Costly home and garden renovation and maintenance mistakes

Meet the experts

Vishal Narbheram is an electrician with 15 years’ experience, and founder of Onward Shift – a mental health platform to help construction businesses and individuals thrive

Rhiannon Odey, content creator at Easy Garden Group

Natalie Marsden, a Plymouth-based painter and decorator, otherwise known as The Lady Painter

High monetary cost mistakes

When it comes to mistakes that impact your wallet, there are a few things that the experts warn against:

Skipping regular electrical inspections

When it comes to electrics, Vish shared that – “one of the biggest money wasters we see is skipping regular electrical inspections. It’s easy to overlook but hidden electrical faults (especially in older properties) can build up quietly and turn into serious and expensive problems down the line.

“Inspections are a bit like a car’s MOT but for your home’s electrics. They should be done roughly every 10 years in a typical house but the older the property, the more often you should get them checked”.

If you’re overdue for an inspection, get a qualified electrician in to carry one out. They’ll assess your system and flag up any issues, categorising them like this:

• C1 – Immediate danger
• C2 – Potential danger
• C3 – Recommended improvement
• FI – Further investigation needed

Vish estimates that costs could be around £150 to £500 for this, depending on the size and condition of the property.

Overwatering in the garden

When it comes to gardening, Rhiannon shared that overwatering can be an expensive mistake – “Overwatering wastes water and can kill plants, costing £20–£100+ to replace. To fix, use a moisture meter and consider a drip irrigation system or smart watering timer. Pairing with a rain sensor creates the perfect low-maintenance setup”.

Poor soil preparation

Rhiannon added that poor soil preparation can also cost to fix – “Planting in unconditioned soil leads to poor growth and wasted investment. To fix, mix compost or organic matter (£30–£60) into soil before planting. Better still, start a compost heap for free to produce nutrient-rich compost”.

Hardscaping errors

Rhiannon also highlighted that hardscaping errors can also prove costly – “DIY patios, raised beds, or paths done incorrectly can crack, sink, or drain poorly, costing £500–£1,000+ to fix. To fix, hire professionals for complex hardscaping to ensure proper foundations and longevity”.

Using cheap paint

Natalie shared that opting for the cheapest paint can end up costing more in the long run – “One common mistake is going for the cheapest paint. Although you may think this helps the bank balance, half the time you end up having to buy more as it’s not the same quality and doesn’t cover well. As they say ‘buy cheap, buy twice’. This isn’t saying to pay for the most expensive just as for recombination on the medium ground”.

Not protecting flooring and furniture when decorating

Natalie added that not protecting flooring and furniture when decorating can also cause costly damage – “I would also definitely emphasise on plastic sheeting and floor coverings for sure. Carpets can be so easily damaged as can furniture. Covering with plastic sheeting, floor covering and plastic back dust sheets can solve this”.

High time ‘cost’ mistakes

As well as mistakes often leading to expensive remedies, the time ‘cost’ of mistakes is also an aspect to consider.

Unqualified electrical work

Vish shared that “letting someone who’s not properly qualified do your electrics might seem like a shortcut but it almost always leads to delays. Unqualified electrical work can take a lot of time to fix and more importantly, it can delay the entire project. Other trades can’t get started until the electrics are sorted, so it ends up having a knock-on effect”.

A qualified electrician will need to go over everything, spot any faults and make it all safe and compliant. This often means taking things apart and starting again, so Vish warns that “not all electricians will take on this kind of job, especially if it involves fixing poor or unsafe work from someone untrained”.

According to Vish, the estimated timeframe to remedy could be “anywhere from a few days to a week but for more complex fixes, it could take much longer”.

Planting in poor soil or wrong plants

Rhiannon shared that “Using unsuitable soil or plants results in slow growth or failure, wasting a season. To fix, test soil (£20 kit) and choose plants suited to your garden. Amend poor soil early with compost.”.

Neglecting weeds in the garden

Rhiannon shared that “Small weeds can become invasive, requiring hours or even days to remove. To fix, weed weekly and apply mulch to reduce regrowth.”.

Improper pruning of plants

Rhiannon shared that “Bad cuts can damage plants, delay flowering, or reduce fruiting for years. To fix, research proper pruning techniques or hire a gardener (£50–£80 for expert help)”.

Not taking enough time to prep before painting

Natalie added that “It’s all preparation and making sure sanding, chalking, filling is all done beforehand and not skipped. This goes for not using an undercoat too – some products do state one coat or self primer but doing your research and looking at reviews would help to pick the right product. For example, for woodwork I always prime bare wood, then undercoat and topcoat woodwork for the best result”.

Forgetting to assess the working area before starting

Natalie shared that “time is something that is so important when it comes to painting and decorating as it’s all part of a plan. I would say always assess the working area – for example, if there is wallpaper that needs stripping this is a first port of call. Filling and chalking can put you back from painting walls and woodwork, so planning will help with timings”.

High legal ‘cost’ mistakes

In some cases, potential legal issues can arise – so due diligence is key in the following areas:

Not getting the right certification for electrical work

Vish highlighted that “not getting the right certification for electrical work is a common and very costly mistake. Things like rewiring or adding new circuits legally require sign-off and without that paperwork, your local council can hold up the project.
If the work hasn’t been certified properly, the council may insist on sending their own inspectors and they don’t come cheap. You’ll also be liable for any work needed to bring things up to standard”.

The safest route is to always hire an accredited electrician from the start – on this, Vish suggests looking for someone registered with NICEIC or NAPIT.

However, if the work’s already been done and you don’t have the paperwork, Vish warns that “you may need to apply for retrospective sign-off from the council and pay for any corrections they require. A good rule of thumb? Hold off on paying the final invoice until you’ve got the proper certification in hand”.

When estimating costs for this, Vish shared that council inspectors typically charge £450+, plus any extra costs for rectification work.

Planting too close to boundaries

Rhiannon highlighted that overhanging branches or invasive roots can cause disputes with neighbours. To fix this, she recommends “checking boundaries and planting large shrubs or trees at least 2m away”.

Protected trees (TPOs)

Pruning or removing trees under a Tree Preservation Order without permission can also lead to fines. To fix this, Rhiannon says to “check local council regulations before starting work”.

Poor drainage and water runoff

Rhiannon also warned that incorrect hardscaping that pushes water onto neighbouring properties can cause legal claims. To fix, you may need to “install proper drainage channels (£500–£2,000)”.

Lime plaster

Natalie highlighted that “one potential legal issue that could come about when painting is not properly considering the type of property and materials used. For example different paint should be used on lime plaster (often listed buildings or buildings of age) compared with normal emulsion for the standard walls”.

High safety ‘cost’ mistakes

Expensive, time-intensive, and legal issues are all unwanted – however, some mistakes could actually lead to safety issues, which could impact you, your family, your pets, your neighbours, or even wildlife.

Tree pruning without expertise

Rhiannon warned that cutting large branches without proper equipment risks serious injury and damage. Instead of attempting this yourself, she recommends hiring a professional arborist (approximately £150–£400 per day).

Misusing power tools

Accidents from trimmers, mowers, or chainsaws are common when used incorrectly. Rhiannon urges anyone using power tools to “wear PPE (goggles £10, gloves £5) and follow safety guides”.

Chemical misuse

According to Rhiannon, overusing pesticides or weedkillers “can harm people, pets, and wildlife”. Using organic alternatives like neem oil or companion planting (£10–£30) are recommended over chemicals.

Common gardening mistakes during summer

As well as these ‘costly’ mistakes, we also delved into some of the most common gardening mistakes that homeowners might make during the summer months.

Overwatering during heatwaves

Rhiannon shares that many gardeners water too frequently in summer, drowning roots, encouraging fungal issues, and wasting water. To fix, she suggests to “water deeply but less often, ideally early morning or evening. Use a moisture meter (£10–£15) or install a drip irrigation system (£50–£200) with a timer. Pairing this with a rain sensor creates a stress-free, efficient watering setup”.

Cutting the lawn too short

According to Rhiannon, cutting grass too close during hot weather weakens roots, causes bare patches, and encourages weeds.  To fix, she suggests to “keep your lawn at around 5–7 cm during summer. Overseed patchy areas (£10–£20) and apply summer lawn feed (£15) to boost recovery”.

Planting at the wrong time of day

Planting or transplanting in midday heat stresses plants, causing shock or wilting. Rhiannon recommends planting “early in the morning or in the evening when temperatures are cooler. Use shade cloth (£10–£20) to protect young or sensitive plants”.

Skipping mulch

Rhiannon also stresses that, without mulch, soil dries out faster and weeds take over. To fix this issue, she suggests applying a “5–8 cm layer of organic mulch like bark, compost, or straw (£5–£8 per bag) to lock in moisture and suppress weeds”.

Ignoring shade needs

Finally, Rhiannon shares that planting sun-sensitive plants in full sun leads to leaf scorch and stunted growth. To fix, “group plants by light requirements and move containers to shaded spots during heatwaves”.

Tips to avoid these pitfalls and mistakes

In a bid to help homeowners avoid some of these issues in the first place, the experts shared some expert tips and advice:

Electrical-specific advice

Vish shared 7 of his tips on how homeowners can avoid making some of these electrical mistakes already outlined in the first place:

• Hire the right people – Always use qualified electricians who are registered with NICEIC or NAPIT.
• Ask smart questions – Make sure you understand what’s being done, how long it will take and whether it’ll meet current regulations.
• Get a few quotes – Don’t just go with the cheapest. If a price seems too good to be true, it probably is.
• Check their credentials – Don’t be scared to ask for proof of qualifications and insurance before they start.
• Stay on top of inspections – Book regular electrical checks (rule of thumb is every 10 years for homeowners, every 5 years for landlords).
• Know the basics – You don’t need to be an electrician but it helps to know where your fuse board is and what to do in case of an emergency.
• Know your limits – DIY has its place but electrics are one of those jobs that are best left to the professionals. It’s safer, smarter and often cheaper in the long run.

Gardening-specific advice

Rhiannon also shared 5 of her tips on how homeowners can avoid costly gardening mistakes:

• Plan ahead– Understand plant needs, sunlight, and soil before planting.
• Test soil – A £20 soil test kit can prevent nutrient issues.
• Do regular maintenance – Small, frequent tasks prevent larger problems.
• Ask for advice – Garden centres and local experts are invaluable.
• Leave certain tasks to professionals – For example, drip irrigation and micro-irrigation are simple DIY projects, but larger systems (e.g., pop-up sprinklers) often require a professional landscaper for proper setup, efficiency, and coverage. Similarly, hardscaping projects (such as patios, decking, and drainage) benefit from expert workmanship to avoid costly future repairs. Also, tree work – such as large-scale pruning or tree removal – is dangerous and needs specialist tools and insurance.

For more information on which tasks homeowners should always consult a professional, rather than attempting to DIY, visit our recent blog on tradespeople’s tricks of the trade.

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*Disclaimer – This blog has been created as general information and should not be taken as advice. Make sure you have the correct level of insurance for your requirements and always review policy documentation. Information is factually accurate at the time of publishing but may have become out of date.