Front garden excavation for drive

[Margaret dailey]

Hi all,

 

My name in margaret and im 62 and live in walsall uk. I was directed to this site by a friend who is a member, in the hope i can get some advice.

 

Basically, i live in a semi detached house which you can see from the picture i have attached, sits elevated from main road and has a front garden sloping down from the house to the main street.

 

In urgent need of a disability parking space, we have decided to make a car drive in front of the house. 

 

So we have started the work, by removing the brick wall that was at the bottom running across garden, and a tall bush.

 

Now we are slowly excavating the garden in order to make a space that is flat to park vehicles. I dont want the space to be sloping so were digging straight to be flat 

 

Anyhoo, what i wanted help with was i wanted to know how close i ca excavate to the front of the house wall.

 

I was told i would have to leave at least 3ft of garden and then add a retaining concrete block wall going across and  then in a gap between this wall and the garden behind it, pour in concrete.

 

So yeah thats it, just wanted to know how much garden/land i need to retain from the house wall, how far back we can dig to make drive as long as possible.without it risking the foundations of the house, if that is the case.

 

Im not hoping to go right back to actual house wall and dig all of the soil out, just as far back as possible to make drive as long as possbile.

 

Measurements wise,  the width is approx 18ft, and lenght from bottom of garden on the street to the house wall, its about 23ft. But that is obviously being measured standing on a slope, 

 

Thankyou all. 

[Onoff]

Welcome.

 

Can't help ref the digging out questions. I'd be considering a structural engineer's input tbh and a U shaped retaining wall. None of it'll come cheap I bet.

 

Presumably you'll have to apply for a dropped kerb from the council at some stage?

[ProDave]

Yes be very careful. Dig too close to the house without a retaining wall and it could end up VERY badly.  Definitely a case for structural engineer input and I would not expect this to be a cheap job.

 

And don't forget you need permission for a dropped kerb and might need planning permission for the parking space.

 

Stupid alternative suggestion, can you not just get the council to mark a disabled parking bay on the road outside your house?  that seems normal practice here on streets that don't generally have off road parking.

[scottishjohn]

and don,t forget your 12 degree path from parking spot to house entrance --that will be required if you mention disabled access 

NO steps-it will be longer than you think

Edited April 26, 2020 by scottishjohn

[Declan52]

There might also be some services running through your garden, sewer, electric, gas and water that could need to be rerouted.

[Onoff]

I reckon there you'll be looking at a fugly zig-zag ramp arrangement. Money no object would see a U shaped retaining wall and a lift. 

[Ferdinand]

Lots of factors here, including the type of soil and the detail of the foundations.

 

If you have any neighbours who have done work at the front on similar houses, have a chat to see if they know anything about foundations etc.

 

It will not be definitive, but it may be an indication of what yours is like.

As a joker in the pack, do you happen to have a basement or cellar aligned to the front? 

Edited April 26, 2020 by Ferdinand

[epsilonGreedy]

@Margaret dailey I have three questions:

1. Have you looked at the lower grey band of wall under your neighbour's bay window? I ask because I am wondering if it is just a surface render or some concrete reinforcement underpinning. If underpinning then this is a clue that you need to be careful about removing all that soil in your front garden.
2. Do you know the age of the property? I would guess 1890 to 1925. Knowing the age of the property provides a hint about how deep the original foundations are. Some Victorian foundations are way-way less solid than standard building practice today.
3. Have you applied for planning permission? I assume so judging by the notices attached to the lamp post.

@The Forum Collective

 

Could Margaret transgress party-wall regulations if she digs out the front garden to within 3 feet of the front bay wall?

[Margaret dailey]

thankyou all for your advise and help...

 

if i can answer some questions,

 

a disabled parking spot is not an option outside so im not considering that at all.

 

in respect of a surveyor i do not have the funds to be able to afford that. 

 

i have a neighbour who has very kindly offered his help to dig out the soil for me for a small amount. so the digging cost is not an issue. 

 

and as for a u shaped wall, my brother is going to build that for me with blocks as he done this before in his own house.   so hopefully costs wont be too much.

 

it was a little bit soil but now its mostly clay and a little bit sand.

 

in respect of my neighbours, they have just moved in but have now said they want to do the same, they have a little space in front which u cant see in the picture where they park their small clio sideways and then a retaining wall painted green and covered in bushes which you can just about see in picture but not a lot of space for the car to park so they want to dig back also now,

 

im just loking for advise  in regards how much soil/land needs to be left.  i can get all of it dug out, thats not an issue, its just we dont know how far back we can go without it being a risk 

 

so if someone can roughly just say how much in feet we should retain, and then put in the concrete wall right across, that would be helpful.

 

i am of the opinion that we should leave at least 3 ft from bay wall, then put in block wall and then that should leave about 20 ft to the boundary

[Margaret dailey]

[ProDave]

Before you go much further I would do a test dig adjacent to the house to find how deep the foundations are (dig down a small hole by hand and see how deep before the bricks start stepping out wider or you hit concrete)

 

Then you need to apply the "45 degree rule"  Project an imaginary line from the foundation depth down at 45 degrees and that is the soil you must not disturb without proper structural engineer input.

 

If your neighbour is doing the same then you won't need a retaining wall between you so that is some cost saving but you will both need a retaining wall between the parking area and the house, and at the side between the parking area and the path to your front doors.

[Margaret dailey]

thankyou for that advise.

 

but can you simplyfy it for me a little more.

 

im really sorry, im not the sharpest tool in the box, lol but your advise seems great but just a little hard to understand for me.

 

can you please just explain in simpler terms what i need to do.

 

also my neighbour is not going to do theres yet. so i dont know when they will want to put there wall in place

[Margaret dailey]

whe  you say this "I would do a test dig adjacent to the house to find how deep the foundations"

 

do you mean i stand by the bay window and just dig some soil out with my hand and see how far the house goes down,  how much do i dig down?

[Margaret dailey]

also can you explain this please "

 

Then you need to apply the "45 degree rule"  Project an imaginary line from the foundation depth down at 45 degrees and that is the soil you must not disturb without proper structural engineer input".

 

 

[Onoff]

20 minutes ago, Margaret dailey said:

also can you explain this please "

 

Then you need to apply the "45 degree rule"  Project an imaginary line from the foundation depth down at 45 degrees and that is the soil you must not disturb without proper structural engineer input".

 

 

 

Something like this I think he means:

 

 

In fact I've seen places where the slope gets paved.

[Margaret dailey]

again thankyou for your help,  and really appreciate the drawing.  but im still a little confused.  

 

i understand i stand at the bay window then dig down a little until i can touch concrete and then i dont understand what i need to do to work out where to stop digging to.

 

[Margaret dailey]

also it wont end up being a slope, it will be all dug out so the car can park flat.  and not on a slope, so that my car can be driven on and its flat land.

 

one other thing, once dug out, we are going to be putting up walls using concrete blocks.  so one will be putting a wall up between the remaining land in front and either side also,

 

see  poorly drawn pic below.

Edited April 26, 2020 by Margaret dailey

[Onoff]

24 minutes ago, Margaret dailey said:

also it wont end up being a slope, it will be all dug out so the car can park flat.  and not on a slope

 

At the bottom of the slope is where the new flat area for parking will be / start from. How much parking space you end up with is dictated by where the 45deg slope ends. My fag packet sketch is very rule of thumb just to show the concept. 

 

 

Things to consider are leaving a width in front of the house for future access like maintenance and cleaning windows. Similarly you don't want to expose too much of your foundation to weathering by the elements.

 

Hopefully you'll see this is more than just dig it out and hope for the best. You might well need building control approval. If it all go t!ts up and the front wall of  the house develops cracks, subsidence or worse it might well invalidate your insurance.

 

Really not trying to scare you.

 

The only way to cut back fully, to say within 3' of the house is to get structural engineer's input and likely build a big, reinforced U shaped wall. You might even need temporary supports to the house whilst you do. Similarly I'd get an SE even to go the 45deg route.

Edited April 26, 2020 by Onoff

[Onoff]

28 minutes ago, Margaret dailey said:

also it wont end up being a slope, it will be all dug out so the car can park flat.  and not on a slope, so that my car can be driven on and its flat land.

 

one other thing, once dug out, we are going to be putting up walls using concrete blocks.  so one will be putting a wall up between the remaining land in front and either side also,

 

see  poorly drawn pic below.

 

Explains what you want to do perfectly. Really...get professional advice.

[Margaret dailey]

as to my drawing, the walls were going to be building using the blocks, will they be what you have referred to as a u shape wall?

 

and as to a SE, genuinely dont have funds to be able to do that.  if i did i would have. some just relying on help and advise.  

[ProDave]

Thanks @Onoff for the drawings.

 

If you want to to plan this you really need to know how deep the foundations are, then you can draw a drawing like @Onoff did a few posts up but properly to scale with your actual site measurements and foundation depth.

 

If your proposed parking space does not cut into the bit below the 45 degree line, then everything is fine.  If it does, you will need a structural engineer to design a retaining wall.

 

You might well find because the house has been built on a slope that the foundations are already deep.

 

An alternative might be to lift some floorboards in that bay window and see how deep the void below the floor is, that will perhaps give an idea of the foundation depth without digging a test hole.

[Margaret dailey]

[RandAbuild]

Margaret - looking at your photos, that retaining wall could be over 6 feet high. You also have to dig out the foundations for the new wall, meaning further digging.

 

This really is getting dangerous. Anything over 3 feet high needs to be properly designed and constructed.

 

I've just done a quick Google of retained walls and here is one example from Local Authroity Building Control:

 

https://www.labc.co.uk/news/retaining-wall-basics

Edited April 26, 2020 by RandAbuild
Correct typo

[Margaret dailey]

i think i might have confused the point.  on/off drawing showing the side of the house is spot on,  however the current level of the ground is not straight.

 

if you please take a look at my drawing showing the side of the house,  there is no access from the front, the front door is at the side of the house facing the street.  there is a bay window infront of the proposed drive.  then in front of the bay window there is small peice of ground u can stand on which is flat, approx 1ft then it slopes down all the way to the bottom wall at the boundary which has been removed now.

[Margaret dailey]

Randbuild thankyou also for your advise.  ive taken a look at the info about the wall and will definately take into account

 

but can anyone help by estimating how far from the front of the house this retaining wall should be placed.