If you're trying to furnish a balcony, rooftop, or small city patio without spending a lot, I'd put recycled HDPE at the top of the list. HDPE—high-density polyethylene—is the same kind of plastic used in milk jugs and shampoo bottles, and recycled HDPE outdoor furniture is often made with post-consumer recycled content. That matters in a city, where furniture gets hit by rain, sun, pollution, and temperature swings.
The reason I'd choose it over most “eco” options is practical: it does not need sealing, painting, or fussy winter storage. A lot of budget outdoor furniture looks good for one season and then cracks, fades, or loosens. Good recycled HDPE pieces are dense, UV-stabilized, and built with stainless or coated hardware, so they hold up. They're also easy to wipe down and often repairable. If a board or slat gets damaged, you can usually replace it instead of tossing the whole bench.
When people ask me about eco-friendly outdoor furniture, I tell them to compare the whole lifespan, not just the sticker price. FSC-certified wood is lovely, but even budget versions need oiling or sealing and may not last as long in wet urban conditions. Powder-coated recycled aluminum is another solid option—light, rust-resistant, and recyclable—but it can cost more and may dent. Bamboo can be sustainable, but cheap outdoor bamboo often struggles with moisture. Reclaimed teak is durable, but it's rarely cheap.
To keep costs down, look for simple modular designs, buy from local makers or secondhand marketplaces, and check the warranty and recycled content. Avoid ultra-cheap resin furniture that feels hollow or has thin walls. The best value is usually a plain bench or chair with thick recycled HDPE slats, a sturdy frame, and replaceable parts.
So my budget pick for urban outdoor spaces is recycled HDPE outdoor furniture. It's not glamorous, but it's durable, low-maintenance, made from waste plastic, and practical for real city balconies and patios—which is exactly what low-maintenance patio furniture should be.