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Professional Negligence

Which Grand Designs projects failed to stay on budget?

Been Let Down’s Professional Negligence team examine Grand Designs most well-known builds that didn’t go according to plan and offers advice on how to best plan for a construction project.

Hard hat on table

Grand Design projects rarely go to plan

Grand Designs has been a mainstay of British television for over 20 years, and its popularity endures as every month across the UK there are almost 50,000 Google searches for “Grand Designs” and the projects it has featured.

The projects are ambitious, striking, and rarely go according to plan.

Take for instance the October 2019 episode set in North Devon, featuring an ambitious lighthouse build which exceeded its budget by over £1m. With that project recently being put up for sale, we decided to dig deep into Grand Designs builds to find out which projects failed to go to plan – factoring in initial budgets versus the final total cost, and any unforeseen issues in construction.

Shockingly, the ambitious and oftentimes visionary homeowners that document their home projects on Grand Designs rarely complete their dream home within the expected budget – across more than 200 episodes, we discovered that more than three in every four (77%) came in over budget.

Grand Designs Budget Breakers

Many of the projects which ended up massively exceeding the initial cost estimate experienced issues or delays during the construction process, while sometimes the additional spend was down to things such as incorrect structural surveys, delays in getting planning permissions or DIY project management.
However, for the majority it was simply down to a miscalculation of the total costs at planning stage.

The most over-budget builds

  1. “Low Impact House”, Season 17 (+5300% over budget)
    The project began with Simon and Jasmine Dale setting out to hand-build an ecological home with just £500 in the bank. The couple set out to make a home that would allow them to be self-sufficient within five years – complex planning requirements due to the nature of the project meant the house took six years to build – for a final total of £27,000, a massive 5,300% over the initial starting sum. After the episode aired, the home sadly burned to the ground in a fire on New Year’s Day, with the couple setting out to rebuild.
  2. The 16th Century Farmhouse, Season 5 (+328% over budget)
    Following closely in second place is the 16th Century Farmhouse featured on Season 5, which came in more than 300% over its original budget owing to structural problems that weren’t identified in the initial structural survey. The final build ended up costing around £300,000, way more than the £70,000 originally forecast.
  3. Huxham, Devon, Season 22 (+199% over budget)
    The most expensive project amongst the top 5 most over-budget – Season 22’s visit to Huxham – came in almost 200% over budget with a final total of £2.5m. The build was complicated by structural issues owing to a unique design, as well as delays caused by Brexit and Covid-19.
  4. The Bath Kit House, Season 8 (+ 181% over budget)
    This ambitious build, budgeted at £675,000 to begin with, ended up costing over £1.9m – a huge 181% over the initial sum. The owners faced a considerable number of issues during the build, including groundworks problems and the neighbour’s wall collapsing onto the site.
  5. The Seaside House, Season 15 (+ 158% over budget)
    Due to another big budget miscalculation at planning stage, this impressive modern house ended up costing Bram Vis and wife Lisa a grand total of around £2.2m, way over their initial budget of £850,000.

The unfinished projects

In some cases, the issues faced led to builds being unfinished for months or years after the episode initially aired.

  1. The Lighthouse, Season 20
    Commonly seen as the “saddest” project to be shown on Grand Designs, Season 20’s Lighthouse build remained unfinished when the episode aired in 2019 – with the married couple separating due to the debt incurred on the project. By the time the episode aired the build had gone over budget by 66%, to a cost of around £3m (a £1.2 million increase on the initial £1.8 million budget). Amongst the unfinished projects analysed, it was the most expensive one.
  2. The Cob Castle, Season 13
    “The Cob Castle”, which appeared on season 13, went over budget by 114%, with a total cost of £750,000 compared to the starting budget of £350,000. The owners faced days of torrential rain which ended up delaying the construction process.
  3. The Eco-Barge, Season 7
    With multiple issues including arguments with the builders, evictions and problems getting permanent mooring, the Eco-Barge ended up exceeding the initial £50,000 budget by 60%, ending up at about £80,000 when the episode aired in 2007, remaining unfinished.

Grand Designs “disasters”

Episode Title and Season Build Location Initial budget Final cost % difference between budget and final cost Issues during build
“Low-Impact House”, Season 17 Pembrokeshire £500 £27,000 5300.00% Electrical fire
“The 16th Century Farmhouse”, Season 5 Gloucester £70,000 £300,000 328.57% Structural issues due to first structural survey not being done correctly
“Huxham”, Season 22 South Devon £835,000 £2,500,000 199.40% Structural complications due to unique design
Delays and complications caused by the Covid pandemic and Brexit
“The Bath Kit House”, Season 8 Bathwick Hill, Bath, Somerset £675,000 £1,900,000 181.48% Groundworks issues
Underground stream
Neighbour’s walls collapsed
“The Seaside House”, Season 16 Solent, Isle of Wight £850,000 £2,200,000 158.82% Huge budget miscalculation at initial project stage
“South Hertfordshire: Roman House”, Season 18 Hertfordshire £600,000 £1,500,000 150.00% Planning delays for six years
“The Derelict Mill Cottage”, Season 11 Newcastle, Northumberland £250,000 £600,000 140.00% DIY project management
Steel frame budget miscalculation
“The Cob Castle”, Season 13 East Devon £350,000 £750,000 114.29% Torrential rain delayed construction
“The Perfectionist’s Bungalow”, Season 16 West Sussex £750,000 £1,500,000 100.00% Issues and miscalculations with the glazing system
“The Urban Shed”, Season 14 South East London £300,000 £600,000 100.00% Difficulty getting planning permission
DIY project management
Foundations had to be built deeper than planned
“North Devon”, Season 20 Devon £1,800,000 £3,000,000 66.67% Building site was too dangerous to construct on
“The Eco-Barge”, Season 7 Medway £50,000 £80,000 60.00% Arguments with builders’ team over materials
Multiple evictions
Issues getting permanent mooring

Most cost-effective Grand Designs builds

Some projects featured on the show have managed to come in under budget – though just 4% of all the builds featured have managed to do this.

The most cost-effective Grand Design was the Stealth House, featured in Season 10. The final total came in £50,000 shy of the initial £650,000 budget – 7.69% cheaper than envisioned.

Most cost-effective builds

Episode Title and Season Build Location Initial Budget Final Cost % difference between budget and final cost Saving from initial budget planning
“The Stealth House”, Season 10 Cotswolds £650,000 £600,000 -7.69% -£50,000
“The Scandinavian House”, Season 10 Horsham £880,000 £840,000 -4.55% -£40,000
“The Cave House”, Season 17 Worcestershire £100,000 £96,000 -4.00% -£4,000

Our advice for getting your construction project right

Whether you’re looking to take on a Grand Designs-scale project or a more conventional home renovation, getting the initial planning right could save you money down the line – as some of the most over-budget Grand Designs can evidence.

Rob Godfrey, Head of Professional Negligence at Been Let Down, gives his advice on the top three aspects to look out for before kickstarting a renovation or construction project.

  1. The budget
    Getting the initial budget right is a vital first step to any construction project. If the initial cost estimate is not accurate, this could result in delays in completion, additional costs or, in the worst-case scenario, with the initial project completely ruined.
    Architects can sometimes fail to get budgeting right, either by overestimating costs or underestimating them. It’s important for anyone undertaking a construction project or renovation to be aware of this, as it could totally skew decision-making on the works and how the project progresses.
  2. The initial survey
    It is essential to understand the structural background before committing to a renovation project. Any project will fail if it is based on an incorrect survey which missed important defects or weaknesses of the structure itself, as unexpected issues may arise during the build.
    If surveyors miss particular requirements affecting the integrity of the development, this can not only delay the construction or renovation project, but it will also come with severe cost consequences.
  3. Groundworks
    Groundworks occur at the preliminary stage of developments to ensure good foundations and conditions for the project, both geotechnically and environmentally. Development of brownfield sites are among one of the more vulnerable projects – if groundworks are inadequately carried out, this can result in disastrous consequences for the later works. Careful planning before initial work can also save money, hassle, and potentially more severe problems down the line.

We’re here to help with your property negligence claim

While not all renovation issues occur as a result of professional negligence, if you consider that the standard of service you received from a property professional (including architects, engineers, or surveyors) was below what you would have expected, and this has resulted in financial loss, then our solicitors may be able to assist you.

If you or someone you know has been affected by improper planning and development of a property, get in touch with our team of specialist professional negligence solicitors. We are here to listen to you and provide you with the care and advice you need.

Please call us on 0800 234 3234 or contact us and a member of our legal team will call you back.


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