You can add a roof to most decks, but you need to have it inspected first. If your deck didn’t come with a roof initially, it may not be able to handle the weight without some structural changes. You can add additional supports to your existing deck to safely add a roof, and tying your deck’s roof to an exterior wall can help add some structural stability, but remember these aren’t DIY projects and need to be left to a pro. 

With proper installation and maintenance, a vinyl deck can last up to 30 years. Factors like regular cleaning, minimal wear and tear, proper installation, and the use of higher-grade materials can extend its durability. However, extreme weather conditions or neglecting maintenance might shorten its lifespan. Adhering to manufacturer recommendations for care and occasional inspections can significantly prolong a vinyl deck's longevity.

Composite decking might cost more upfront, but it delivers value in terms of durability. Unlike wood, composite material resists common deck problems such as rotting, fading, warping, and all the other things you don’t want a deck to do. The extra processes lead to a higher price tag, but you’ll save big in maintenance costs down the road.

A sunroom will add more value to your home than a deck, but with a much higher up-front cost. Depending on its construction and function, a sunroom may be counted as additional living space, while a deck is strictly an outdoor feature. Both will increase your home’s value, but the sunroom will have a much bigger effect.