hi i am going to build a conservatory 4200mm x 3000mm i have to dig out the foundations ready for the concrete what depth and width should i go to for a 600mm dwarf wall to go onto? thanks

As you have so little knowledge at this early stage how do you expect to complete such a project?

Are you doing strip, pile or raft foundations? Is it on made up ground? At the end of the day its dependant on the ground conditions, are there any trees or conifers close by? No one can really give you an answer without seeing the site or whats under the surface. Building control will have an idea of conditions in your area and will be able to give you solid advice

if you are carrying out to regs then 1m ,if not 500mm-750mm will surfice as long as ground conditions suit at that depth,ie not spongey or wet

As stated by substructure,ground conditions will decide on what depth is suitable.It may be that 1m is a bit too much but i would go to this anyway.Much easier to go a bit over the top with the digging than it is to sort out an insufficient foundation once the conservatory has been installed.As for width,you should aim to have around 3 or 4" of foundation either side of the brickwork.

Hi. As substructure says if its work under building regs then 1m is your minimum. I usually do 1m as best practice but 750mm would probably be deep enough as long as the ground is solid at that depth. Rick

Get someone who knows what they are doing to do the job. It’ll be done right and in half the time you will do it. If the founds are off then you’ll chase it up the building. Post your job on this platform and you’ll find the right firm for the job. Is the ground hard clay, sandy clay, sand, earth??? Don’t undermine your existing founds of house and frost level I where I am is 400mm. Usually 600mm min from ground level with 600mm wide found poured 200mm deep with steel mesh in with at least two squares overlapped on cuts. If this is your first venture in founds then don’t don’t attempt it. Pay someone to do it and enjoy your conservatory when it’s built correctly by a tradesman