Published: 12 January 2026
Starting a house extension or home renovation in London and Surrey is an exciting step, but for many homeowners, it can also feel daunting. Building work is a major investment, and if you haven’t been through the process before, it’s not always clear what to expect when working with a builder in London or Surrey.
At Signature Build Properties, we believe that most building problems are preventable with the right preparation, communication, and professional guidance. Based on our experience delivering high-quality house extensions and renovations across London and Surrey, here are some of the most common issues homeowners face during a build, and how you can avoid them.
1. Unclear Quotes and Missing Details
One of the biggest causes of frustration during a house extension or renovation project is discovering that something you assumed was included… isn’t.
This usually happens when quotes are:
- Too brief or vague
- Missing key details about materials or finishes
- Based on incomplete drawings
How to avoid it:
Always ask for a clear, detailed quote that explains exactly what is included and what isn’t. Take time to review specifications for finishes, electrics, plumbing, insulation, and structural work before signing anything.
If you’re unsure what should be included, speak to an experienced builder in London or Surrey early in the process.
2. Budget Overruns and Late Changes
Unexpected costs are a common worry for homeowners planning a house extension in London or Surrey. While genuine surprises can occur, particularly in older London properties, many budget overruns are caused by changes made after construction has already started.
Examples include:
- Altering layouts mid-build
- Upgrading materials once work is underway
- Adding extra features without reviewing costs
How to avoid it:
Finalise your design decisions before work begins wherever possible and allow a sensible contingency. If changes are needed, always ask for a clear cost breakdown before approving additional work.
This is especially important for larger projects such as House Extensions and full property renovations.
3. Poor Communication During the Build
Even a well-planned project can feel stressful if communication isn’t clear. Homeowners working with builders in London and Surrey often feel anxious when they’re unsure what’s happening on site or who to speak to when questions arise.
How to avoid it:
Agree on communication expectations from the start. Regular updates, a single point of contact, and written confirmation of decisions help keep everyone aligned and reduce misunderstandings.
At Signature Build Properties, we prioritise open and honest communication throughout every stage of the build.
4. Delays and Unrealistic Timelines
Building projects rarely run exactly to schedule, particularly in London, where inspections, access restrictions, material lead times, and neighbour-related matters can all affect progress during a home renovation or extension.
Issues often arise when:
- Timelines are overly optimistic
- External factors aren’t explained upfront
- Delays aren’t communicated clearly
How to avoid it:
Be cautious of builders promising unrealistically fast completion. A professional construction company in London or Surrey will set realistic timelines and explain where delays may occur before work begins.
You can learn more about how we approach projects on our About Us page.
5. Neighbour Issues and Party Wall Matters
In built-up areas, building work often affects neighbouring properties. Noise, access, and structural works near boundaries can quickly become points of tension if not handled properly.
How to avoid it:
Speak to neighbours early, follow the correct party wall procedures, and work with professionals experienced in London and Surrey house extensions. Taking a proactive approach can prevent delays and unnecessary disputes.
6. Underestimating the Impact of Living Through a Build
Many homeowners choose to stay in their property during building work or home renovations and underestimate how disruptive it can be, particularly during structural phases.
Common challenges include:
• Noise and dust
• Limited access to kitchens or bathrooms
• Changes to daily routines
How to avoid it:
Discuss working hours, access routes, and safety measures before work begins. Planning ahead makes a significant difference to how manageable the process feels.
7. Choosing the Wrong Builder
Some of the most serious building problems stem from choosing a builder in London or Surrey based solely on price. Extremely low quotes can result in rushed work, poor quality, or ongoing disputes.
How to avoid it:
Look beyond cost. Check experience, references, insurance, and previous projects. A professional builder should be open, transparent, and happy to explain their process.
You may also find our article on Mistakes to Avoid when Hiring a builder useful when comparing contractors.
Final Thoughts
Building work doesn’t have to be stressful. Most problems homeowners face during house extensions and home renovations in London and Surrey come down to unclear expectations, rushed decisions, or poor communication. With careful planning and the right builder, your project can be a positive and rewarding experience.
At Signature Build Properties, we pride ourselves on honest advice, clear communication, and high-quality workmanship across London and Surrey.
Get in touch with our team via our Contact Us page to discuss your project and receive straightforward guidance from experienced professionals.
Free Homeowner’s Build Preparation Checklist
Planning a house extension or renovation can feel overwhelming — especially if it’s your first time. To help you feel more confident and prepared, we’ve created a free, practical checklist that walks you through the key things to consider before and during your build.
✔ Avoid common mistakes
✔ Plan your budget with confidence
✔ Know what to expect at every stage
