Spring has sprung, and as temperatures rise across the country, so does interest among homeowners for sprucing up around the house and remodeling.

Spending on home improvements is expected to grow nearly 5 percent in 2018, according tothe National Association of Home Builders (NAHB), as below-normal rates of home building are creating an aging housing stock.

But many homeowners during a remodel focus on what can be seen and not necessarily on important things that can’t be seen. The systems and functions of a home remodel are as important as the aesthetics, says Jennifer Franz, a home comfort expert at Lennox.

She offers the following tips to help ensure a remodel factors in other areas such as energy efficiency, comfort and practical function:

Up:Ventilation is an important component when expanding a home and adding extra roofing footage. Attic ventilation has an impact on the functionality and lifespan of a roof. Although the requirements vary per region, the National Roofing Contractors Association recommends a minimum of one square foot of free vent area space in between the roof and home for each 150 square feet of attic floor.Vented roofs can remove moisture and reduce temperature, both of which protect the home and roof from weather damage.

Down:When adding flooring in new spaces, homeowners should consider installingradiant floor heating. This technology is especially useful in spaces like entryways, bathrooms and sunrooms. During the winter, the electric floors can be heated, which will help maintain comfort in a room that otherwise may drop significantly in temperature. Electric floor installations might seem daunting but are as easy to install as regular flooring and can add resale value to a home, especially in areas of the country that experience longer and/or harsher winters.

Outside:Updating the exterior of the home may change its appearance, but it also can significantly improve the home’s energy efficiency. Outdated siding can allow hot and cold air to escape from the home, which subsequently raises the homeowner’s energy bill. If replacing siding, consider adding two staggered layers of rigid exterior insulation to the outside of the sheathing. This will greatly improve the insulating value of the home’s walls.

Inside:According to the National Association of the Remodeling Industry (NARI), whenever space is added to a home, it’s important to have an HVAC contractor determine whether the existing HVAC system can accommodate the extra square footage. For a room addition that doesn’t have existing ductwork, homeowners could consider a ductless system, which is more cost-efficient for rooms that aren’t used continuously or when ductwork isn’t feasible.