conservatories have a name of being expensive, but if you compare them to a regular extension built onto your home then, per square foot, they can work out a lot cheaper.
See prices here: Conservatory prices 2020 | How Much Does a Conservatory Cost?
A Conservatory for Extending Your Home

view the conservatories in situ at the many Trade Fairs and home exhibitions which run constantly throughout the UK as well as using online options which will explain every detail from the construction, costs involved, the installation process, features, styles, options and average prices.