Declining (sloping) garden

[TSeeker]

We are on the verge of reserving a plot in a new build estate. We liked what we saw in the show home for things like overall space, bathrooms, garage etc. Just as we were about to reserve it I asked for a more detailed planning drawing which is normally shown only after reservation.

The garden seems to have a slope. The back wall of the house sits at 94.75m above sea level. One corner of the garden at the farther end is at 94.20m and the other corner is at 94.30m. So a 55cm (almost 2 ft) decline, going away from the rear of the house. The garden is 9m (29.5 ft approx) long from the rear of the house and 12m wide side to side.

I don't know the size of the patio (the solid/concrete bit) but I'm just assuming that's say 4 feet and that's flat (I'll need to ask that). That leaves about 29.5 - 4 = 25ft (rounding off) over which the slope occurs.

That means 55cm over 25ft which is 55cm over ~760 cm. That is 55/760 * 100 or 7.24% slope. Or if you prefer 1:13.8 gradient. Say worst case 1:13 gradient.

The plot is being built right now so not accessible and I don't have any gardens around where i live with an incline like that, that i can view and see what it looks like.

The good thing is it at-least slopes away (and faces north if it matters), so we won't have rain water channeled towards the house.

The bad bit is I don't know what to expect. Does anyone here have experience with that kind of gradient? Does it cause the soil to wash-away gradually, more upkeep? Mowing the lawn with that kind of gradient? How awkward or not would setting a garden table be when the weather is good and we want to enjoy sitting outside?

I also don't know if building a shed or a decking area will be more difficult/expensive in that kind of a setup (I'm birdbrained when it comes to engineering lol).

I'm suspecting it's not terribly steep to be put right off but not flat too which I'm normally used to. The house otherwise ticks the boxes. Just looking for advice or caveats if anybody has any for us.

Ta!

Can't they just level the garden as part of your negotiation?

Impressed with your number work btw. Almost, almost as good as a diagram!

Should add, it's a detached house, currently with only side neighbours and nothing (so probably a future building site) to the back (just normal grassy area).

Beyond the rear fence, the area sharply declines meeting some sort of a (very) small/narrow stream and then rises again, creating almost a miniature valley of 5m in height. Probably means we won't have neighbours very close to the rear of the house in future.

Can't they just level the garden as part of your negotiation?

I've asked them to do that and the site manager is on a holiday so need to wait until next week to get a response. Given how desperate ppl are to buy plots here, I suspect they could sell it off even over a nuclear waste lol. So won't be surprised if they just say a categorical "no"

I'd be more worried about the stream and flooding risk.

We looked at a house with a stream in the garden and rang our current buildings insurance company to get a rough quote to insure it. They refused!

Especially with new build (why were no homes built there before?) You need to check the flood risk in the way I describe above.

There is also some kind of nationwide map to check this via postcodes. I can't remember how to find this. Sorry.

I'm thinking that as a new build you may not be having a full survey? If you are, please ask the surveyor about the stream.

We bought a new build and the back garden sounds very similar to yours - wide but short, with a slope from 1 corner near the house to the opposite diagonal corner. We estimated the drop to be approx 2 ft. We chunked the garden into 3 and levelled each one but on different levels. So the patio which came out from the kitchen is flat with steps leading down to the middle section grass and flower bed area, then the final third is higher with a terrace and seating areas.

It wasnt designed to be child friendly! I love it - there is interest. Our builder paid for the digging out of the middle section as they had done a shockingly poor job of removing the underlying rubble.

I had to have the fence replaced recently - I kept it flat across the back and the side fence slopes down.

New build sites are often built with decent consideration of flood risk, but worth checking

flood-map-for-planning.service.gov.uk/

My garden slopes. It’s about 30 m long. It’s 2 metres higher at the house end.
Ours was terraced by previous owners and that works well for us.

I would be far more concerned about the stream. If it’s a new build then you have to wonder why the plot wasn’t built on before.

They are building new houses near my parents. Everyone in the village knows the field floods regularly but the are building anyway. The river is a small stream until it rains heavily and then it very quickly bursts its banks.

Our garden slopes down towards the house with a 4 ft drop. Our children loved it and used to ride down the slope on anything that had wheels. We’ve never thought of it as a problem. The last 20ft was flat so we had somewhere to put the paddling pool.

Thanks all.

For the flood we did check the flood map and it's OK. There's a small patch near our plot with surface water "medium" risk, but nothing else. As for the stream, it's actually dry most of the time. There's a defunct reservior next to the building site one side. It's been dry (rather intentionally drained off by the govt) for decades now. The "stream" was basically a drain away for the water from the reservior when held water. Now it's just a channel for the rain water whenever there's heavy rain. The flood data also show there hasn't been any flooding in near history. Still, would not discount the possibility ofc.

For the 2ft drop over 25ft garden (assuming patio is flat and 4.5ft in width and the slope starts after that), I suppose it's not going to be too great for picnics. However I got a long plank from a broken garden fence nearby and created a 1:13 slope. The glass tumbler's holding up well unless filled to the brim (probably raises the centre of gravity high enough to make it really unstable then).

That's the biggest experiment I've done since high school lol.

Gosh feels so bad - everything's fine and then there is that one problem that had to jut out. Thinking about sucking it up and just going for it! Somewhere a voice tells me don't, though. Just means we spend even longer renting or hoping an equally nice property for the price comes up soon :(

if you have to, you can terrace it to have flat bits with little walls between. As a pp said, it can make for a nice interesting garden.

I wouldn't worry about it too much.

I agree about terracing. You put in a retaining wall to hold the patio in place and then build steps down to the lower section which you need to be levelled. 500mm isn’t that much. Two steps! Yes it might be beyond the builder but I would get this done so you have two usable areas. Slopes are not great.

Make sure the slope is retained where it meets the stream banks.

All new builds have to submit schemes to absorb flood and surface water. These might be planted “ponds”. The local authority planning department should have details of what has been required on the planning portal. DH’s company designs these for developers and they do not just build on flood plains without substantial works to absorb the flood water. The Environment Agency is hot on this and they do know which areas flood. Locals always think builders are stupid but do not realise environmental engineers have designed schemes to prevent flooding.

Here is my garden with terraces. One from the top and one from the bottom.

Where?

www.mirror.co.uk/money/couple-who-bought-dream-first-23960278.amp

This looked a complete nightmare

@TizerorFizz

Where?

Oh sorry. They didn’t attach for some reason.

Try again. My terraces from the bottom of the garden.

I don’t believe the home owners in The Mirror story didn’t know anything was wrong prior to trying to sell it. The gabion has collapsed for a start. I wonder if they ever saw the approved structural designs for the gabion baskets as they are, effectively, a retaining wall for the house and garden. It really is a case of getting a structural survey when you buy if there is a retaining wall involved!

I have almost exactly the same drop over the same distance. Been here 17 years and no issues. We've sort of terraced a few levels on a strip down one side to make a deck, a seating area, a summer house base, hot tub base etc but otherwise its just grass. No damage over that time and you hardly notice it day to day. We've camped in the garden and had pitches elsewhere with a worse gradient!

Our garden has a downward slope towards the house, and because its extended the steps from the bit they dug out (which is now a patio) is a significant drop to the rest of the garden. We just added some water grates and added a pebbled path to absorb some rain water. Never had a problem with flooding just ensure you have good drainage and somewhere for the water to escape to

@motherofawhirlwind and how much would you say such a terracing costs approximately? Also did u have access? Ours would probably not have any, once the houses are completed and ppl move in. So I guess it'll be even more labour intensive.

My OH did it himself in stages over the years so just the cost of the materials. Sorry!

Hi OP, we have a very similar garden, and so far (fingers crossed!) flooding or water run off has never been a problem for us. I don't mind the height difference as such, but we would like to get parts of the garden terraced- the slope is a complete pain to mow, and if I climb a stepladder to trim any plants back it can be fairly treacherous. We've been advised that terracing can be very expensive sadly, so you might want to bear that in mind. We've done tiny bits of levelling up in our own garden, but its pretty hard work. I'd push quite hard for the developers to do it if you can, whilst they're still working on site and have all the digging equipment there. The other advice I've been given to keep costs down is to terrace just part of the garden, so flatten and level part of the garden for a lawn, another part of a patio, and disguise the slope in the middle with some clever planting.

North-facing though?

@Reizal I see. So you had 1:13 too I take it.

I did ask them to level it. They came back saying many of the houses there had sloping garden and this is one of the last plots left so there is no way they would level it given ppl wiil buy it anyway. They however decided to let us take a look at another plot, sold, more complete and accessible with lesser safety concern. They said that's even steeper so would give us a feel. But they wouldn't level it.

I'll try decide once I see that other plot. It's so difficult - miss it and you sit a long time for the next in-budget one. Take it and you might miss a flat garden.