taylormsj

Hello, We have had a rear extension completed with external wall rendering and now I'm planning the patio outside. We have rainwater sewer access at each corner of the extension so my plan is to run an ACO drain butted up against the external wall along the whole width of the wall. The patio would then fall towards the house so rainwater is collected by the ACO and run into the rainwater sewer. I have attached a mock up, showing the building, DPC and our desired patio height. I asked our building control officer about how high the patio could be in relation to our internal floor and DPC. She has come back to say that the regs say 150mm below DPC, but there are work arounds with this when you have external render on the walls and ACO drains. However, she has said that because we have a timber suspended floor, the patio height can't actually exceed the concrete base that our floor sits on (as demonstrated in the drawing attached). The reasoning behind the patio not exceeding the internal concrete base is that water will naturally pool internally if the external ground level is higher (although I'm not sure how if the drainage is properly installed). This will result in quite a high drop between internal/external floor. My question is - are there any solutions around this to avoid such a steep drop from the house to the patio that will also satisfy building control? Our BCO has generally been very good and helpful so far, so I'm not sure if she was simply answering my question about my proposed solution without giving me an alternative, or if there actually is no alternative solution. Thanks for any help or advice.

Thanks @Temp @joe90 So to summarize (with the help of the drawing below - red is neighbour's existing extension, green is proposed new extension) I only need to serve notice of excavation to neighbours 2 and 3 if the foundations are to be deeper than theirs. I don't need to serve notice on the line of junction to any neighbours If we wanted to build the wall on the line of the fence, we would have to serve notice on the line of junction?

Thanks @Temp that's really helpful. So we only need to serve notice for excavation if the foundations are to be deeper. Do we need to serve notice of line of junction?

The wall sits pretty much bang on the boundary line. There is guttering. The current conservatory (to be removed in favour of new extension) is using the extension wall as it's own.

1000mm has been indicated at the moment and we're not sure how deep the neighbours' are. Digging a test to find out is an option. We're on good terms with the neighboards, is there any harm in serving a notice if it's not needed (assuming they wouldn't dispute the notice) The existing extension on plot 2 has been built up to the boundary, pretty much on the center line of the 2 houses. So it sounds like this is a party wall. When you mention tying in, do you mean building the wall next to their and using brick ties? When I mentioned the fence, I just imagined that it we went up to the boundary line it might look better for the fence to start at the end of the extension wall, rather than the neighbour have a fence up against a brick wall in their garden. I suppose this is something to discuss an agree with them, as long as we stick to the boundary line. When you mention practical reasons to build a foot away - do you mean practical in the sense of building, or less hassle with the neighbours and PWA? Good point. I never noticed a building in their garden but I can see an outline on the drawing. We're not moved into the property yet, but I will check next time we are there. If it is a building, I suppose we would need to server a PWA notice for excavation (if foundations are going deeper)? Thanks for taking the time to respond

Thanks @joe90 This is a garage which is attached to our garage.

Hello, We are planning a 4m rear extension. We've had the plans drawn and now we need to consider if we need to serve any party wall notices. I have done some research and spoken to a surveyor who gave me some advice over the phone. I've attached a drawing of our plot below. Our house is number 1 and the proposed extension is indicated by the box with diagonal lines out the back. From my understanding we will need to - Neighbour 2 - Serve notice for excavation and line of junction. The extension wall will run alongside their extension wall and then their fence (potentially removing part of their fence) Neighbour 3 - Serve notice for excavation and line of junction as their garage is adjoined to ours and the extension wall will run along the end of their garden boundary Neighbour 4 - Serve notice for line of junction as the extension wall will run along the end of their garden boundary We'd be really grateful for any insights or advice anyone can give.