Most garden offices, apart from the self build options are sold as fully project managed services, known as ‘Turnkey’ projects, this offers you the customer peace of mind because your supplier will handle everything for you, and you can just sit back and watch the building take shape.
In some cases a supplier will have expected you to clear the site from vegetation before they start work, other suppliers may ask you to organise the installation of the foundations and they will handle everything from there upwards.
If you do need to organise the foundation system yourself, you will be given drawings and measurements, and a suggestion of the foundation make-up to guide you. Organising the foundation normally requires you engaging a local builder who will excavate the site and install the foundation.
A common job left to the client is the connection of the garden offices electrics to mains supply, this needs to be undertaken by a certified electrician and not all suppliers send one to site, but your supplier will make it clear if this is a task you need to organise.
Other jobs we have heard the customer can be left with is painting the interior walls, some suppliers use an unfinished internal lining so the customer can make their own mark on the internal space.