Want to buy ADU & small house plans that fit your backyard, your budget and your city's rules? You are in the right place. At HousePlans USA, we draw accessory dwelling units, granny flats, garage apartments and small homes from scratch. Every plan is designed for your lot, your local code and the way you plan to use it.
Small homes are having a big moment in America. Housing costs keep rising, and families want flexible space. Meanwhile, states like California, Washington and Oregon have passed laws that make ADUs easier to build. As a result, homeowners are adding backyard cottages for parents, adult children, renters and home offices.
However, small homes are surprisingly tricky to design. Every square foot must work hard. Moreover, setbacks, parking, utility connections and height limits vary by city. Therefore, a generic tiny home plan rarely fits your lot without changes. We draw every small home from scratch instead, and customization is always free. Plans start at just $1,050. Start your ADU design online in about ten minutes.
What Is an ADU?
An accessory dwelling unit, or ADU, is a second, smaller home on the same lot as a main house. It has its own kitchen, bathroom and entrance. ADUs go by many names, including granny flats, in-law suites, backyard cottages and casitas.
Types of ADUs
There are three main types. A detached ADU is a separate small building in the backyard. Meanwhile, an attached ADU shares a wall with the main house. Finally, a garage apartment sits above or inside a garage. Some states also allow junior ADUs, which are small units carved out of the main home. See our cottage house plans for small-home inspiration.
Why Build an ADU?
ADUs serve many purposes. For example, they house aging parents close by but with privacy. Similarly, they give adult children an affordable first home. Moreover, they can earn steady rental income that helps pay the mortgage. In fact, many owners say their ADU paid for itself within a decade.
Our Services: ADU and Small House Plans by State
We draw ADU and small house plans for every state. Below are the markets where demand is strongest. Each plan includes floor plans, elevations, sections, roof plans and foundation details. Furthermore, you get 30 days of free revisions after delivery.
Buy Small House Plans and ADU Plans in California: Los Angeles, San Diego and San Jose
California leads the nation in ADU construction. State laws now require cities to approve most ADUs that meet basic standards. Consequently, homeowners across the state are adding backyard units.
We draw plans for every California market. For instance, buyers who purchase ADU plans in Los Angeles, CA often want a one-bedroom unit with a private patio. Meanwhile, San Diego CA garage apartment blueprints convert or rebuild garages with living space above. Similarly, San Jose California tiny home blueprints maximize every inch on small Silicon Valley lots. See our building guides for Los Angeles, San Diego and Sacramento.
California also has strict energy and seismic rules. Therefore, our plans show shear walls, hold-downs and solar-ready roofs clearly. Learn more on our California house plans page.
Buy Affordable House Plans in Florida: Orlando, Tampa and Jacksonville
Florida buyers want small homes that stand up to hurricanes. Therefore, we often draw concrete block cottages and ranches with impact-rated windows. Moreover, compact homes cost less to insure and cool.
For example, Orlando FL 2 bedroom house blueprints suit retirees and first-time buyers. Meanwhile, Tampa Florida narrow lot house plans fit tight infill lots in Seminole Heights. Similarly, Jacksonville FL small ranch house blueprints offer easy one-level living. Read our local guides for Orlando, Tampa Bay and Jacksonville.
Florida guest cottages also make great pool houses. For example, a small cottage with a bath and kitchenette can serve swimmers by day and guests by night. Learn more on our Florida house plans page.
Buy Granny Flat Plans in Washington State: Seattle, Spokane and Tacoma
Washington State now requires most cities to allow ADUs on residential lots. As a result, backyard cottages are booming from Seattle to Spokane. Granny flat plans in Washington State are among our fastest-growing requests.
Seattle WA backyard ADU blueprints often include a sleeping loft and big windows for gray winter days. Meanwhile, Spokane Washington small home floor plans must handle real snow and cold. Similarly, Tacoma WA detached ADU blueprints for sale suit the city's many older neighborhoods. See our building guides for Seattle, Spokane and Tacoma.
Washington also has strict energy codes. Therefore, we design well-insulated, airtight small homes. Learn more on our Washington house plans page.
Buy Affordable Home Plans in Oregon: Portland, Eugene and Salem
Oregon was one of the first states to open neighborhoods to more housing types. Consequently, ADUs and small homes are common in Portland, Eugene and Salem.
Portland Oregon ADU blueprints for sale are popular in Southeast and Northeast neighborhoods. For instance, a one-bedroom unit with a covered porch suits Portland's rainy climate. Meanwhile, Eugene OR small house floor plans appeal to students, faculty and retirees. Similarly, Salem Oregon narrow lot home blueprints fit tight urban lots. See our building guides for Portland and Eugene, or visit our Oregon house plans page.
Buy Small Cottage Plans in New York: Albany, Buffalo and Rochester
Upstate New York offers affordable land and a strong demand for starter homes. Therefore, small cottage plans in New York are a smart choice for first-time buyers and downsizers.
For example, Albany NY 3 bed ranch blueprints offer one-level living with a full basement. Meanwhile, Buffalo New York affordable house plans must handle heavy lake-effect snow. Similarly, Rochester NY small cottage floor plans suit narrow city lots and quiet suburbs. See our building guides for Albany and Buffalo, or visit our New York house plans page.
New York's cold winters call for tight, well-insulated homes. Therefore, we often suggest 2x6 walls, full basements and simple roofs that shed snow. As a result, small upstate homes stay warm and affordable to heat.
Buy Guest House Plans in Texas: Austin, Houston and Dallas
Texas homeowners love backyard guest houses. They host visiting family, short-term guests and home offices. Moreover, many Texas cities have eased rules for second units.
Austin TX backyard ADU blueprints are especially popular after the city's housing reforms. Meanwhile, Houston Texas small garage apartment plans suit the Heights and Montrose. Similarly, Dallas TX affordable ranch home blueprints offer simple, low-cost living. Read our local guides for Austin, Houston and Dallas–Fort Worth.
Texas heat shapes every small home. Therefore, we use deep porches, shaded windows and good insulation to keep cooling bills low. Learn more on our Texas house plans page.
Tiny Homes, Starter Homes and Small Ranch Plans Nationwide
Not every small home is an ADU. Many buyers want a compact main home on its own lot. For example, a 1,000-square-foot two-bedroom ranch is perfect for retirees and first-time buyers. Similarly, a small cabin makes a great weekend retreat. See our ranch house plans and cabin and A-frame plans.
Small homes save money in many ways. They cost less to build, heat, cool and insure. Moreover, they are easier to clean and maintain. As a result, a well-designed small home can be the smartest financial choice you make.
Smart Design Ideas for Small Homes and ADUs
Great small homes feel bigger than they are. However, that takes careful design. Here are the techniques our designers use most.
Open Living Spaces
Combining the kitchen, dining and living areas makes a small home feel spacious. Therefore, most of our ADUs use one open great room. Moreover, vaulted ceilings add volume without adding floor area. Even one tall wall of windows can make a 400-square-foot room feel generous.
Built-In Storage
Every inch counts in a small home. Consequently, we plan built-in shelves, window seats with drawers and storage under stairs. Similarly, a pocket door saves the floor space a swinging door would need. A fold-down desk or Murphy bed can also turn one room into two different spaces.
Light and Views
Big windows and glass doors make small rooms feel open. As a result, we place windows to capture light and views while protecting privacy from the main house. Moreover, a covered porch extends living space outdoors.
Lofts
A sleeping loft adds a bedroom without adding footprint. For example, a 500-square-foot cottage with a loft can sleep four people comfortably. However, lofts need safe stairs or ship's ladders and enough headroom, so we plan them carefully.
Aging in Place in an ADU
Many ADUs house aging parents. Therefore, accessible design is essential. For instance, a zero-step entry, wide doors and a curbless shower make the home safe for decades. Similarly, grab-bar blocking in bathroom walls allows bars to be added later. Moreover, a single-level layout avoids stairs entirely. Lever door handles, rocker light switches and a front-loading washer also make daily life easier for older residents. As a result, your parent can stay independent while living close to family.
Renting Out Your ADU
Rental income is one of the biggest reasons to build an ADU. However, a rental unit needs a slightly different design than a family suite. Therefore, plan with your tenant in mind from the start.
Privacy comes first. For example, a separate entrance, its own path from the street and windows that don't face the main house make both homes feel independent. Similarly, separate utility meters make billing simple. Moreover, a small private patio or porch adds real appeal for tenants.
Durability matters too. Consequently, we suggest hard-wearing floors, simple fixtures and a compact laundry closet. Before you rent, check local rules on long-term and short-term rentals, since they differ widely. As a result, your ADU will be ready to earn income from day one.
Budget Tips for Building an ADU
ADUs can cost more per square foot than large homes. That is because kitchens, bathrooms and utility connections are expensive no matter how small the unit is. However, smart design keeps costs in check.
First, keep the shape simple. A rectangle with one roof line is the cheapest to build. Second, place the kitchen and bathroom back-to-back, so they share plumbing walls. Additionally, locate the ADU close to existing sewer and water lines to shorten trenches.
Converting an existing garage can save money too. However, older garages may need new foundations or insulation to meet code. Therefore, ask a builder to inspect the structure first. We also offer a cost-to-build report for your ZIP code, so you can check your budget early.
Interior Design Ideas for Small Homes
Small homes look best with a light, simple palette. For instance, white walls, light wood floors and one bold accent color keep rooms feeling open. Similarly, wall-mounted lights and floating vanities free up floor space. Our interiors gallery lets you save looks you love during design.
ADU Rules and Permits
ADU rules vary widely by state and city. For example, California and Washington have state laws that limit what cities can require. Meanwhile, other states leave ADU rules entirely to local governments. Common rules cover size limits, setbacks, height, parking and owner occupancy.
Therefore, check your city's ADU rules before you design. Send us your lot details and any local requirements. Our designers will plan a unit that fits. Visit our house plans by state hub to learn your state's general requirements.
Choosing Where to Put Your ADU
Your lot decides what is possible. Therefore, start with a survey showing property lines, the main house and any easements. Also note where water, sewer and power lines run, since connecting utilities is a big part of the cost.
Rear yards are the most common ADU location. However, corner lots and alley lots offer extra options. For instance, an alley lot may allow a garage apartment with its own entry. Meanwhile, protect existing trees and sunny garden spots where you can. Also think about how tenants or family will reach the unit, especially at night. Send us your lot details, and we will plan around them.
What Do ADU Plans Cost?
Custom plans start at $1,050 for homes up to 1,000 square feet. Moreover, customization and 30 days of revisions are included. Most ADUs fall into this first price tier, which makes them one of the most affordable projects we design. Add-ons like engineer stamps, energy reports and CAD files are listed on our pricing page.
Why Small Home Buyers Choose HousePlans USA
Several Designers, One Winning Concept
Two or more designers sketch a concept for your small home. You compare them and choose your favorite. As a result, you see fresh ideas before you commit.
Free Customization and Fast Delivery
Your instructions are included in the price. Moreover, revisions are free for 30 days after delivery. Standard delivery takes ten business days. However, Rush and Super Rush deliver in 48 or 24 hours.
How Ordering Works
First, choose your style, rooms and foundation in our online designer. Next, compare concept plans from several designers. Then, approve your final plans and download them. Your builder can begin pricing and permitting right away. Questions? Contact our team, or browse our interior design ideas and all home styles.
Frequently Asked Questions
How much do ADU plans cost?+
Custom ADU and small house plans start at $1,050 for homes up to 1,000 square feet. Customization and 30 days of revisions are included.
Can you design a garage apartment?+
Yes. We design apartments above or inside detached garages, as well as new garage-and-apartment buildings.
Will my ADU plans meet my city's rules?+
Send us your local ADU rules and lot details. We design the unit to fit setbacks, size limits and height limits.
Can you design an ADU for an aging parent?+
Yes. We design accessible ADUs with zero-step entries, wide doors and curbless showers.
How fast can I get ADU plans?+
Standard delivery takes ten business days. Additionally, Rush takes 48 hours, and Super Rush takes 24 hours.
Start Your ADU or Small House Plans Today
From Los Angeles backyards to Buffalo starter homes, we design small homes for every state. Our designers make every square foot count. Call or WhatsApp us at +1 (217) 426-5403, or get your free quote today.
Our service area around CA, FL, WA, OR, NY & TX
We draw plans for lots across CA, FL, WA, OR, NY & TX and every nearby town, plus all 50 states. Call +1 (217) 426-5403 or email hello@house-plan.net.
