Effective Solutions for Noise Reduction in ADUs

Noise might not be the first thing you think about when building or living in an accessory dwelling unit (ADU), but it can quickly become one of the biggest comfort issues. Whether it's traffic from the street, voices from adjacent apartments, or plumbing sounds from the main house, unwanted noise has a way of creeping in. For ADUs located in a busy city like Boston, the soundscape outside your door can affect how restful and usable your space feels.

The good news is that there are smart, reliable ways to tackle noise in these compact living spaces. With the right building choices and materials, sound can be softened or blocked entirely, giving you a quiet place to work, sleep, or relax. Here are some of the most effective strategies to reduce noise that sneaks into or travels through an ADU.

Soundproofing Walls and Ceilings

Walls and ceilings are two of the most common areas where sound enters and moves between rooms. For accessory dwelling units built in tight neighborhoods or close to constant traffic, this makes a real difference. Even a shared wall with a main house can carry unwanted noise unless it's handled the right way.

Here are a few soundproofing methods that make a noticeable difference:

1. Use soundproofing insulation

Fiberglass and mineral wool are great options for absorbing sound vibrations. These materials can be packed snugly into the walls and ceiling of an ADU to soften and reduce the movement of sound.

2. Choose sound-damping drywall

Not all drywall is created equal. Some are made just for blocking sound, using layered materials that stop vibrations from traveling from room to room. Branded versions of these products are available at most building supply stores.

3. Add acoustic panels

These panels break up sound waves and absorb echo. Though often found in recording studios, they work just as well in residential settings, especially if you’re converting a garage or basement space into a living unit.

The goal here is to stop sound before it spreads across the space. If the ADU is being created from an existing structure, like a basement or attic, standard walls usually aren’t enough. Reinforcing them with the right materials can deliver a much quieter and more private result.

Windows and Doors Upgrades

Even if your walls are well-insulated, windows and doors can still let in a surprising amount of sound. Addressing these areas should be a priority in any ADU noise-reduction plan, particularly in a busy city environment.

1. Install double-glazed windows

These windows use two panes of glass with a sealed air space between them. That gap acts as a buffer and helps dampen the flow of sound into the unit. On a heavily used street or alley, this small upgrade can make a noticeable improvement.

2. Add weather stripping

While often used to seal out wind and cold, weather stripping also blocks sound leaks by closing small openings around window and door frames. This simple improvement helps reduce the hum of outside traffic or pedestrian noise.

3. Install solid-core doors

Many basic interior doors are hollow, which means sound passes right through them. Solid-core doors are heavier and much better at containing sound. Installing them on both interior and exterior entrances improves overall quiet.

In many Boston neighborhoods, we’ve seen garage conversions where the owners finish the interior but don’t replace the doors or windows. Even after everything's painted and furnished, the place still feels noisy. Just swapping the doors and sealing the windows has made a huge difference for those homeowners.

Flooring and Underlayment Solutions

Noise doesn’t only travel through walls and air — it also moves through surfaces. Floors without any soft materials underneath can echo footsteps and add a harsh, hollow sound to a small space. The right flooring setup can reduce those noisy distractions.

1. Pick sound-absorbing materials

Carpet remains ideal for absorbing sound, especially on upper levels. If carpet isn’t your style, some laminate and engineered wood options now come with sound-dampening features that can be combined with underlayment.

2. Invest in good underlayment

A quality underlayment pad is placed between the subfloor and the finished flooring. These layers, made from foam or rubber, absorb the shock of foot traffic and help keep sounds from traveling between floors.

3. Place rugs in key areas

If your ADU already has hard floors, area rugs in the living room, hallway, or bedroom help muffle impact noise. Bonus: rugs add warmth and style, making small spaces feel more complete.

During one of our attic conversions in Boston, homeowners chose hardwood for its look. The sound of every footstep echoed below until we laid down an acoustic underlayment and added two large rugs. From that small change, the unit instantly felt quieter and more private.

Strategic Interior Design for Sound Control

Interior choices might not seem like the solution for noise, but they can go a long way toward softening the space and lessening the sound. The way you furnish and decorate your ADU has more impact than you might think.

1. Move larger furniture pieces

Placing bookshelves, wardrobes, or sofas along shared or exterior-facing walls adds thickness and density that blocks noise. These become passive barriers between you and outside sounds.

2. Use bookshelves and curtains as sound blocks

Loaded bookshelves act like padded walls, slowing down sound waves. Thick curtains — especially the blackout kind — help keep outside noise from seeping in through windows. In larger rooms, heavy fabric helps cut down on echo too.

3. Try out white noise machines

These devices fill a room with steady, low-level background sound that masks sudden noise from traffic, conversations, or neighbors. People use them in bedrooms, home offices, or even nurseries to help with sleep and focus.

These changes may seem small, but they work together to create a more peaceful atmosphere. They also offer flexible options if you're not doing major remodeling and still want to reduce noise inside your space.

Creating a Quieter, More Comfortable ADU

Noise is one of those things that sneaks in until you're fully aware of it. Whether you're using your ADU for guests, family, or rentals, a quiet atmosphere makes all the difference. You don’t need to overhaul the structure or invest in expensive changes. You just need a plan with smart, quality materials suited to urban living.

Start by listening and identifying trouble spots. Is the main issue outside traffic? Is interior sound bouncing around due to hard walls and floors? From there, you can decide what blend of upgrades works best for your setup. Some people choose to block things structurally with insulation and drywall, while others layer up with rugs, curtains, and better furniture placement.

In Boston, crafting ADUs that offer calm in a busy place is part of what we do every day. Our experience with local homes and city noise challenges helps guide each build toward comfort. Whether you're planning from scratch or improving what you already have, turning the space into a true retreat means giving sound the attention it deserves. Peaceful living starts with a quieter design, and we know how to help make that happen.

To create a tranquil and functional accessory dwelling unit in Boston, consider working with the expert team at Boston Construct. Our crew specializes in designing and building spaces that feel quiet, private, and beautifully finished. Learn how our builders of accessory dwelling units can help bring comfort and calm to your ADU project.