How to Insulate a Sun Porch

Replace all screen windows with glass panels. Check for drafts coming through the window frame and the glass panels and seal them as needed. Use polyurethane caulk or insulation foam or fabric to seal any gaps. Place heavy curtains over the windows to further warm the room and block drafts.

Insulate your porch from below if applicable by crawling under the porch and nailing foam insulation sheets to the porch underside to seal gaps between wooden floor boards.

Apply a glaze to all windows to insulate your sun porch. Use a high-quality glaze designed to retain heat when needed; such glazes also work to block sunlight when necessary. Glazes also prevent sun damage to furniture and rugs.

Place a thick rug on the floor of your porch as additional protection against drafts from below. Use multiple rugs if necessary so the entire porch floor is covered.

Apply weatherstripping materials to porch doors for insulation and draft-blocking purposes. Weatherstripping kits come with wood or metal-covered foam flanges designed to insulate your entire door frame save the bottom. You will have to measure your door frame before purchasing a kit; use a hacksaw to cut flanges to size.

Install a door sweep at the bottom of your door to keep drafts out. If rugs are higher than the bottom of the door frame, use rolled-up towels to block drafts. Measure the width of your door frame before purchase and use a hacksaw to make adjustments to the sweep as needed.