Home Renovations
Home renovations can completely transform how you live in your home, but they often come with hidden challenges that catch homeowners off-guard. From planning rules and building regulations to unexpected costs and structural surprises, this guide walks you through the issues most people don’t discover until they’re already mid-renovation.
Our aim is simple: to help you plan smarter, avoid stress, and steer clear of the common pitfalls that slow projects down or increase costs unnecessarily.
Thinking about starting a renovation?
We’ll help you understand what approvals you need before you begin.
1. Why unseen challenges happen in home renovations
Most home renovations look straightforward on paper, but once walls are opened, floors are lifted or layouts are changed, unexpected issues tend to appear. These surprises can impact your timelines, approval routes and budget.
Although major extensions get most of the attention, even simple internal renovations can uncover hidden complications. Many homeowners come to us after realising that planning rules, structural requirements and building control approval apply far wider than expected.
Common surprises include:
- discovering structural walls where lightweight partitions were expected
- finding outdated electrics, plumbing or insulation
- renovations unintentionally triggering planning permission
- needing structural calculations for RSJs and openings
- hidden costs such as asbestos removal, drainage adjustments or fire safety upgrades
Most of these challenges are manageable when you know they’re coming. That’s why being prepared — and understanding the approvals route — makes a huge difference.
2. Planning rules vs building regulations
One of the biggest unseen challenges is misunderstanding what needs planning permission and what comes under building regulations. The two systems work in parallel, but they cover completely different things.
Planning permission looks at:
- appearance and impact on neighbours
- overlooking, privacy and light
- wider street scene
- local policies and design guidance
Building regulations look at:
- structural stability
- fire safety (Part B)
- thermal performance (Part L)
- electrics, plumbing and ventilation
- damp resistance, insulation and soundproofing
For more planning-focused guidance, see our main pillar: House Extensions – Complete UK Guide.
You may also find these helpful:
- Planning Permission — UK Homeowner’s Guide
- Building Regulations — Complete Homeowner’s Guide
- Building Control — What It Is & How It Works
3. When renovations require approvals
Most internal refurbishments fall under permitted development, but several renovation types can unexpectedly trigger an application.
Planning permission is often required if you:
- move or enlarge external doors and windows
- alter the roofline
- change the use of a room (e.g., turning a garage into habitable space)
- build or rebuild structural elements
- live in a conservation area or listed building
Building regulations approval is required if you:
- alter structure (e.g., remove load-bearing walls)
- install new electrics, boilers, drainage or plumbing
- convert a loft, garage or basement
- replace windows or external doors
- add insulation or move radiators
Useful related guides:
- Planning Permission for a Garage Conversion
- Building Notice vs Full Plans
- Planning Permission Loft Conversion
4. What home renovations actually involve
Renovations can look deceptively simple from the outside, but they often involve multiple layers of technical work behind the scenes.
Typical renovation tasks include:
- structural alterations (RSJs and new openings)
- rewiring or upgrading old electrics
- moving radiators and plumbing
- insulation and thermal upgrades for Part L
- new drainage or ventilation routes
- window replacements and fire safety upgrades
- layout changes that affect circulation or light
5. Who prepares renovation plans?
No two renovation projects are the same. Depending on the complexity, you may need:
- Architectural designers — for layout changes and planning drawings
- Structural engineers — for calculations on RSJs and load-bearing changes
- Building Control — for inspections and compliance checks
- Specialist contractors — for electrics, plumbing, heating and waterproofing
We help homeowners prepare planning drawings, submit applications and produce full building regulations plans through our dedicated services, including:
6. Costs & timelines
Renovation budgets vary widely, but most unseen challenges relate to cost increases or slower-than-expected progress.
Typical cost influencers include:
- structural changes or needing RSJs
- moving drainage or discovering old pipework
- unexpected rewiring
- insulation not meeting Part L
- fire safety upgrades required by Part B
- Internal wall removal: £1,200–£2,500 (plus RSJ if required)
- New electrics: £2,000–£5,000 depending on scope
- Bathroom renovation: £4,000–£10,000
- Kitchen renovation: £8,000–£25,000
Not sure which approvals your renovation needs?
We’ll review your plans and tell you exactly which route applies.
7. Step-by-step renovation checklist
| 1. | Define what you want to change and why |
| 2. | Check whether planning permission or permitted development applies |
| 3. | Assess building regulations requirements |
| 4. | Arrange a measured survey and design drawings |
| 5. | Secure structural calculations if altering walls |
| 6. | Submit planning or building control applications |
| 7. | Get contractor quotes and timeline agreements |
| 8. | Begin works with regular inspections from Building Control |
8. Pitfalls & gotchas
Other common problems:
- starting work before approvals are confirmed
- discovering structural timbers in poor condition
- skipping drainage checks
- buying materials before design is finalised
- underestimating the cost of finishes
9. Technical considerations
Many renovations trigger technical updates homeowners don’t expect.
These include:
- Fire safety — smoke alarms, escape windows, fire-rated doors
- Thermal performance — meeting Part L insulation minimums
- Ventilation — extractor fans, trickle vents and airflow routes
- Electrics — Part P and certification
- Drainage — moving soil pipes or ensuring correct falls
For deeper guidance, see:
Frequently Asked Questions
Do I need planning permission for home renovations?
Many internal renovations fall under permitted development, but changes to structure, external appearance or roofline may require planning permission. Local council rules can also vary, especially in conservation areas.
Do I need building control approval for internal works?
Yes, if you alter structure, electrics, plumbing, ventilation, drainage or insulation. Building regulations apply far more often than homeowners expect.
What is the biggest hidden cost in home renovations?
Structural work (such as RSJs) and rewiring are two of the most common hidden expenses. Damp issues and drainage surprises also add cost.
Who produces plans for renovations?
Architectural designers produce layout drawings, structural engineers prepare calculations, and Building Control handle inspections and compliance.
How do I avoid delays during renovation?
Ensure you have all approvals upfront, confirm structural requirements early, and avoid changing the design once work has begun.
- Most common unseen issue Structural alterations needing RSJs & calculations
- Regulations likely needed Building Control approval for structure, electrics, drainage & insulation
- When planning is triggered External changes, roof alterations or converting garage/loft
- Typical contingency 10–15% of renovation budget
Next steps & useful guides
If you're planning a renovation, these guides will help you understand the wider process:
- Planning Permission — UK Guide
- Building Regulations — Complete Guide
- Property Extension — Step-by-Step Guide
- Building Control — What to Expect
External authority resources
Ready to move your renovation forward?
Plans Made Easy can prepare compliant plans, manage your submissions and guide you from idea to approval.
Performance Verified ✅
This page meets PME Optimisation Standards — achieving 95+ Desktop and 85+ Mobile PageSpeed benchmarks. Verified on
