How to Construct a Home That's Resilient in Coastal Flooding Conditions

Did you know that globally, we lose an entire football field of wetland every 100 minutes? Due to an abundance of severe weather, prolonged precipitation, and the steadily increasing global warming temperatures, Louisiana's wetlands are being swallowed up at a drastic rate. Multiple organizations, notably the Coalition to Restore Coastal Louisiana (which I am a member of), aim to spread awareness for the current erosion of the environment, yet despite efforts of reversing the damage, new engineering lengths have been taken to combat the phenomenon of significant coastal flooding.

In this Instructable, I detail a solution for the current environmental struggles around coastal Louisiana, specifically about the flooding in areas where people live. A new kind of house design, strongly inspired by the current Base Flood Elevation standards, can combat the issue of the terrible weather Louisiana currently endures and can minimize the total damage of the hazardous climate. This house will be present in the New Orleans coastal region, where such houses are in danger to these climates, and are accessible by normal road infrastructure.

I have utilized my understanding of structural engineering from 10th grade in this Make it Resilient 2024 Competition, with consideration towards material stress/strain, resilience, electrical engineering and physics. I have outsourced to an engineering student in college to provide some ideas with this, and one of my engineering professors early in the design process. I am a junior myself, and I enjoy CAD design, which is why I thought this competition could be perfect for me to try and portray my skills to a larger audience.

Supplies

For this Contest:

Autodesk Fusion360

Foam Board

Glue Gun

Exacto Knife

The Real Home:

Cypress

Concrete

PVC Pipe (Plumbing)

Fiberglass (Tanks)

Electrical system, including Solar Panels

Galvanized Steel (Ventilation)

Drywall (Inner Insulation)

Rockwool Insulation

Shingles (Roof)

Note: all resources are specifically chosen because they are Louisiana-available, minimizing transportation and deforestation costs.

Step 1: Brainstorm and Illustrate Your Elevated Home

After doing some research on BFE designs, I quickly sketched a fast mock-up of a home. Utilizing the knowledge that wood with an upright position is less prone to collapsing than wood with a flat position, the wooden beams are meant to be placed upright for more resistance against breaking.

Some estimations of measurements are also written above. The standing lumber beam lengths are respectably 1' by 4', and there is a ten foot distance between each beam. A floor plan isn't necessary yet, but you may sketch that too, if you'd like. I generally saved the floor plan sketch post-Step 2.

I had also done some prior research with my engineering professor with an architectural landscaping background, who gave me some criticisms and also point-outs for building a home that would withstand severe flooding weather. He also helped me with ideas on house systems that could be resilient to hurricanes, which Louisiana is abundant with, and materials that are local in Louisiana and could save money and trees.

Step 2: Modeling the Base + Stairs in Fusion

At this step, you want to have an Autodesk Fusion account, and if you don't have one, you can create one here. I will be using a school-sponsored account free of charge. Fusion is a strong resource to use when engineering so that you can simulate your final project in a CAD space, and catch errors early before constructing the final product. Fusion also gives you a cumulative summary of the items you utilize, pricing your project needs later.

A general strong rule about BFE is that the protrusion into the soil must be deep, so that in case of soil expansion and collapse in water, the house doesn't immediately de-stabilize. I used local lumber in Louisiana to contribute less to pollution, cypress, which would help save a lot of money using local resources. When building the base, you will also need to add structural support if your under-floor section is going to have open spaces, such as reinforcing your house with truss support. Though I hadn't used support for mine this early in the process because I wanted to do the stress calculations post-completion of the skeletal structure of the home, it is still essential to plot where the protrusions will be below the base floor, and dig out the soil in advance of construction. Also, when making the subfloor to the main floor of the house, it is important to remember to place wood vertically for maximum resistance to weight so that your floor won't collapse.

After this, I added a staircase that would be supported at both sides with some more protrusions into the soil. I then finished with a concrete coating, that would enable the house to utilize modern infrastructure. Concrete is also resistant to water, and protects soil with an extra layer.

Step 3: The Floor Plan

Although this idea was mostly free-reign (and also sketched by my friend), this would be your gateway to innovation as well. The usage of where windows will be can contribute to passive insulation, a rather revolutionary and very resource-saving technique where based on how you construct your home, you can strongly minimize costs over a long term period by minimizing the use of electric temperature control.

When designing your floor plan, PLEASE REMEMBER to leave space between the walls. A general safe size of the total wall is around 4 inches, though due to the rough manner of hurricanes and tornadoes in Louisiana, I opted for larger walls at 12 inches. A hefty amount of space is left for electrical work, pipes, and insulation, which will be incredibly essential for the viability of the house.

Step 4: A Second Floor and Roofing

A second floor was entirely optional, however, due to the idea that we don't want our AC to be flooded, I've decided to add a second layer to my home to secure the ventilation. Our entire cooling system and storage will be secured up here, using decorative protruding vents with caps on top of them. This will be detailed later, but for now, it is simply important to make sure to place wood vertically and make sure to calculate with stress-strain equations to see the maximum threshold of what your structure can hold until collapse. Generally, make sure the collapsing weight is much, MUCH higher than the weight you need.

When making the roofing, be considerate of which kind of roofing will contribute to the most natural water flow possible. Layered roofing that is made of ridges upon ridges is generally preferred for this, as water spills down the sides of the roofing without reaching the building and it is also guided to the gutters that prevent the water from disturbing the walls. Layered roofing is also easily recyclable, cheap, can handle high roof traffic, and has high durability.

After this step, your skeletal home is done! Before finalizing your structure, it is time to add some other qualities to make your house habitable.

Step 5: Electrical System in the Floods

Louisiana is one of the hottest states in the United States. Sunlight is stronger, and it is highly recommended you wear sunscreen daily in this state due to the strength. Because of this, I've decided to use a dominant source of power-saving energy in Louisiana, which is solar panels.

When making solar panels, you want to also consider an angle to the panels in order to maximize energy taken in from the sun. Commercial solar panels use a system that angles the panel towards the sun at all times, but for homes, it is generally acceptable to let your solar panels be flat if the sun is overhead. Solar panels must be attached to an adapter, which is then funneled through a charge controller that regulates where the generated power is headed. Some of this power will go to a separate chargeable battery, which can also be used in crisis, but is mostly used to allocate extra energy that would otherwise not be needed. DC current will then go into an inverter, which will emit AC current to house appliances, such as fans, televisions, fridges, and artificial lighting.

Since this house is on the grid, some homeowners that use solar power also opt to sell some of their excess energy to the electrical company for excess profit. This is an efficient method of generating money over time, using the surplus for a stable income. When the electrical company is cut off, using the solar batteries that have been storing excess energy can be opted in as the DC current at a respectable ampere.

Step 6: Plumbing, Greywater and Rainwater Adaptations

A casual plumbing system with PVC pipe would be perfect for any home. Louisiana's environment never reaches such extreme temperatures that can seriously amalgamate the shape of expanding pipes, and pipe freezing is generally easily combatted with lightly running water in the winter. However, instead of settling for this solution, a more innovative approach can be taken.

Rainwater re-usage is a new, innovative method of plumbing systems that enables rain from weather to be recycled into freshwater for home systems like showering, sinks and drinking water. Using a siphon inside of the tank, water can be effectively funneled into the building, resulting saving money from the water bill.

Not only can we use this method, but we can also use greywater recycling. After fresh water is used for our benefit, newly dirtied water is called greywater, and is usually polluted out into the rivers with various pathogens and inhospitable qualities, which is a HUGE problem for Louisiana's coast. Wildlife is frequently victim to the greywater from our homes, so to minimize this, a greywater recycling system has also been added. Using two filtering layers that can separate the toxic and harmful qualities from the used water, we can use this de-poisoned water to send to the sewage system, or direct to gardens around the home.

Step 7: Passive Insulation, a Cost-efficient Solution

For the home insulation, the inner walls should be made of drywall to prevent horrible weather offenses from harming inhabitants severely in the case of flying large objects. However, we are going to use passive insulation in order to defend this home from severe temperatures. Rockwool is an efficient resource that defends strongly against water damage and provides amazing soundproofing, so we are going to use it for our insulation. This passive insulation works significantly better than normal insulation, and is very cost-efficient, as rockwool tends to last the lifetime of the building.

What can also provide passive insulation is window shading. Shading in front of the windows with blinds can minimize the effect of intense sunlight, cooling the home naturally. Although this has been a rather common method of insulation that is installed in nearly every home, it is still highly efficient and necessary.

There are also gates in front of the doorway. These gates are able to be closed incase of flooding above the BFE level, which can prevent floodwater from leaking into the house in worst-case scenario. Various buildings in New Orleans have these installed which are closer to the flood level, preventing worse water damage.

Step 8: Ventilation

The second floor built for the home comes into use. Because ACs are generally located outdoors, this comes in with the obstacle that flooding is a major issue, so the placement of the AC has to be compromised. This is where the second floor is made necessary.

With the AC inside of the building, this can avoid the issue of being afraid of having unclean air or straight up flooding your AC during bad weather. Ventilation systems tend to usually work by letting in fresh air in one end and then expending used air from another end, with some natural ventilation from opening windows, opening doors, et cetera. A fan used to circulate the air inside of the pipe can direct where the air can go, with refridgerant included to absorb heat from the environmental air and purify some properties.

Step 9: Final Steps, Decoration

For a house to be appealingly habitable, it should also look good. I made a few painting decisions and extra bordering to hide some of the internal structure that upholds the house, and I decided against the use of crossing diagonals because my home already stood normally without collapsing. I also added a railing for my stairs, including the other side. Finally, I glassed in the windows and filled in the doors, Including making the emergency exit door in the back in case of a fire scenario. A rudimentary ladder can provide for a fast escape from the building.

That's it for the CAD Design!

Step 10: Prototyping: the Base

After the CAD Design was finished, I decided to recreate the house as a very, very simple prototype. The scale was a 1ft:1cm ratio. I decided to test the base structure of the house and its survivability, to see if my physical calculations were correct with the endurance of the building. So far, with the first floor done, it seemed to work out.

I had to also simulate flood conditions with my prototype. Since my house was made of foam, a buoyant material, I had to secure its edges down with shampoo bottles, before filming it getting moderately flooded in my bathtub. The video shows the results. Because the house hadn't been destroyed and didn't collapse, I concluded this test was a success, and moved on to constructing the second floor.

Step 11: Prototyping: the Roof

Building the second floor was not any more challenging. By building the second floor without annexing it to the first floor immediately, the full construction was much simpler and saved a lot of struggle and time. The finished product securely stood on its supports, which guarantees its structural stability.

Afterwards, I put the house through the bathtub test again, but this time I turned on the shower to simulate heavy rain. Since flooding was already tested, I didn't find it necessary to heavily flood the base a second time. The house survived the rain test, with no complications whatsoever.

An unexpected bonus was that due to the angled roof, rain jumped off at an angle which prevented the drenching of the wall. Although this was probably expected, I hadn't dreamed of the opportunity, so it miraculously worked out.

Step 12: Conclusion

This project had taken me around 20 hours in total, and I am mostly happy about both the CAD and prototype result. This was a good use of my free time and undoubtedly a fun project, though it required a lot of dedication and persistence with mistakes.

Benefits of the house include renewable energy, affordable water systems that don't pollute Louisiana's environment, natural insulation and raised ventilation. Living in this extreme environment would be preferable compared to a normal home because of such benefits, though the inhabitant's decision of where to reside is entirely up to the inhabitant.

Thank you for reading, and enjoy your new flooding-resistant home!