House extension

[williamglossop]

I'm planning a two storey side extension. Currently there is an attached garage at the side. I want to remove this, rebuild it wider, put a bedroom and en suite above it and create a dining room at the back. I've attached pics of the existing and proposed plans. The house is built in imperial size pin hole brick.

The planners have agreed that I don't have to set the new build back and can have a continuous ridge line. Ill be replacing the existing roof at the same time so it all matches.

The front elevation is going to be rendered (above the ground floor windows). The gable end is going to be brick.

Where the new first floor front elevation joins the existing, what's the best way to join new and old, given its being rendered over.... Toothed in or wall starters? Will the join between new and old cause cracking in the render? Is there any reason to use anything other than imperial Common concrete bricks for this area, given that its being rendered over?

 

[Bonni]

The house and extension are on two different foundations so never tooth in, the join will always crack.

So put a render bead on the join. Also, you could move the downspout over the joint.

 

[williamglossop]

Thanks Bonni. Just out of interest, when would u tooth in? Aren't extensions always built on separate footings? Good idea about the down spout too.

 

[Mag2.0]

Hi Williamglossop,

In my area, recent builds which are toothed in are always single storey buildings. So I think the answer may be lightly loaded structures where the risk of long term settlement is reduced.

May I ask, are you a detached or semi detached property?

 

[williamglossop]

Its link detached, ie next doors garage attaches to my house on the right. My garage is on the left and is not attached to any houses on that side.

 

[panlondon]

I have built something similar, old house was solid brick construction, new extension is aircrete blocks with insulated 10 cm gap in the middle. it was joined with standard brick joiners, a metal plate basically. No issues whatsoever and no cracks even though aircrete to my surprise look fragile. if you have bricks then I expect the tooth in should be stronger.