We purchased the house with a “Greenhouse” but good Lord. Weak, shredded, photo-degraded plastic hanging from every square inch inside by staples; more spiderwebs and yellow-jacket nests than anything green, and the outside fiberglass panels were so old that no light could get in. So, gutted it all, slapped white paint on everything but the shelves, which I coated generously with dark walnut Danish oil, slapped on some new plastic panels, made a door from scrap lumber, and threw in a piece of the red carpet from one of the horror-movie-scene-looking upstairs bedrooms. Not sure how familiar you all are with red and blue light waves and their effects on plant growth, but the red helps the plants.