The housing crisis has shown the challenges and almost impossibility of building high quality, affordable houses. How is this approach different? Here are a few key design principles that a Reimagined Home differs from a typical home:
Design the house to be simplier, smaller and easier to build than a typical house
Use natural materials, outdoor spaces and a rooftop deck to connect the house to the outdoors
Simplify the wall and roof assemblies by using foam and wire prefab panels, with concrete applied in the field to both sides
Choose materials and products that are easy to install and easy to inspect the installation quality
Keep plumbing, electrical and HVAC accessible to simplify future repairs and upgrades
Reduce or eliminate the use of subcontractors
The analysis
It will take more than incremental improvements to simultaneously improve home affordability, resiliency and durability. It requires some bigger changes. Here are the biggest changes, and the analysis behind the change.
Wood is the Problem
Any builder will tell you that water is the biggest threat to homes. Leaks, mold, rot and other water problems cause far more damage to homes than natural disasters. But water isn’t the problem. The problem is building with a material so vulnerable to water damage (wood). A large part of the complexity and cost of construction is related to protecting wood from water. Eliminate wood and building houses becomes easier and requires less skill. For example, proper installation of windows is complicated and requires high skill. Layers of protection are applied to the window opening, with the goal of preventing water from getting into the wall assembly. And the stakes are high— if water gets into the wall, serious damage can occur before anyone knows there’s a problem. Compare this to a wall assembly using water resistant concrete and foam. Even if water gets in from the exterior, it can’t go into the wall assembly. The water would go to the interior of the house where it would be quickly noticed. A simple repair, such as applying more caulking, can be done before any serious damage occurs. A less experienced worker can install windows because the process is simpler and the cost of mistakes is lower.
Eliminate Subcontractors
According to the National Association of Home Builders, a typical home requires 22 different types of subcontractors. (reference) Subcontractors are such a key part of construction that we typically consider them the only way to build. But the concept of the trades is an old idea, which has not been updated in more than 100 years. What other industry has workers who are so narrowly focused on a specific skill? Take the example of an auto mechanic. This is skilled work, with potentially deadly results if the work is done incorrectly. An auto mechanic uses diagnostic, computer, electrical, plumbing and mechanical assembly skills every day. Why do we expect auto mechanics to have a wide variety of skills, but don’t expect the same from construction workers? Why in construction is it impossible for an electrician to also install HVAC heat pumps, or for a sheetrock person to also install tile? Of course it’s not. In California and many other states, General Contractors can perform all construction tasks for building a home, and remodelers routinely handle many trades.
The case for using subcontractors with narrowly focused skills is related to experience. The thinking goes that, for example, a plumber encounters unusual problems and situations over years, and can solve new problems better and faster based on the experience only doing plumbing. But does this apply to new construction? The design work
It’s important to note the skill difference required for new construction compared to repairs. New construction is much easier because the drawings show the design, and the building code dictates allowed assembly methods. Repairing an old house is much harder, with potentially decades of changes, obsolete components, and inaccessable plumbing and wiring. Troubleshooting a wiring grounding problem problem in an old house is much tougher than home run wiring for a new house.
There have been huge improvements in some building materials that have reduced the skills required for almost all subcontractors. Most home plumbing is done with PEX tubing and easy fittings instead of soldering copper pipe. Rectified porcelain tile is much easier to install than natural stone, WAGO connectors are safer and easier than wire nuts for electrical connections, paint is better, adhesives are better, LED lights are safer and easier to install, duct free heat pumps are easier than ducting, and the list goes on and on. By properly choosing the right building materials, it’s possible to reduce the skill and experience needed to do quality work.