How to Begin Planning a Home Addition: A Guide for Homeowners

Adding onto your home is a big decision, and it’s often prompted by big life changes—like welcoming an aging parent or creating space for a growing family. After working with homeowners for years in both Dallas and Denver, we’ve learned that the process can be rewarding when you start on the right foot and understand the possibilities and limitations. This guide to planning a home addition will help you set off on the right foot

1. Define Your Goals

Before diving into your Pinterest boards and picking out tile, think about why you need more space. Is it for privacy, accessibility, or functionality?
One of our clients recently asked for help in adding a primary bedroom suite on the main level so their father could live with them comfortably. Knowing the purpose of the addition helped us design a space tailored to his needs—wide doorways, a curb-less shower, and a sitting area that overlooked the backyard garden he loves.

Having a clear picture of the end goal will keep us focused as we start planning the addition. Listing the rooms you need—including secondary spaces like hallways, stairs, closets, pantries, and mechanical rooms—will help you be realistic about the budget, time schedule, and resources required. Planning for these elements can also highlight areas in the current house that might need remodeling to make the addition flow seamlessly and function well for your family.

2. Evaluate the Feasibility of Your Addition

Not every house is a good candidate for an addition. Before we begin, we do our due diligence to investigate potential project restrictions and assess feasibility. This includes reviewing zoning regulations, identifying structural constraints, and examining utility capacity to ensure your property can accommodate the changes.

Here are key factors we consider:

zoning and setback requirements

We check your local zoning laws to see if your property allows for an addition. Most neighborhoods have strict setback rules that limit how close you can build to the property line. There are also restrictions on how tall a home can be and how much of the lot your home can cover.

historic districts and design guidelines

In older neighborhoods, homes were often built before zoning regulations were put in place. This can create a unique challenge where part of the home is considered “non-compliant” because it already violates a setback line. In a remodel and addition project in a historic Dallas neighborhood, we worked around this by carefully planning the addition to remain within the allowed area of the lot while maintaining the home’s flow and functionality.

This property in a historic district presented some challenges. The home was built in 1937, before zoning regulations were introduced. Through no fault of the current owner, the home overlapped the setback lines (shown in red)  in several places. We could not change any part of the house that was outside the setback lines. Creative planning of the addition meant we placed the new square footage to the rear of the house inside the allowable building envelope.

Historic designated areas can also come with detailed design guidelines and architectural review requirements. The goal of the guidelines is to maintain the original personality of the streets by regulating the styles, materials, colors, size, and architectural features allowed. We study these requirements to ensure the addition to your home is compatible and compliments the original structure. It is our goal to integrate the addition to your home so it looks like it has always been there.

An example of design guidelines in a Dallas historic district.

This addition, which added 1,822 square feet to this 1937 home, was placed in the back of the house. The character of the front of the house was maintained during the renovation by following the historic district design guidelines.

hoa submittals and approval

If your home is within a Homeowners Association (HOA) or Property Owners Association (POA), you might be required to follow certain rules as you plan your home addition.
Submitting your plans for review by an architectural review committee is a necessary step in the process, and approvals can take time. Be prepared to provide floor plans, exterior elevations, material samples, and sometimes even renderings to demonstrate how your addition will fit within the community guidelines. Some HOAs may require specific landscaping or color schemes to ensure the addition matches the neighborhood aesthetic.
We suggest starting this process early, building positive relationships with committee members, and respecting their submittal schedule to help avoid delays.

structural constraints

Your home’s foundation needs to support the addition. For example, a one-story home on a basic concrete slab might require significant reinforcement if you plan to add a second story.
A structural engineer can assess the existing foundation. Additionally, engaging a geotechnical engineer to do a soil sample and generate a detailed soils report is important for a well-designed foundation and is required by some communities. The engineer’s recommendations will tell us if we need to plan for additional concrete piers or isolate the grade beams to deal with extreme soil movement.
On a recent project, it was determined that the existing foundation would not support the second floor envisioned by the client, so we pivoted and designed an addition to the back of their home.

Some homes, like this one built in Dallas in 1929, have brick foundations. Depending on the soil conditions, the existing foundation may not be able to support the weight of an addition.

The addition to this older home was placed to the rear of the structure where a new concrete foundation could be added without affecting the existing brick foundation.

Your home’s foundation is not the only structural consideration. Adding a second floor over your existing kitchen, for example, would involve removing the ceiling and disturbing the lighting and cabinets. Most likely, larger joists would be required to support the new rooms above. In other words, it would be a big mess and you would lose the use of the kitchen during the construction of the addition.

In a project in the north Dallas suburb of Richardson, we encountered this exact challenge. In order to not disturb the first floor rooms, we opted to leave the ceiling drywall and structure in place. We added a new floor above with its own floor framing, space for HVAC ducts, electrical, and plumbing with minimal disturbance to the first floor spaces.

New floor joists are added above the existing ceiling framing to minimize the disturbance of the homeowner’s first floor rooms.

lot size and topography

Small lots, steep slopes, or properties with poor drainage can complicate the design process. These challenges might require creative solutions, such as cantilevered designs or engineered drainage systems, which can increase construction costs but make the project feasible.

In rare situations, you may have to apply for a zoning variance with the city’s building department. Working with an experienced architect can help you navigate these complexities and find the best solutions.

tree conservation

Counting and measuring trees on your property might sound like an obscure requirement, but some communities have restrictions on cutting down trees. Tree conservation has a direct impact on the appearance of the neighborhood and can enhance resale values.

This driveway was designed to work with existing trees on the site. Fencing the area around a tree is important during construction. Repeated use of heavy equipment too close to a tree can cause damage to the root system.

A tree survey shows the location and size of trees on your property. The larger circles represent the drip line—the outer edge of the tree’s canopy.

 We have worked on a number of projects that necessitated calling the surveyor to do a tree survey. This process calculates the circumference around the trunks of the trees. The homeowner may be required to replace the same number of inches in new trees as in the trees that are removed during construction. For example, if an existing tree that is to be removed measures 15 inches around the trunk, it can be replaced with 3 smaller trees measuring 5 inches each.

While we always try to preserve trees on a property, sometimes it is necessary to remove a few to get the space we need in a home. In that situation, we advise the homeowner and plan for new trees to be planted when construction is complete.

utilities and infrastructure

Extending plumbing, electrical, and HVAC systems can reveal hidden issues. For instance, during one addition project, we uncovered outdated wiring that couldn’t handle the additional load and had to add a second electrical panel.

On another project, we discovered that the existing cast iron sewer line under the house was rusted though in many places and had to be completely replaced. If your renovation involves adding more plumbing fixtures such as toilets, sinks, and showers, consider the impact on existing sewer lines and the capacity of your current water heater. Upgrading these systems will ensure the new space functions as expected.

3. Plan Your Budget Wisely: Balancing Dreams and Reality

Adding onto your home is a significant investment, so it’s important to balance your dreams with your financial reality. Start by evaluating what your family can afford. One client we worked with initially planned an elaborate two-story addition but scaled back to a well-designed single-story project after reassessing their budget. Consider how the cost of the addition fits into your overall finances, including any loans or financing options you might need. It’s also wise to set aside a contingency fund for unexpected expenses that often arise during construction

Equally important is understanding how much you can afford to invest in your home without overbuilding for your neighborhood. Adding high-end features to a modest home in a less expensive area might not yield a return on investment when it’s time to sell. Research local property values and consult with a real estate agent or appraiser to ensure your addition aligns with neighborhood trends.

Finally, think about long-term value. While you might not recoup every dollar spent, additions like main-level bedrooms, energy-efficient upgrades, or expanded kitchens often add substantial resale value. A well-planned addition should enhance both your family’s lifestyle and your home’s marketability.

4. Work with Experienced Professionals

Even experienced homeowners can feel overwhelmed by the technical aspects of planning a home addition. Start your conversation early in the process with an architect who specializes in residential projects. We can help you evaluate your property, navigate zoning regulations, and create a design that works for your needs and budget.

Over the years, we have worked on a variety of addition types, from garage apartments and second-story additions to guest wings and expanded primary bathrooms with luxury closets. Specialty spaces, like fully finished-out detached garages for auto enthusiasts or accessory dwelling units (ADUs), are becoming increasingly popular. These additions not only add functional space but can also be customized to enhance your lifestyle.

We also recommend bringing in a contractor early in the process. They can provide insight into construction costs and timelines, which helps you set realistic expectations from the start.

5. Think Long-Term

An addition isn’t just about extra square footage. It’s about making your home work better for your life. One of our favorite success stories was a family who added a second-story game room for their teenage kids. It became the go-to hangout spot, giving the parents peace and quiet downstairs and strengthening family bonds over movie nights and board games.

But it’s not just about today. Think about how the addition will impact your home’s resale value and energy efficiency. A poorly designed addition can feel like an afterthought and may even lower your home’s value. A thoughtful design, on the other hand, will enhance both your daily life and your property’s appeal.

Ready to Take the First Step?

If you’re considering a home addition, we’d love to help. With years of experience designing thoughtful spaces, we’ll guide you through every step—from evaluating your property’s potential to creating a space that works for your family’s unique needs.

Reach out to schedule a consultation. Our architects will guide you from the initial concept to the final walkthrough, ensuring a seamless process tailored to your unique needs. Let’s explore how we can make your home work even better for you.