Adding on to your home is a major time commitment. But it’s also exciting to watch as the structure takes shape and comes together. If you’re considering a home addition, understanding how long the build will take is an important part of the planning process.
We’ve designed and built home additions throughout the Portland area, and no two have followed exactly the same schedule. Structural work, permits, product lead times, weather, and custom details can all add time to the build. In this article, we use a sample 14-week project to show what happens during foundation work, rough-in, and finish work.This article will discuss the timeline for the construction of a home addition, broken down into 3 phases. By the time you finish reading, you should have a better understanding of the time it takes to build an addition. Here are the different phases we will discuss:
If you’re working with a qualified contractor to build an addition to your home, they will provide you with a set of design plans from an in-house designer or independent architect. These plans should outline the entire scope of work, including what changes will be made, what methods will be used, and which products and materials will be required.
Having a set of design plans will help your project manager predict the timeline for your home addition more accurately. There are several factors that can affect the timeline of an addition. By using the plans as a guide, your project manager can create a schedule that will give you a better idea of how long the project will take to complete.
This article uses a standard 14-week schedule for a single-story, ground-level addition as an example. Depending on the size, scope, and complexity of your addition, it may take shorter or longer.
During the first phase, your team will begin by laying down the concrete foundation of the addition. As the base layer of the entire structure, it’s important to put in the necessary time and effort to prepare, construct, and inspect the foundation before moving on to the rest of the project.
You’ll meet on-site with your entire team to discuss the project ahead. If you work with a design-build firm like Lamont Bros., the build team may give you a presentation that covers their construction schedule, site protection plan, and any safety concerns that you need to be aware of.
They should also explain how your addition project could impact your daily routine during the construction phase. This is your chance to ask any questions you may have and to communicate any house rules to the contractors.
Following the preconstruction meeting, your team will get to work excavating the construction site. During this process, they will use heavy machinery to clear a level space for the foundation.
Concrete forms are temporary structures used to contain and shape concrete as it sets and hardens. They are traditionally made of wood and function as a mold for the foundation. Forms are assembled on the construction site prior to pouring the concrete. This process generally takes an entire week.
Once built, an inspector will ensure that the forms are built to code and ensure that the steel rebar is placed correctly. It is important to note that this inspection comes before the concrete itself is poured. This is because it is much easier to adjust the forms and rebar than it is to demolish and re-pour concrete later on.
By the start of the third week, the first permanent structure for your addition is on its way. Your build team will fill the foundation forms with concrete and allow them to dry. Typically, the concrete needs about 7 days to dry before framing can begin. During this week, you won’t see much construction activity except the occasional check-in.
During the rough-in phase of a home addition, the major structural and utility components are installed. This stage can be exciting for homeowners as they get to see their vision for the new space starting to take shape. Since these components make up a major part of the project’s design, it is common to see a lot of progress in a relatively short amount of time during this phase.
It usually takes a minimum of two weeks to complete the framing of an addition. During this process, your construction team will use lumber to craft the floors, walls, and roof trusses that form the structure of the addition.
The framer in charge of the job must pay close attention to detail and adhere to strict construction code requirements. Additionally, they must also consider the placement of every door, window, and exterior vent in the framing structure.
After the framing process is finished, the next step is to install both the roofing and sheathing. This can often be done at the same time.
The team responsible for the roofing will install the shingles to protect the newly constructed structure from weather elements. Simultaneously, the other team will install the sheathing, which serves as both a weather barrier and provides additional structural support to the frame walls.
Once the interior of the addition is enclosed, it is time for the rough-in installation of the electrical, plumbing, and HVAC systems. This stage of the construction process requires the involvement of several subcontractors. Therefore, you’ll probably see a few new faces during this time.
During the rough-in installation, the subcontractors will primarily work on the major systems that run inside the walls. The plumbers will install the water supply and drainage lines. The electricians will be responsible for installing the electrical boxes, wiring, and any appliance hookups. Similarly, the HVAC installers will be adding the ducts, vents, and piping required to distribute hot and cold air throughout the building.
Before moving on to the third and final phase of the build, the completed rough-in structure requires an inspection. The purpose of the inspection is to ensure that the structure and rough-in utilities are properly installed and meet building code requirements.
If the inspector identifies any issues or code violations during the rough-in inspection, the construction team will need to make any necessary corrections before proceeding with the project.
During the final 6 weeks of your addition build, it may feel like the project has slowed down. Don’t be discouraged — finish carpentry is a construction art form that requires extreme care and fine attention to detail. You’ll get to watch the space go from a shell to a home as your build team works tirelessly to put the finishing touches on your addition.
The exterior of the addition is often the final step in the process. The exterior siding in an important part of the building envelope, and when installed correctly, can protect your home for over 50 years.
Once the exterior trim and paint are complete, your build team will address any lingering issues, fix the items on your final punch list, and close out the job.
With the utilities installed and approved, it’s time to close up the walls. Insulation goes in first to ensure that your addition can maintain a good internal temperature and stay energy efficient.
Then comes the drywall, which will take up most of the week due to its lengthy installation process. The higher-quality drywall finish you’ve requested, the longer the installation will take to complete.
The following two weeks will consist of finish carpentry work. This will include everything from door and window casings to installing new plumbing fixtures. At the end of the two weeks, the trim, flooring, and paint should be fully installed.
At the end of the 11th week, you’ll do your 95% walk-through. The purpose of this meeting is to tour the addition in a state of substantial completion. You’ll get to see the project in its ending phase and provide a final punch list to your build team of things to fix before closeout.
Before your addition is officially ready to live in, it will need one final inspection. The purpose of this inspection is to ensure build quality and code requirements. It’s also an opportunity to check for things that might have been overlooked in previous inspections.
Lastly, a professional photographer may come and photograph your completed addition to memorialize the project. You’ll get to keep a set of the final photos to show your friends and family.
A home addition should do more than add square footage. It should solve a problem that your current home can no longer handle, such as a crowded kitchen, a missing bedroom, a lack of privacy, or the need for a dedicated place to work.
Visit our Additions Portfolio to see completed Lamont Bros. projects. As you look through the examples, pay attention to how each addition connects to the original home, how the new layout changes the surrounding rooms, and how the exterior design makes the new construction feel intentional.
If you have an addition in mind, schedule a free video call with one of our designers. Tell us what is no longer working in your home, what you want the new space to accomplish, and how long you plan to stay. Bring your questions about cost, timing, design, permits, or construction. We can discuss the project and identify the issues that deserve attention before you commit to a plan.