Very nice! if you make this frame a few feet deeper so the plant pot tops sit 1-3 feet below grade and tilt the glazing to the north (no sunlight) you can keep the temp more constantly cold and over winter plants that cannot take frost like in a root cellar with daylight but it will need some air circulation, if above freezing. I have a similar but deeper frame adjacent to my basement foundation with access to a basement window, with just a wood frame wrapped in plastic for a top, it is not air tight and the basement window allows some ventilation if i open it on sunny days. it is a great place to overwinter half hardy plants and grow miniature narcissus, cyclemen, etc. i get some sun in it for about 1 hr in a portion in the mid winter. the top is about flat on top, i like your pitch better, but the goal at construction was cold storage not a cold green house. you will be surprised what just a frame made of 2x12 plunged 6" into the grade with a sand base and flat top in full sun can do. again not air tight with some gaps , top made of plastic wrapped over a wood frame, the pots are full of crocus seedlings, some blooming, daphne cuttings, tough lilies, acis, and all sorts of stuff from the BX that would get distroyed in the open garden in the frigid midwest. Rimmer de Vries South of Ann Arbor, MI Zone 5 --- On Tue, 1/4/11, Kathleen Sayce <ksayce@willapabay.org> wrote: From: Kathleen Sayce <ksayce@willapabay.org> Subject: [pbs] cold frame pictures To: pbs@lists.ibiblio.org Date: Tuesday, January 4, 2011, 9:52 PM OK, I created a Flickr page and uploaded photos of this cold frame, and set the access to public. We used 2 inch thick styrofoam insulation, pressure treated wood outside, exterior marine plywood inside for the box. I will paint it, inside and out, in warmer, drier weather later this year, and primed only the top sections before they went into use this week. Tie downs for the sections to keep them on in heavy winds were installed yesterday. Still to come: another 6 inches of gravel inside, to ensure good drainage, and wedges to hold sections open during warmer weather, i.e. above 40 F, and a thermometer. At temps above 50 F, the tops will come off and be stored, unless I am using this frame to keep pots dry. Final dimensions are 4 ft x 12 ft x 2 ft deep. It's this deep because I plan to put 5 gallon buckets in it. I plan to get a roll of insulating cloth to lay over plants when temperatures below 25F are due, and will probably put a tarp over the top as well during heavy snowfalls. http://flickr.com/photos/n7ong-photos/… Now I can move all those pots out of my dining room too, and start eyeing those bulbs that like dry cool winters. And contemplate the next cold frame location, for smaller pots. Kathleen