7 Considerations When Adding a Second Story

Adding space to your home at the second or even third story can capture views, maximize square footage on a small lot and let you locate all the bedrooms on a single level. However, there are many things that need to be considered before beginning your project.

Whole-house impact. The design and function of a second-story addition will have a ripple effect on the rest of your home — everything from finishes to mechanical work to structural work. A good design will make the second story look like it was always intended, so take the necessary time to make sure the addition adds to your curb appeal and your home’s functionality.

Structural requirements. A second story with occupied rooms will weigh much more than your old roof system, so engineers will need to calculate how much weight the main-floor walls and foundation will carry and how to hold that weight up. Second stories require structural support that includes adding plywood and steel connections at main-level walls and down into the foundation to meet code requirements.

Stairs. A new staircase needs to be incorporated into the design. Sometimes it makes sense to do over existing ones going to the basement. But sometimes a little creative thinking is required. Your designer can help thoroughly examine all of the options for stair location that will yield the best results.

Mechanical. Your furnace, water heater and electrical panel all work based on your home’s square footage and the number of fixtures you have. When you increase the size of your home, you have to revisit all of these systems.

Electrical panels are typically upgraded to 200 amps, and HVAC systems can be replaced, added on to or have new zones added, depending on whether they are forced-air or radiant systems. Hot water can be delivered in a number of ways — from tankless heaters with recirculating pumps to tank systems and separate on-demand systems just for a master bathroom. You could consider adding an energy-efficient system too, such as ductless heat pumps, geothermal heat pumps and solar-assisted hot water or photovoltaic panels.

Windows, doors and siding. When it comes to windows, doors and siding the big question is– Should you match them? Start over? Do half and half? If structural work at the main level requires removing half of the siding, you may wonder whether or not the whole house should have new siding. If main-floor windows and doors are tired, rotting, don’t meet energy code or are simply out of style, should they all be replaced?  Regardless of the decision, making it early in the process is key.

Insulation. When engineering requires old siding and sheathing to be removed from your home’s exterior, it also presents the chance to install new insulation. Homes built in the 1950s or earlier tend to not have insulation in their walls (aside from the occasional newspaper). Installing fiberglass batts or even rigid insulation in the studs is a great way to improve the energy efficiency of your whole home.

Finishes. Often the finishes of your existing home — door style, trim sizing, Sheetrock finish, and flooring — can dictate the finishes in your addition. But adding a new story allows you to revisit every finish. If you have textured walls, for instance, you may decide to go with smooth walls in the whole house or just in the addition.