Rank amateur questions about a new bp driveway

[CBPPEnthusiast]

Hello all,

I've searched the forum a little but because I'm brand new to all of this, I suspect my google-fu is weak; my search-terms are probably not accurate and I'm not seeing the answers I (think I) need. Your help would be greatly appreciated at this juncture.

I am getting a new drive-way for my house done imminently. In the interests of keeping costs down and expediency (read: I'm cheap and lazy), I'm attempting to do this under permitted development law. However, there are some nuances to my situation which I'm not sure have a bearing on using 'permitted development' law or not.

The proposed drive-way is for a semi-detached house, and will utilise the whole of the front-garden as it currently exists now - somewhere in the region of 25m2. The current 'garden' consists of impermeable paving and concrete throughout. The plan is to remove all the existing concrete and paving, and install a Concrete Block Permeable Paving drive-way in its place. However:
1) Is installing a CBPP drive-way right up to the edge of the house recommended? Are there any issues with doing this?
2) Because of where the damp-proof course is in the house wall structure and also because of the height of the air-vents in the wall (house built in 1939), the drive-way will have a shallow slope towards the house. Whilst I think that there is no inherent danger of installing a CBPP drive-way with a shallow slope towards the house so long as the base layer is level, should I also install a drainage channel near the house for overflow requirements?
3) If a drainage channel is recommended, said channel would be connected to the sewer itself (along with the roof guttering). Are there are any planning concerns with doing this, assuming the rest of the drive-way uses CBPP?

The house is in northern Surrey, so I'm fairly sure the local planning authority (Elmbridge) will be quite keen to know what I'm proposing given the area's history of flooding. I don't think I can get away with impermeable paving and a soak-away, as I suspect there is no appropriate position for a soak-away given that anywhere in the front-garden is likely too close to the property itself.
I can provide images and precise dimensions on request, although this would have to wait until the evening of Monday 8th as I'm not yet living at the property. Any assistance you can provide would be great! Thanks a lot in advance.

[lutonlagerlout]

IMHO
fit a linear drain along the front of the house running to a crate construction soakaway under the driveway using normal CBP
permeable paving has so many vagaries and is much more expensive to install
as long as you have this drain/ soakaway combo its all good
cheers LLL

[rxbren]

If it has to fall to the house install a linear drain along the front of the house, don't have any level/flat areas as it will pool water. Pipe linear drain to suitable soakaway/storm drain

[lutonlagerlout]

great minds Rxbren and all that :;):
LLL

[rxbren]

just seen both at the same time lol

[Hairs]

This is a similar build to mine at least you know the sub grade is suitable for paving as there is one there already. I'm planning channel drains and large soakaway under permeable paving. I have a French drain then crazy paved area in front of my house and then a channel drain.

With a 25m2 plot the soakaway could possibly reach 5metres away but what use would a channel drain be with permeable paving as the water wont be on the surface it will be in the sub base. Ohh I see using the channel to drain the roof, if your paying for storm water to be removed then connect to the sewer. I'm not so I've gone with the soakaway option.

[Tony McC]

1) Is installing a CBPP drive-way right up to the edge of the house recommended? Are there any issues with doing this?

2) Because of where the damp-proof course is in the house wall structure and also because of the height of the air-vents in the wall (house built in 1939), the drive-way will have a shallow slope towards the house. Whilst I think that there is no inherent danger of installing a CBPP drive-way with a shallow slope towards the house so long as the base layer is level, should I also install a drainage channel near the house for overflow requirements?

3) If a drainage channel is recommended, said channel would be connected to the sewer itself (along with the roof guttering). Are there are any planning concerns with doing this, assuming the rest of the drive-way uses CBPP?

1 - CBPP can be laid right up to the house. If you so desired, you could lay a narrow-ish strip (<1m) of conventional paving against the house and then rely on its fall towards the CBPP for drainage.

2 - Not sure why you think the sub-base has to be level. It can (and should) follow the profile of the final surface so that you get a uniform depth of laying course grit.

Some designers do like to include a linear channel at the lowest edge of a permeable pavement as alleged 'insurance' in case there was a huge downpour. If the CBPP is properly constructed, there is no way a downpour could cause surcharging: the pavement would/should absorb it all.

Even if you have a downspout discharging, there is still no need for a linear channel. The downspout can discharge straight onto the CBPP and the Type 3 sub-base will deal with the water.

3 - that's just over-complicating matters. While it would be within PP consent to collect roof discharge and divert it to the SW system, why would you when you have a stonking great soakaway right there beneath the driveway?