLA filament. I used BambuSlicer to prepare the files, and once printed, I assembled the pieces to reflect the real-world slot-in construction approach. To mimic the aluminum paneling from the digital design, I carefully wrapped the exterior in aluminum foil, attaching it with Elmer’s glue and using a sharp razor to trim clean lines and cut out window openings. This was my first time building a physical model of one of my concepts, and while I’m no artist, it was a great hands-on way to visualize how the modules stack and interact in a real setting.

Bringing GridStack to life has been one of the most unique and rewarding projects I’ve ever worked on. From the earliest sketches and ideas to the final stages of development, this project has taken months of hard work, learning, and creative problem-solving. Along the way, I’ve acquired valuable knowledge in sustainable design, modular construction, and the real-world challenges of creating housing that is both affordable and environmentally responsible. I’ve also had the opportunity to acquire new design skills, experiment with various materials, and explore how engineering can be applied to solve real-world problems. This project has shown me how much of a difference innovation and design can make in people’s lives and has deepened my passion for using engineering to create a better future. For me, GridStack isn’t just a project—it’s a step toward rethinking how we build, live, and care for our communities and our planet.

Thanks so much for taking the time to check out my Instructable; it means a lot! I hope it inspires new ideas and sparks conversations about what the future of housing could look like! Have a great day!