Super economical in garden landscape cost terms, attractive and highly desirable for most, the % of your garden space laid to lawn will dramatically impact the final cost/m².
Seeding is less expensive than turf, and the grade of turf chosen for your lawn further varies the cost. With those branded as hard wearing or weed-free being more expensive than the basic general-purpose variety. As ever preparation is key and costs including preparation and laying the turf vary between £10 and £30/m². Complications encountered can further add to this amount, examples of these being, taking up old turf, the addition of new topsoil if the existing is of a poor quality and access arrangements to the garden.
Other surface coverings
You might also want to consider loose gravel (low cost) rate / m²or resin bonded gravel (high cost) rate / m²