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The money

What a garden really costs — and what AI can honestly save

We found defensible ranges for design and build work. We did not find evidence that AI saves homeowners money. This page keeps those two truths side by side.

8–20%

Designer fee range

of build cost across published UK sources

£3.2k–£8k

On a £40k garden

the same range applied to one example

Unmeasured

Proven AI saving

no credible net-savings dataset found

Market prices

What does the market actually charge?

The market can price design and construction work. It cannot yet price the effect of AI, so the source record and its limitations stay visible.

01 · Design fees

How much does a garden designer cost in the UK?

Published UK figures run from 8 to 20 percent of build cost. On a £40,000 garden that is roughly £3,200 to £8,000; hourly work is quoted at £50 to £200.

Source limitation

There is no disinterested source: no Which? report, trade-body survey or official dataset. Every figure comes from a paid directory or a design practice publishing its own prices.

Full evidence ledgerOpen all 7 sourced design-fee records

Percentage of build cost

10%–20%

CheckatradeUpdated June 2026

Read the source note
“A garden designer will usually quote you based on a percentage of the complete garden renovation - usually 10% - 20% of the build.”

Commercial interest: Paid trade directory. Trades pay for membership and leads.

Percentage of build cost

8%–20%

Older figure

Phil Hirst, garden designer, via Houzz UKMarch 2023

Read the source note
“Clients should expect to pay between 8% and 20% of the overall project budget for design”

Commercial interest: A practising designer describing designer fees, on a designer-listing platform.

Percentage, sliding with size

18% at £10k → 12% at £60k

Ernest & Edward Garden Design, DurhamNo date published

Read the source note
“% designer fee varies from approximately 18% for a £10,000 garden (i.e. £1,800), to 12% for a £60,000 garden (i.e. £7,200).”

Commercial interest: A practice publishing its own fee scale. Transparent, but it is their own price list.

Percentage of build cost

15%–18%

South Hams Garden DesignNo date published

Read the source note
“The garden design costs (payable to garden designers such as ourselves) make up typically just 15-18% of the overall cost of creating the final, fully implemented garden.”

Commercial interest: A practice justifying its own share of the budget. Note the word “just”.

Hourly rate

£50–£200, averaging £125

CheckatradeUpdated June 2026

Read the source note
“Some, however, may quote you on an hourly basis for their time - averaging £125 per hour.”

Commercial interest: Paid trade directory.

Fixed fee, full layout to scale

£1,250

Jane Eastwood Garden DesignModified June 2026

Read the source note
“Full layout design drawn to scale ready to give to landscapers or other contractors”

Commercial interest: A practice publishing its own price list. The clearest per-package breakdown found.

Where the fee goes

Drawings are 40% of it

DP Garden Design, HampshireNo date published

Read the source note
“Design Stage 25%, Construction Drawings 40%, Planting Plans 25%, and Tender Management 10%”

Commercial interest: A practice describing its own model. The only stage-weighting we could find anywhere.

Why we did not average these figures

The endpoints differ by two and a half times on the same build. An average would invent a number none of the sources supports. The only point of agreement is the direction: the percentage falls as the build cost rises.

02 · Build costs

What does the build itself cost?

Far more than the design. AI cannot lay a slab, but the labour line is where self-building can change the total most dramatically.

50–60%

Published labour share

2022

Age of that source

Full evidence ledgerOpen all 9 sourced build-cost records

Patio, laid

£120–£475 per m²

Excludes VAT — stated in the table heading

Checkatrade (flagstone patio)July 2025

Read the source note
“£120 - £475 per m²”

Commercial interest: Paid trade directory.

Decking

£80–£300 per m²

VAT basis not stated

MyBuilderUpdated May 2026

Read the source note
“Decking cost per square metre typically ranges from £80-£300.”

Commercial interest: Lead-generation directory.

Turf, supplied and laid

£13–£20 per m²

Supply and lay. Materials alone quoted separately at £3.50–£7

MyJobQuoteJuly 2026

Read the source note
“Laying Turf: £13–£20 per m²”

Commercial interest: Lead-generation directory.

Retaining wall, stone

£395+ per m²

Excludes VAT — stated in the table heading

CheckatradeMarch 2025

Read the source note
“£395+”

Commercial interest: Paid trade directory.

Splitting a garden over two levels

£11,000–£13,000

VAT basis not stated

MyJobQuoteJune 2026

Read the source note
“If you want your garden to be spread out across two levels, you'll likely pay between £11,000 to £13,000 for digging, filling, and building a retaining wall.”

Commercial interest: Lead-generation directory.

Timber pergola, large

£2,200–£4,100

VAT basis not stated

MyJobQuoteJune 2026

Read the source note
“£2,200 - £4,100”

Commercial interest: Lead-generation directory.

Turnkey garden room

£11,750 average

Supply and install

CheckatradeJune 2026

Read the source note
“A turnkey garden office pod with double-glazing, insulation and felt roofing can cost on average £11,750”

Commercial interest: Paid trade directory.

Labour as a share of the whole project

50%–60%

Ratio only

Older figure

Real HomesJuly 2022

Read the source note
“Typically, labour costs amount to 50 to 60 per cent of a project's costs, so, with a £10,000 budget – typical for urban gardens – that leaves £4,000 for clearance work and skip hire, design fees (around £1,500)”

Commercial interest: Consumer magazine with affiliate revenue. This is the single most important number on the page for the self-build argument, and it is four years old. Treat it as an order of magnitude, not a figure.

Landscaper day rate

£110–£360 depending who you ask

Labour only, VAT added on top

MyJobQuote, MyBuilder and Checkatrade2025–2026

Read the source note
“Most professional landscapers who are VAT-registered will add VAT on top of their quoted price.”

Commercial interest: All three are lead-generation directories. See the disagreement note below.

VAT is inconsistent

Only two sources say whether VAT is included. Comparing figures across sources is therefore unsafe.

Directories copy each other

Four retaining-wall prices match across two sites to within a few pounds. Treat them as one source, not two.

The labour ratio is old

The 50–60% labour-share figure is from 2022. It is useful only as an order of magnitude.

Day rates do not converge

Published landscaper rates run from £110 to £360 a day. There is no defensible single figure.

Five saving channels

Where could AI actually change the money?

Replacing a designer is the easiest saving to describe. It is not necessarily the largest. AI can affect the total through five separate channels, including one that runs in the wrong direction.

Efficiency is the wrong frame.

“How much cheaper was it?” assumes the project happens either way. Often the real alternative is no project at all. That is not a percentage saving — and it is why we are testing the idea on a real build. We have already run that experiment once.

  1. Channel 01

    Doing the project at all

    The largest, and not a saving in any accounting sense

    The counterfactual is not a cheaper garden. It is no garden. If the prospect of learning twenty unfamiliar trades from scratch is what stops you starting, then the first thing AI changes is whether the project happens — and a project that happens is not a percentage saving on one that did not.

    What evidence exists?

    Unmeasurable and self-reported: nobody can audit a decision you did not take. We know it is real because it already happened to us once — Collab365 Spaces was built this way and would not exist on our budget otherwise. That is an anecdote, not evidence, which is exactly why we are running it again somewhere anybody can check.

  2. Channel 02

    Labour you no longer buy

    Potentially many times the design fee

    Every metre of wall, run of cable trench or square metre of paving you lay yourself is labour you do not pay for. This is where the real money is, and it is available only if you are willing and able to do the work.

    What evidence exists?

    The rates are well sourced — landscapers are quoted at £110 to £360 a day depending which directory you read. What is not evidenced is whether an AI-taught amateur produces work that lasts.

  3. Channel 03

    Design work you do yourself

    Part of 8 to 20 percent of the build cost

    The concept stage, the layout, the planting scheme. This is the channel everyone talks about because it is the one with a published price attached.

    What evidence exists?

    The only stage-weighting published anywhere puts construction drawings at 40 percent of a designer's fee — the biggest slice, and the part consumer AI is furthest from producing.

  4. Channel 04

    Buying and specifying better

    Unknown, but it is the channel with the fewest downsides

    Knowing what to ask an electrician before they quote. Knowing what a fair quantity looks like. Being able to compare two quotes that are not written to be comparable. This does not save you the trade's fee, it saves you from paying for the wrong thing.

    What evidence exists?

    Unmeasured. We could find no study on whether better-informed clients get better prices in domestic construction.

  5. Channel 05

    Rework you cause

    Negative, and the reason the case against matters

    The channel that runs the other way. A wall built in the wrong place, a fall running towards the house, a cable in the wrong trench. Confidence that is not matched by competence is expensive.

    What evidence exists?

    Errors already cost UK construction far more than anyone budgets for. There is no figure specific to AI-designed domestic work, because nobody has measured that either.

Generic information versus your siteWhy can’t you just watch YouTube instead?

A video can explain a problem. It cannot answer about your cover depth, aspect, soil, access or local quote. Translating somebody else’s garden into yours is the part an inexperienced person cannot safely do alone.

What a video gives you

What you need on site

Someone else's manhole cover, in someone else's patio

Whether yours can be raised or covered, and who has to sign that off

A planting list for a shady border

A list for a north-east facing bed on clay that sits wet until March

A general order of works

Whether your side access is wide enough before the wall goes up

A quoted price from 2021, somewhere else

What is reasonable for this, here, this month

A finished result, edited

What to ask the electrician before they start, so you get the right thing

Confidence without competence is how you rebuild the same wall twice. Structure, drainage, electrics and anything load-bearing still need somebody insured to check the answer.

Risks and accountability

What could make those savings disappear?

The strongest evidence does not say AI is always wrong. It says the failures are hard to predict, people misjudge whether AI helped them, and the cost of one confident mistake can overwhelm years of subscription fees.

  1. 01

    Strongest, because it is an admission against the vendor's own interest

    OpenAI tells you not to rely on it

    A £20-a-month subscription comes with no accuracy guarantee and no recourse. A designer who is a member of the Society of Garden and Landscape Designers is obliged to carry insurance against exactly the loss a wrong answer causes.

    Read the evidence
    “You should not rely on Output from our Services as a sole source of truth or factual information, or as a substitute for professional advice.”

    OpenAI Terms of Use, applicable to UK users · Effective 1 January 2026

  2. 02

    Strong on the reliability of self-reported savings. Not about gardens

    People believe AI sped them up when it measurably slowed them down

    The measured result was 19% slower. This is software development, not landscaping, and METR explicitly say it should not be generalised to other domains. We include it for one narrow reason: it is direct evidence that people are poor judges of whether AI saved them anything. Which means every homeowner testimonial about AI saving money, including ours, is weak evidence.

    Read the evidence
    “developers expected AI to speed them up by 24%, and even after experiencing the slowdown, they still believed AI had sped them up by 20%.”

    METR — a randomised trial with experienced software developers · 10 July 2025

  3. 03

    Strong, UK, large sample

    On UK official information, the failure mode is rare but severe

    Not “mostly wrong”. Mostly right, with occasional badly wrong. That is the failure mode most likely to survive your sanity check and reach the build, which is exactly why permitted development limits and drainage rules are the worst possible things to take from a chat window.

    Read the evidence
    “All tested models showed an extremely high variance and a 'long tail', demonstrating unreliability”

    Open Data Institute, 22,000+ queries against GOV.UK sources · 5 February 2026

  4. 04

    Direct to the topic. Non-UK, and multiple choice

    On construction estimating specifically, no model reached 80%

    That is the ceiling, not the floor. Picking from options is easier than generating a price from nothing, which is what you are asking for when you type “how much will this patio cost”.

    Read the evidence
    “all models achieve accuracy below 80%, even though CEQuest is a relatively straightforward multi-choice dataset”

    CEQuest benchmark, arXiv · 22 August 2025

  5. 05

    Important, because this study gets cited without the caveat

    The famous 99.84% accuracy result was given the prices first

    The model was doing arithmetic on numbers it had been handed. It was not sourcing UK prices. You do not have a rate book, so this result does not transfer to you.

    Read the evidence
    “Prior knowledge regarding production rates, labor hourly rates, equipment rates, and material rates was used as input.”

    Ghasemi & Dai, Smart Construction · 4 September 2024

  6. 06

    UK, but industry-wide rather than domestic

    Errors already cost UK construction more than anyone budgets for

    This is whole-industry, dominated by major projects, and there is no domestic-garden equivalent. But the arithmetic is worth doing: one rework event at 10% of a £15,000 garden is £1,500, which is six years of an AI subscription.

    Read the evidence
    “Key international studies suggest that the direct cost of avoidable error is in the order of 5% of project value. Our research has revealed that the true figure is closer to 21% or £21 billion per annum.”

    Get It Right Initiative · Accessed July 2026

The accountability gap

What does a designer give you that AI cannot?

Not taste. Insurance, professional accountability and a route to recover a loss when advice is wrong.

A professional designer

SGLD members must carry professional indemnity insurance and remain personally accountable for their practice.

Read the insurance sources

An AI service

OpenAI’s terms say the service is provided “AS IS” and that output should not be relied on as a substitute for professional advice. A chatbot carries no professional indemnity for your build.

OpenAI Terms of Use, January 2026

The running account

The number does not exist. We are going to be the number.

Nobody has published a real, itemised and dated account of a UK garden designed and built with AI. We will publish ours as the money is actually spent.

Known now

8–20%

The published design-fee range

Not known

Net AI saving

No project result exists yet

What we will publish

The ledger

Quotes, spend, mistakes and rework

Every quote, every mistake, every time the AI was confidently wrong and what correcting it cost. Not a forecast or a case study written afterwards by someone with something to sell — a running account from two people whose own money is in the ground.

If we spend more than a designer would have charged, we will publish that too. It would be a more useful result than a flattering estimate.

What the account will record

  • Every real quote and purchase as it happens
  • Design work, self-build labour and paid labour kept separate
  • Mistakes and rework included, not written out afterwards
  • What remains unmeasured stated plainly
See what has gone wrong so far Start free

Researched and published 25 July 2026; page structure updated 26 July 2026. Every figure carries its source, date and commercial interest. Where sources disagree, the disagreement remains visible. Where no evidence exists, the page says so.

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