When you’re planning a home improvement project whether it’s a new extension, loft conversion, or just knocking through a few walls to open space it’s easy to focus on the exciting stuff. You picture the result: lighter, more space, better flow.
You get caught up in choosing finishes, talking to builders, and scrolling through design ideas. But beneath all that excitement is a layer of legal responsibility that’s all too often overlooked: making sure your project complies with planning permission and building control regulations.
These aren’t just boxes to tick or bureaucratic hurdles to jump over. They’re there for good reason and if you ignore them, you could find yourself facing fines, delays, or even being forced to undo the work. So, what’s the real difference between planning permission and building control? And more importantly, what happens if you don’t follow the rules?
Let’s break it down.
What Happens If You Ignore Planning Permission?
Planning permission is about how your changes affect the wider community. It’s there to ensure your project is appropriate for the area, doesn’t negatively impact neighbours, and fits within broader environmental and development policies. It’s essentially the local authority’s way of managing growth and change in a sustainable and fair way.
If your project does need planning permission and you go ahead without it, you’re not just skipping a formality you’re putting yourself at risk of serious consequences.
You Could Be Hit with an Enforcement Notice
One of the first and most serious consequences of ignoring planning permission is receiving an enforcement notice from your local council. This is not just a warning it’s a formal legal demand requiring you to undo or change the work you’ve done. This can include everything from altering the design to completely removing structures, and you’ll have to do it at your own expense.
These notices carry legal weight. Once issued, you can’t just ignore them or hope the issue goes away. If you fail to comply within the time given which can sometimes be as little as a few weeks the council can take legal action against you. That could lead to hefty fines or, in some cases, prosecution in court. What’s more, the presence of an enforcement notice becomes part of the property’s planning history, making it harder to get approval for any future work.
Even if your project seems minor, like installing a garden office or converting a garage, councils take unauthorised development seriously. And they’re increasingly proactive, with planning enforcement teams using drones, mapping software, and even neighbour tip-offs to monitor changes in residential areas.
Selling Your House Becomes a Headache
Planning permission issues don’t just affect you in the short term they can cast a long shadow over your property’s future, especially when it comes time to sell. During the conveyancing process, your buyer’s solicitor will carry out detailed checks into the planning history of the home. If they discover unauthorised work, it can trigger a whole chain of complications.
First, it can delay the sale while everyone tries to figure out how to deal with the missing permissions. You might be asked to submit a retrospective application at the last minute or offer the buyer a discount. You may even be asked to sort the problem out before contracts are exchanged and that could mean halting the sale while the council reviews your case.
In some situations, the buyer’s mortgage lender might back out entirely. Lenders want to minimise risk, and buying a home with outstanding planning issues is seen as a red flag. This can lead to collapsed chains, lost deposits, and months of wasted time. And even if you find another buyer, the issue won’t go away it’ll continue to show up in searches until it’s resolved.
You Might Struggle to Remortgage or Raise Finance
Even if you’re not selling, planning permission problems can still cause issues if you need to borrow against your property. Many homeowners look to remortgage after completing major work, hoping to release equity and pay off other debts or reinvest in more improvements. But if your lender discovers you’ve carried out unauthorised work, they may refuse the application.
It’s not just about whether the building is safe or looks good. Lenders are cautious by nature, and they’ll only offer loans against properties that are legally compliant. Missing planning permission means your property is technically in breach of regulations, which undermines its market value and resale potential.
If your financial plans depend on refinancing, you could find yourself stuck in your current mortgage — or worse, rejected altogether. And because many lenders now use automated valuation models and planning records during underwriting, it’s getting harder and harder to slip through unnoticed.
Your Home Insurance Could Be Compromised
Another area where people often get caught out is with home insurance. Most policies require you to disclose any building work especially extensions or major alterations and many insurers expect proof that you obtained the right permissions. If you make a claim and the insurer discovers that part of your home was built without planning approval, they could refuse to pay out.
This is especially risky if the damage relates to the unauthorised structure. For example, if your extension floods or catches fire, and you never got planning permission, the insurer may argue the structure was technically not part of the insurable home. You’d be left covering the entire cost yourself.
Even worse, they could cancel your policy for non-disclosure, leaving your whole home uninsured moving forward. This kind of administrative issue can quickly spiral into a financial nightmare all because the right permissions weren’t sorted from the start.
The Costs Can Snowball Quickly
Fixing planning issues after the fact is rarely simple, and it can become much more expensive than if you’d followed the rules in the first place. You may need to hire a planning consultant to assess your chances of getting retrospective approval, pay for new architectural drawings, or even carry out public consultations with neighbours depending on the scale of the work.
Retrospective applications also carry planning fees, and if they’re refused, you could be ordered to remove the development entirely. That’s money and time lost, not to mention the cost of restoring the site to its previous state. If you’ve added plumbing, electrics, insulation, or roofing to the structure, undoing the work is rarely straightforward you’re essentially paying twice for the same project: once to build it, and again to take it down.
If you’ve taken out loans or used savings to complete the work, this can put you under significant financial pressure, especially if your only option is to return the space to its original form.
What Happens If You Ignore Building Control?
While planning permission focuses on how your project affects others, building control is all about how your project affects you and the safety of your home. It ensures that construction work meets national safety, energy, and accessibility standards. This includes everything from the strength of your foundations to your insulation, wiring, ventilation, fire protection, and more.
Even if your project doesn’t require planning permission, you almost always need building control approval.
Unsafe Work Becomes a Real Risk
The biggest danger of ignoring building control is that you could unknowingly compromise the structural safety of your home. Without an expert checking each stage of the build, there’s no guarantee the work is safe — even if it looks fine on the surface.
For example, your loft conversion might not have sufficient support beams. Your electrics might be wired in a way that increases fire risk. Your new bathroom could be improperly ventilated, leading to long-term damp and mould problems. These are not small issues they can lead to serious health and safety risks for you, your family, and anyone else who lives in the property in the future.
A qualified building inspector can spot these problems during construction and help you correct them before they become expensive disasters.
You Won’t Get a Completion Certificate
When the work is complete, your building control officer should issue a completion certificate proof that everything complies with the latest regulations. Without this certificate, you’re left with a project that’s legally unfinished, and that causes problems down the line.
If you ever want to sell or remortgage, you’ll need that certificate. Buyers and lenders both want to know that the building work meets current safety standards, and without documentation, many will walk away.
Even renting out your property can become problematic without proof of compliance — particularly if you’re dealing with local licensing schemes or mortgage terms that require full regulatory sign-off.
Retrospective Approval Can Be a Nightmare
If building control wasn’t involved during construction, you can apply for a regularisation certificate — but this isn’t straightforward. Inspectors will likely need access to areas behind walls, under floors, or above ceilings to assess whether the work meets standards. That might mean tearing up your flooring, removing plasterboard, or even taking out fitted units.
You’ll be paying again just to expose and re-do work — and if the build doesn’t pass inspection, you’ll have to pay again to fix it properly.
You Could Face Legal or Financial Penalties
In more serious cases especially where the work is dangerous or causes harm — the local authority can prosecute. They may issue fines, order remedial work, or in extreme cases, demand demolition of non-compliant structures. You might also be held liable for injury or damage caused by unsafe work, which could result in major compensation claims.
Already Gone Ahead Without Permission? Here’s What You Can Do
If you’ve already carried out work without the proper approvals, don’t panic but don’t ignore it either. The longer you wait, the more complicated it becomes to resolve. The best course of action is to be proactive and transparent.
Apply for Retrospective Planning Permission
If your development requires planning permission, you can submit a retrospective application. This allows the council to assess the work after it’s completed. While this route does give you a second chance, it doesn’t guarantee approval. If the work breaches planning policy, you may still be asked to remove or alter it.
That said, councils are often more sympathetic when homeowners come forward themselves rather than being reported. Demonstrating that you’re willing to follow the correct process can make a big difference.
Apply for a Regularisation Certificate
For building control, your option is a regularisation certificate. This applies to work done after 1985 and gives building control the opportunity to inspect the completed work. They may require some opening, structural calculations, or reports to verify everything meets regulations.
Again, this can be time-consuming and costly but it’s far better than continuing with non-compliant work and hoping for the best.
Final Thoughts: How DMS Architects Help You Get It Right First Time
Planning a home renovation, extension, or conversion should be exciting — not stressful. At DMS Architects, we’re here to make sure your project is not only beautifully designed, but also fully compliant with planning and building control from the very beginning.
We know how easy it is to get caught up in choosing finishes and thinking about the end result. But without the right permissions in place, that dream space can quickly become a costly mistake. We help our clients avoid those risks by managing the process properly from day one — handling applications, preparing accurate drawings, liaising with local authorities, and ensuring your build meets every regulation.
Whether it’s securing planning permission, navigating permitted development rules, or managing building control approvals, we take care of the details so you can focus on the transformation ahead. We’ll advise on what permissions are needed, how best to approach your local council, and what steps to take if you’re correcting unauthorised work.
If you’re unsure about what permissions your project needs — or worried about work that’s already been carried out — we’re here to help you find the best way forward. We’ve worked with homeowners across a wide range of projects, and we understand how to protect your time, your investment, and your peace of mind.
Get in touch with DMS Architects, and let’s make sure your project is safe, legal, and something you’ll be proud of for years to come.
