Summary
Cutting costs is important when building an ADU, but cutting too much in the wrong places can cost you more later. In this post, we shares 7 upgrades we recommends to almost every client: smart, durable improvements that protect your budget long term and make your ADU more comfortable, reliable, and hassle-free for years to come.
In our previous blogpost, we talked about the biggest cost drivers when building an ADU and how smart planning can help you avoid unnecessary expenses. But after you’ve cut the right corners and kept your budget in check where it makes sense, there’s one piece of advice I always give my clients:
Sometimes, the best way to save money is actually to spend a little more upfront on the right things.
Think of it this way: you’re not just building something for today. You’re building a space you’ll live in, rent out, or share with family for years to come. If you cut corners on quality now, you’re almost guaranteed to pay for it later, whether it’s repairs, replacements, or just frustration with things that don’t work the way they should.
That’s why when I sit down with homeowners, I don’t just talk about cutting costs. I also walk them through the smart investments that are actually worth spending a little extra on. These are things that improve durability, comfort, and long-term value, and help you avoid those costly regrets a year or two down the line.
Here are 7 areas where, in our years of experience, it’s well worth putting your money.
1️⃣ Solid-Core Doors
Interior doors might seem like a small detail when you’re designing your ADU, but trust me, this is one of those places where a little extra upfront cost makes a huge difference in how the space actually feels to live in.
The cheaper, hollow-core doors you often see in new construction feel flimsy, sound hollow when you close them, and do very little to block noise between rooms. Over time, they tend to warp, rattle, and simply don’t hold up with daily use, especially in rentals or multi-generational setups where people are opening and closing doors constantly.
Solid-core doors feel heavier, sturdier, and do a much better job blocking sound. The privacy is noticeable, especially in smaller ADUs where bedrooms and bathrooms are close together. That added weight and quality also help them last longer without sagging or wearing out.
And it’s not just the doors themselves. While you’re at it, you want to pair them with good quality hardware too:
- Solid hinges that don’t loosen after a year
- Well-made knobs and handles that feel solid in your hand and don’t get loose or wobbly over time
- Smooth-closing latches that avoid that annoying “slam” when doors close
The best part? We’re not talking huge dollars here. For most ADUs, spending maybe an extra $1,500 to $2,000 across the entire project gives you doors and hardware that feel high-end every single time you use them. It also helps make the entire ADU feel more solid, quiet, and well-built for years to come.
2️⃣ Quiet Drain Pipes
One upgrade a lot of people don’t realize they need until it’s too late is soundproofed drain pipes, especially for two-story ADUs or ADUs attached to the main home.
In a smaller space, you’re often much closer to your plumbing than you would be in a larger house. With standard PVC pipes, you hear every flush, shower, and sink drain, sometimes even from across the unit. People often don’t think about it until they move in, then suddenly realize how disruptive that water noise can be, especially at night.
The solution is simple: invest in cast-iron or quiet-rated drain pipes for key areas like upstairs bathrooms or shared walls. It’s a small upgrade during framing but makes a big difference in comfort, especially for long-term living or rental units where you want your ADU to feel like a private, quiet space.
3️⃣ Quality Garbage Disposal
You’d be surprised how often I see homeowners regret going cheap on something as simple as a garbage disposal.
The basic, entry-level models might save you a hundred bucks at the start. But they tend to jam up, struggle with larger food scraps, and burn out after just a couple of years, especially if multiple people are living in the ADU or if it’s being used as a rental. When they fail, it usually means calling a plumber, dealing with water backups, or replacing the whole unit sooner than you’d like.
Spending a little more upfront for a better-quality disposal gives you stronger grinding power, smoother operation, fewer jams, and most importantly, fewer plumbing headaches down the road. In a smaller ADU where every system gets a lot of daily use, simple upgrades like this can save you from unnecessary maintenance calls, frustrated tenants, or out-of-pocket repair costs later.
4️⃣ Interior Insulation
Most people understand the value of exterior insulation for energy efficiency, but where a lot of homeowners miss an opportunity is inside the house: interior wall insulation.
I always recommend adding insulation between rooms, especially between bedrooms, bathrooms, and shared walls if the ADU is attached to your main home. It’s a relatively small upfront cost, often just hundreds of dollars, but the payback is huge in terms of comfort and privacy.
This is especially important if your ADU is going to be rented out, used for guests, or become a multi-generational living space. Nobody wants to hear conversations through the walls, toilets flushing upstairs, or someone watching TV late at night.
It’s one of those upgrades that renters will never directly notice, but they’ll feel it. And if you plan to live there yourself, you’ll appreciate it every day.
5️⃣ Heat Pump Water Heaters
As we talked about in the previous post, California’s newer regulations are pushing many homeowners toward heat pump water heaters. While they do come at a higher upfront cost compared to older gas tankless units, they’re one of those upgrades that truly pay off in the long run.
Heat pump models are much more energy-efficient and can help significantly lower monthly utility bills. This matters even more in areas like San Diego where electric rates keep climbing. Many models also pull heat from the air around them, which can even help cool and dehumidify the space they’re installed in.
This is one of those upgrades where yes, you may feel the sting up front. But after a few years of lower energy bills, fewer repairs, and better overall efficiency, most homeowners are glad they made the switch.
6️⃣ Durable, High-Quality Flooring
Flooring is another area where going cheap is almost always a mistake, especially in a compact, high-traffic space like an ADU. The floor is one of the most heavily used surfaces in the entire unit, and low-quality materials just don’t stand up to the daily wear and tear, particularly if the ADU is a rental. Inexpensive laminate flooring might look fine on day one, but it’s notoriously prone to scratching, chipping, and swelling at the seams the moment it gets wet—a disaster waiting to happen in a kitchen or near a bathroom. Similarly, low-grade carpet wears down quickly in pathways, stains easily, and will likely need to be replaced after just a few years of use, creating a cycle of unnecessary expense and hassle.
Spending a little more on a superior material like Luxury Vinyl Plank (LVP) or engineered hardwood is a far smarter investment. LVP is a fantastic choice for ADUs because it’s waterproof, highly scratch-resistant, and does an excellent job mimicking the look of real wood. It’s built to handle tenants, pets, spills, and constant foot traffic without degrading. You’re not just paying for a better-looking floor; you’re paying for durability that prevents you from having to do a costly full-floor replacement every few years. It’s a choice that saves money, avoids tenant disruption, and keeps the ADU looking its best for much longer.
7️⃣ Thoughtful Electrical Planning
One of the most common regrets we hear from homeowners after their ADU is built has to do with something surprisingly simple: outlets and switches. During construction, it’s tempting to just meet the minimum code requirements for electrical outlets to save a few hundred dollars. This is almost always a mistake. The “cheap way” results in a space that’s immediately impractical for modern life. You end up with not enough outlets for chargers, lamps, and kitchen appliances, forcing you to rely on clumsy power strips and extension cords. You might find there’s no outlet where you want to mount a TV, or that the light switch for a room is in an awkward location. Fixing this after the drywall is up is a major hassle, requiring cutting into walls, patching, and repainting. A smart upfront investment is to walk through the framed space and think critically about how you or a tenant will actually live there. We always recommend adding more outlets than you think you need, especially in the kitchen, near the bedside, and in the living area. It’s also wise to:
- Add dedicated circuits for a future EV charger.
- Place outlets in practical locations, like inside a pantry for charging a cordless vacuum or on a kitchen island.
- Install exterior outlets for landscape lighting or patio use.
Spending an extra $500 to $1,000 on thoughtful electrical planning during the rough-in phase is one of the highest-value upgrades you can make. It costs very little upfront but eliminates years of daily frustration, making the ADU far more functional and convenient to live in.
The Bottom Line
At the end of the day, you don’t have to overspend to build a great ADU. But you also don’t want to chase the lowest price at the expense of long-term headaches. Smart spending isn’t about cutting everything. It’s about knowing where those extra dollars will actually save you time, money, and frustration in the years ahead.
And that’s exactly the kind of planning we help homeowners with at Builders Now.
If you’re thinking about an ADU, feel free to reach out anytime. We’re happy to sit down, walk you through the process, and help you build an ADU that holds up both today and years from now.
👉 Contact Builders Now for a free ADU consult.