House extension roof

330d

I need some advise on a house extension I am trying to plan. Some background;

- House has previously had a side single storey extension.
- We are planning on building on top to create 2 extra bedrooms.

This is the current layout;


As you can see the existing side extension 'kicks' out 1 metre from the rest of the house. My question is, the new extension should it;

- Follow the existing line of the house and build here
- Or build directly on top of the current single extension as shown here;


The architect said it would be better to build to the existing line for a seamless build. But the builder is suggesting build on the current single extension. As this would create more space and how much more work involved.

My main concern is, if I went to this approach would the new roof seamlessly match the old one? Or would there be a step? 


Apologies if I have not explained this well!

EssexExile

If I understand what you are saying, a plan view would help, if the new build first floor is deeper than the existing first floor then the roof will be different. Either:
It will come down further at the front,
It will go higher than the existing roof or
It will be at a different angle to the existing roof.

330d

Thanks. 

If the roof did come down further would that not cause an issue with the window? Like get too close to it?

Ideally I dont want the roof angle to be any different than that of the existing,

DevilDamo

You or your architect also need to familiarise yourselves with your LPA’s sub-servience rules and guidelines.

If you were to build on top of the existing extension, a rear facing gable roof could be designed or failing that, introducing a small dormer for the window but bear in mind the rear part of that room would have restricted headroom. These are options your architect should be providing.

If you were to build on the lines of the original house, a beam will be required to pick up the new first floor rear wall. Again, something your architect should know and make you aware of.