Building a Sunroom on a Solid Foundation


Homeowners often ask if they can build a sunroom on their deck or a concrete slab or patio.

Sunroom Basics To Consider When Building

Have your contractor pull the sunroom building permit. This is important because if a homeowner pulls the permit, he or she assumes all liability for onsite injuries, damages, etc. The contractor you choose to build your sunroom should be licensed and insured. Ask for proof. In addition to a building permit, your contractor may also pull a Zoning Permit, Electric Permit and possibly a Heating-Cooling Permit to build a sunroom. Clearview Sunroom and Windows takes responsibility for all needed permits its customers require.

Building a Sunroom Floor - Be Sure Your Floor Will Last

Typical wood floor construction requires 18” diameter sonotubes, which are concrete filled to the ground level, 48 inches below grade. This gets the concrete below frost level and keeps your 6 inch x 6 inch posts from touching the ground to avoid rotting. One set of footings is needed at the front of the sunroom for room dimensions up to twelve feet away from the home. Projections past 12 feet usually require additional center support footings.

The wood sunroom floors Clearview builds are all 2 inch x 10 inch green treated Kiln Dried After Treatment – KDAT – joists 16 inch on center with double or triple outside rim joists under the walls of the sunroom.

KDAT lumber is used to eliminate twisting and cupping of the boards, plus it is dried to 19% moisture to shrink the board to its correct size. This eliminates floor shifting caused by use of regular green treated lumber, purchased from mass merchandisers. The floor Clearview designs includes many specially prepared beams and components, strategically placed hardware, insulation and adhesives to ensure durability and function. An example of how a floor needs to be built to pass code is in the Clearview showroom. It is an excellent resource for a homeowner.

concrete footing
Building Codes require concrete footings be below frost level, 48” below grade. The metal shoe stabilizes your sunroom and protects your posts from rotting.

Concrete — An Option For Your Sunroom Floor?

Concrete is an option, however costs are higher when building on a concrete base for your sunroom. Excavation causes more yard damage than building a wood floor. There are specific code requirements relative to how the foundation is designed, including steel rebar, mesh and insulation.

When given a choice, concrete floors are not as popular as wood floors. Ask your contractor for details. Building a solid foundation will ensure your new sunroom will serve your family for a long time.

Four Season Sunroom Heating and Cooling

When your sunroom and its foundation are insulated according to UDC code, heating – cooling options become available. When a sunroom is attached to a home and has a

thermally insulated door between the home and sunroom, the sunroom can be heated as a four – Season sunroom. 

This door can be a conventional swing door, French door or a sliding door. Taking the door out and opening the room to the home converts the sunroom to an addition of square footage instead of a sunroom. This is significant because taxes will usually be lower when building a sunroom compared to an addition of square footage. Of course, each municipality has its own unique tax code, so it’s important to get the details for your area.

Remember, with a four season sunroom, a permit must be pulled if it has a permanent heating source, as opposed to a removable space heater. Permanent heating sources such as fireplaces, biomass stoves, baseboard heat, furnace runs and heating-cooling heat pump units can all be used for a sunroom or addition.


Get in Touch
Looking to Add a Sunroom to Your Home?

We’re here to help! To get started on your next project, or to schedule a free consultation, contact ClearView Sunrooms & Windows today at (608) 226–9800.