Renovation prior to extension

[jayc89]

We've had approval through to extend our house. Given the current climate, we've decided to focus on the renovation of the existing property rather than extend right now, with a view to extending in a couple of years (getting the foundations in just before the planning expires).

 

With that in mind, we want to crack on with the renovation but are keen to ensure whatever we do now isn't wasted when we do eventually extend. This is the approved planning application, I have drawn the red lines on to show where the existing external walls are.

 

 

What is labeled as Kitchen/Dining is our existing Kitchen/Dining area, the kitchen is solid wall, the dining has a small cavity. The full lot is a concrete slab, which we don't believe is insulated, so the plan is to replace that and lay UFH at the same time. The purple dotted lines are structural supports, so we're considering putting the beam in across the kitchen/diner now as to not have to disturb this area of ceiling again later, if possible

 

Where the Boot Room/WC is proposed, is what we currently use as a dining room, there is hot and cold water supplies over head, so they are simple to tee into, but there is no foul waste on the south elevation. (The existing kitchen waste is on the south elevation, which we believe goes into an old septic tank)

 

Upstairs, there's currently no ensuite for bed 1, that space is part of bed 3. The dressing area in bed 3 and ensuite area in bed 4 are both currently the dressing room/ensuite for bed 3. 

 

In terms of reshuffling the rooms, its all relatively straightforward, I'm thinking we can make it look pretty much as the plans, apart from the ensuite which would be part of bed 4, that would need flipping around (sink/toilet/shower on external wall) whilst it's still accessible by bed 3.

 

My biggest unknown is drainage. We need a new run of foul drain to Bed 1 Ensuite, Bed 3 Ensuite, what would be bed 4 ensuite and the downstairs W/C + kitchen. Joists run front to back, so I can run a length under the floor in bed 3 and cap it off ready for use later, but given what would be bed 4's ensuite will eventually become an internal wall, I'm loathed to run the downpipe externally (I'd prefer everything was hidden internally and vented to the cold loft space anyway). What would be the best option?

 

The mains manhole is to the North-West of the property (near enough where the bottom-most "Lawn" text is) and not particularly deep (CL 3.44m and IL 2.76m), so I'd need to lay a fairly long run for anything coming out of the house on the South elevation, hoping I can achieve the required fall without a pump. 

[jayc89]

I should have included a copy of the existing floor plan too...