Hi all,

I'm planning the footings for our self-build conservatory and need
some advice.

I have dug an investigatory hole to see how deep the house foundations
are. The house is a 1980s 2 storey detached. So far I have (from DPC
down over) three courses of brick followed by three courses of blocks.
I haven't managed to dig any deeper yet because the small area of the
hole is making it rather difficult. Assuming that there are 3 courses
of blocks + 3 courses of bricks that is about 900 to dpc plus I guess
about 250m of concrete for the footings. DPC is about 2 bricks height
above ground level so that leaves a dig of around 1000.

To be as safe as possible I guess that my conservatory foundations
should match the house foundations in depth and construction.

I'm wondering whether this is going to be overkill given that the
conservatory with 600 dwarf wall is going to be much lighter than the
house.

I will be doing all the work myself. If the foundation trench needs
to be 1000 deep to match the house then the conservatory of 3400 x
4000 with a trench width of 450 is going to entail digging away 4.725
cube of earth! Clearly that is quite a lot and if I can safely keep
the foundations shallower then that would be great!

I notice that picture 3 on
http://www.conservatoriesonline.com/construct1.htm shows a foundation
trench where the blockwork foundations of the main house can be seen
thus indicating that the main foundations are much deeper than the
conservatories. Is this acceptable practice?

Would anyone care to comment on whether I am taking on too much work
for one person here. In addition to the digging for the foundations I
will need to strip off some topsoil in readiness for the hardcore, I
will have about 1 cube of concrete to mix and pour for the footings,
about 1.5 cube of hardcore to move and compact, blinding and
insulation to lay and then another approx 1 cube of concrete to mix
and lay for the floor, not to mention the brick laying. My QS pal
recons that's about 2 weeks work for 2 big lads. I thought that
seemed a bit over the top.

Any thoughts, am I mad to even consider it?


Thanks

Mike