New Porch Extension With WC

PoGee

I hope my drawings make sense; lower one on each page is what I'm thinking of doing. We really need a downstairs W.C. 2 options are either under stairs but the under stairs bit encroaches into kitchen so I'd lose out on kitchen space (approx 1m by 2m) or build a back porch. I would keep the back door as it is, to keep the WC separate from kitchen. New back door would be onto new decking, with steps at side to garden area. 
How much would it cost to build a 1m by 2.3m extension with W.C?
Is 1m by 1m enough of an area for a WC (I'd get one of those toilets that have a tiny sink on top of the tank)?
Can it be built on brick 'stilts' - (the drain blocks sometimes and need access to it)?
I'm conscious of there being too many doors in a tiny area so would it even work?

Any ideas would be welcome and appreciated.

macman

You haven't stated the most important thing, which is where the existing services are. You need to run in hot and cold supplies, and most importantly the WC waste: extending that can be costly.

PoGee

Waste from existing bathroom goes into drain highlighted so thought that would be one problem scored off. Hot and cold supply in kitchen approximately 1.5m away from proposed WC. I'm a novice so there will definitely be things I've not thought about. 

Section62

PoGee said:

Can it be built on brick 'stilts' - (the drain blocks sometimes and need access to it)?

There's a lot of potential problems with your idea - but this one stands out.  The simple answer is "no".

If there's a drain which needs access then it needs to be relocated rather than being built over.  That could add a significant amount to the cost of your project...

Buildings also have three dimensions, so it isn't easy to judge the feasibility of a project without seeing the space in context, rather than just looking at a plan.  Some photos are essential for people to give you ideas.

FreeBear

macman said: You haven't stated the most important thing, which is where the existing services are. You need to run in hot and cold supplies, and most importantly the WC waste: extending that can be costly.

One only needs cold water - A small instant water heater can take care of the hot feed. But that requires a suitable electricity supply (power would be needed for a light).

Foul sewer is located (almost) directly below the proposed extension - Building Control would need to sign off on a new connection along with the rest of the work. The plans also show decking - If this is more than 300mm above the existing ground level, planning permission will probably be required.

PoGee

Basic query re stilts - there are images on google where people have build 1st floor extenstions over their driveways so that they have a carport underneath. I could extend the extension to 1m by 3m so that the stilts were well away from the drain. It would just mean 1m X 0.7m of driveway being used. 
Is the porch/WC idea any different to 1st floor extensions on stilts?

PoGee

Or could add the 1m by 3m extension (on stilts, if possible) to increase kitchen area, remove old back door and back wall (kitchen), steel beams etc...and use the under-stair area for the new wc. New doorway to kitchen would need to be built. 
There's plenty of space for this at the front porch but the idea of visitors hearing a toilet flushing isn't appealing. The extra wc would be mainly for night-time as son's bedroom is right next to present bathroom and says he gets woken up when rest of family use bathroom. He has an early start in the mornings.

Section62

PoGee said:

Is the porch/WC idea any different to 1st floor extensions on stilts?

Yes, because a raised 1st floor 'extension' is high enough that people can do whatever they need to do underneath.

Also, because the additional cost of that form of construction (structure, insulation etc) is worth it to achieve a parking space and (bed)room above.   Doing the same for a 1m x 1m toilet (only), not so much.

sew_what

1m x 1m is very small for a loo! 

Rosa_Damascena

sew_what said:

1m x 1m is very small for a loo! 

Agreed, a standard sized will project 600mm which means a bit of contortion to use the facilities if you're a reasonable height. I very rarely use my en-suite toilet for that reason: 1m is a squash for anyone over 5'8". 

OTOH a 1m width for a walk-in shower is v comfortable.

Slinky

PoGee said:

 The extra wc would be mainly for night-time as son's bedroom is right next to present bathroom and says he gets woken up when rest of family use bathroom. He has an early start in the mornings.

Don't flush at night? We don't.