Do you want a deck, a wrap porch with a swing, or a bedroom loft? Will guests have full bathrooms, or will you prioritize construction costs for an open floor plan, large bedrooms, or a home office? Would you prefer large windows or a large kitchen? A dining area or a living room area? Are walk-in closets on your mind, or an open kitchen with marble islands and new appliances?
Building accessory dwelling units can be fun, but choosing your layout takes come careful calculations alongside your craftsman or general contractor.
We invited Cottage's Head of ADU Design and Delivery Anamika Goyal to share a few of the most common places where you can add to your ADU's value without breaking the bank. Anamika has designed all types of ADUs in all shapes and sizes as the head of Cottage's Design Studio. Previously, Anamika has held roles as an Architectural Designer at KieranTimberlake and a Design Manager at WeWork.
Alright, let's dive in!
Adding ADU Value and Quality Through Cost-Effective Design
CALEB: Thanks for joining our design discussion today, Anamika. Many homeowners have come to us with questions about their ADU design, and who better to hear from than Cottage's Head of ADU Design.
Can you start by walking us through some of the key areas where homeowners see advantages from a well-designed ADU?
ANAMIKA: Sure, happy to talk through this. We see a huge range of visions for ADU projects. I always advise homeowners to think through the long-term use cases for their project. This helps us both decide where to splurge and where to save.
Regardless of how you plan to use your ADU now, the reality of real estate is that keeping an eye towards resale is always advisable. The beauty of stick-built ADUs over prefab ADUs is that the unit will actually last for 50-100 years if not more - they're built to the same quality and with the same tried-and-true methods as your main home. It's challenging to balance customization and generalization for the highest equity and resale value for your property, but good design can effectively achieve both.
CALEB: That makes sense that your ADU design is the first place to start when thinking through the budget. What goes into good ADU design?
ANAMIKA: There are a few things we do in every Cottage ADU that ensure that your design meets your budget. First, we are great at sizing units. This means we've designed enough ADUs to confidently advise on ADU room shapes, sizes, and configurations that will work for your scenario, and be attractive for potential future users such as tenants or new owners if and when you sell your property down the road.
The downside of undersizing your ADU can be a loss of flexibility and comfort. On the flip side, the downside of oversizing an ADU is how quickly the additional square footage eats up budget without adding clear value to the interior space.
My advice here for homeowners is to have a clear sense of how much yard space you want to dedicate to the ADU, how many people you want living in the Cottage, and what level they would like to optimize for different uses of the cottage. From there, Cottage can help ensure that the sizing is appropriate and attractive. The best and most effective way to keep your project on budget is to control the square footage of the ADU.
Effective ADU Shape and Design for Roominess
CALEB: How about shape? Does that matter too for custom ADUs?
ANAMIKA: We often have folks get excited about uniquely shaped floor plans that might fit perfectly in a small nook of your yard or landscaping—which is completely understandable! However, our experience is that complicated designs can create interior spaces that are hard to use efficiently. And with ADUs, where every square inch counts, that is not always the right risk to take.
I've usually seen that strategic ADU placement and regularized ADU shapes (squares, rectangles, L-shapes) are the best of both worlds. They will match your property if placed correctly, let in the most natural light, and create the most optimal interior ADU spaces as well.
Speaking of daylight, we also talk to homeowners a lot about how to maximize solar gain and views in these ADU projects, which can sometimes be challenging given they are usually near other structures. However, the good news is there are plenty of effective ways to bring in sunlight without sacrificing privacy.
CALEB: Can you give a few examples of ways to add more light or roominess to the ADU space?
ANAMIKA: Sure! The first solution is that if you have a patio door or large window in your project, you can work with your designer to ensure its facing the best direction. Some folks love direct sunlight and should have south facing glass, others enjoy the strong afternoon sun and have west-facing glass, and still others appreciate having constant indirect sunlight—these should have north-facing glass wherever possible.
Usually, site constraints are going to play a big role in where openings can be, but it can be valuable to talk through this with a detail-oriented designer before you commit to the project.
A second valuable tip is to always have daylight from a minimum of 2 sides in every living room, such as a bedroom, kitchen, or living room. This allows you to have a variety of sunlight enter the space, as opposed to just one source that can create a backlit effect throughout the entire day. An exception to this might be a bedroom that you would only use for sleeping, in which case a single window can be a perfect design choice.
ADU Ceiling Height and Lofts
CALEB: One thing I considered for my personal ADU project was ceiling height; can you walk us through the tradeoffs here?
ANAMIKA: The Cottage team often meets homeowners that want to maximize a small footprint ADU with high ceilings, vaulted ceilings, skylights, and/or a loft.
Based on our current experience, we have found that high ceilings (either 9 ft or 10 ft) are less costly than vaulted ceilings. In addition, they make the space feel larger compared to standard 8 ft ceilings.
Furthermore, we sometimes suggest adding a large skylight in a flat ceiling instead of the vaulted option, which has several added benefits of adding sunlight, giving some height variation to the ADU space, and saving money compared to vaulted or even higher ceilings. Skylights certainly draw the eye up and expand the space considerably. For what its worth, I opted for high flat ceilings and skylights instead of vaulted ceilings in my own home and would do it again!
On the topic of lofts, I think the HGTV and tiny home trends have made lofts seem really appealing, when in reality they can be expensive, tough to access, and add less space than you think. I really wish they were as promising as they seem, but we have tended to guide homeowners away from ADU lofts for a few reasons:
Cost: The added structural components (e.g. framing of the ADU) and vaulted ceilings required to integrate a loft are going to add a five-figure expense.
Low Head Room: Staying within the ADU max height requirements (usually 16' for a 1-story ADU) means that the head space on the living areas below the loft can only be 7ft maximum, forcing the loft to be placed only above a bathroom or sleeping use only bedroom.
Minimal Usable Square Footage: The largest lofts can give you 120 sqft loft space, but then you have head height to consider. If the ADU is gabled with a vaulted ceiling, you will probably only be able to stand up in the very middle of the loft, where the peak is at the highest.
Difficult Access: The options are to use a ladder, which can have some safety concerns especially for older adults, or to build a proper staircase, which comes with another five-figures of cost and at around 20-30 sqft of space taken up from your main floor for the staircase.
For the reasons I just described, my recommendations are almost always to ditch the loft, design an attic with some accessible storage, and make the ground floor of the ADU as efficient and delightful as possible.
ADU Room Placement Options and Trade-offs
CALEB: For the last part of this conversation, can you talk a bit about how ADU room placement impacts cost once you've decided on the rough shape and size of the unit?
ANAMIKA: Of course! Our design team is great at thinking through some of the basics that'll ensure you can spend money on the stuff that matters.
Right off the bat, we configure our bathrooms, kitchens, and water heaters to be as close to each other as possible. This saves you money up front by minimizing the plumbing material needed for the ADU project, and it also saves you on your future energy bill too! The shorter your hot water has to travel from the tank to a bathtub, kitchen sink, or shower, the better.
You might notice in our floor plans that we work hard to keep your kitchen and bathroom adjacent and our 2-bathroom ADUs in a back-to-back configuration to save on plumbing and framing costs. Additionally, we like to think through ADUs from end-to-end: foundations inform walls, which inform doors and windows, which inform roofs. Thinking about any of those systems in isolation can raise the cost for your ADU unnecessarily.
One simple way the Cottage Design team thinks about this is by placing windows at appropriate distances from the corners of your ADU to minimize the steel hold-downs integrated into the foundation pour. All the while, we still create great proportions and natural light gain for the windows in your ADU space.
Another example is designing the ADU floor plan to have the longest continuous wall of the ADU to line up exactly with the roof ridge, which saves on the structural engineering later in the process. With these design and construction concepts in mind even before we step onto your property, we can ensure you are getting the best bang for your buck on your custom build ADU.
From Portland, Oregon to California's San Francisco Bay Area or Los Angeles, it's always a good idea to build an ADU for your single-family residence.
Once you've determined your city's ADU program, read up on the regulations, zoning ordinances, and fees, and gone through the permitting process to obtain your building permit, it's time for the fun part—actually designing your new housing units.
Whether you're attaching your ADU above your garage, converting a basement to an in-law unit, building a Junior Accessory Dwelling Unit (junior ADU or JADU), or adding a backyard cottage or granny flat to your single-family home to increase the floor area of your primary residence, to rent them out as rental units to gain passive rental income, or trying to create a supply of affordable housing in your neighborhood, there are so many choices to be made, and at times it can feel overwhelming.
Ready to talk about your ADU vision? Contact us today using the link below for a Free, No-obligation Consultation & Estimate for your ADU vision with one of our attached ADU and detached ADU experts and architects!