At the moment it is an old pre-fabricated concrete panel construction job with metal roof trusses and a cement/asbestos corrugated roof. The whole thing can be unbolted and disposed of.
The walls to the garage currently sit on a sound, 8" solid concrete slab with hardcore (probably built sometime after the house which is 1930's).
The size of the garage is 2.63M wide x 4.67M long.
I want to build a new garage on the present foundations without having to excavate down to support new walls/roof etc. seeing that the old garage with its roof and walls has stood the test of time and not moved or cracked under its present weight. The new garage will be higher - in line with the house extension roof - 4M high with a flat roof and adjoined onto the extension wall. The front of the garage has been finished with a facade with a pitched roof and supported by a steel post and beam construction, this was done when the extension was built onto the side of the house 10 years ago. The old garage is integrated into the rear of this construction and looks horrible, although the builder did a good job and no leaks have occurred over the past years. Suggestions on construction and modern lightweight materials with thermal qualities would be welcome. I plan to use the new garage as a workshop/garage and would like some form of insulation in the materials used. Is this possible or am I asking too much?