A greenhouse usually houses items like gardening equipment and pesticides, etc. that could be dangerous in the wrong hands, particularly young children, so it is best to keep the greenhouse locked whenever you are not using it.
Greenhouses are designed to create an ideal atmosphere for plants to grow by retaining light and heat, however, good ventilation is also needed to prevent greenhouse air from becoming too stagnant and humid. This would, not only make it too hot for plants to grow, but also create conditions for fungi to thrive.
To avoid too much moisture in your greenhouse which will encourage insects and harmful pathogens like mold, make sure you immediately fix any leaks that have developed.
Additional heating is often required in a greenhouse during the colder months. To avoid the risk of fire or other related safety issues, if you decide to use an electric heater for this make sure it is designed for outdoor use. As an extra safety measure, unplug any electrical appliances when not in use.
Yes, by taking the time to keep your greenhouse well maintained you will contribute, not just to a better environment for yourself, but one for your plants as well.