house alteration costs.

Hello all, having looked at previous threads, nothing seems to answer my questions, so please can anyone help with this :
I've recently moved to a 1988 house. It has a "breeze block" inner wall and a brick outer. I want to extend it by building over the single story garage, utility room and toilet . The total area is approx 2700mm by 8200mm and would contain two rooms, a bathroom and bedroom. I would like the builder to reuse the apex rooftiles on the garage (the utility room has a flat roof) on the new apex roof over both new rooms, with extra new tiles to cover the shortfall. I should require both rooms finished to plaster/electrics/soil and supply pipes only, I will fit out the bathroom suite and decorate through. The landing window can be transferred to the bedroom, (as its good quality UPVC and only 1 year old) there fore only one window is required for the bathroom. For the time being this can be of the single glazed balsa wood type.
(there is an issue of light here,I might decide to have a landing between the new rooms with an opaque window in loss Vs. light loss......unsure at the moment)
Soil pipes can be accomodated easily by dropping through to the down stairs toilet. I will box it in. Electrics can easily be accomodated, as can water/central heating.
Further work involves converting the garage to another reception room. this will involve raising the floor height by about 150mm, replacing the door with a front wall/ window,(heres the nasty one) moving the consumer unit to the pantry( can this be done? does the consumer unit have to be on the outside wall? the meter in in a plastic box on the outside wall of the garage), and plastering the garage walls which are bare breeze blocks. Lastly, a new 3000 by 4000mm garage using the old door, with an apex roof.
As far as I can see, the foundations of the single story area are constructed in the same manner as the main house. The only drainage/foul water issue is the new garage roof. This will require a trench of about 3000mm to a stormwater manhole.
OK I know and realise this is not DIY in the strictest sense,but some of you folks may have an idea of how much this is going to cost me. I live in Staffordshire. Would it be better to move :-)
thanks once again,
Add pictures here
<% if( /^image/.test(type) ){ %>
<% } %>
Add image file

Site Timeline is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.