Building a house extension is one of the best ways to add more space, comfort, and value to your home. However, successful extensions require careful planning and consideration before work begins.
At Nrmltd, we guide homeowners across London and Essex through the process, ensuring a smooth, stress-free experience.
Here are 8 essential things you must consider before starting your house extension project.
1. Understand Your Goals
Start by clearly defining what you want to achieve.
Do you need extra bedrooms?
A larger kitchen or open-plan living space?
A home office or garden room?
Knowing your extension goals will shape every design and budgeting decision moving forward.
2. Check Planning Permission and Building Regulations
Not all house extensions need planning permission, but some do — especially for larger or unusual builds.
You must also comply with Building Regulations covering structural integrity, fire safety, insulation, and accessibility.
Nrmltd can handle all planning and regulatory approvals on your behalf, ensuring a hassle-free experience.
3. Set a Realistic Budget
It’s vital to set a realistic budget early, including a contingency (usually 10–15%) for unexpected costs.
Budget for:
Design and architectural fees
Planning and approval costs
Build materials and labour
Fixtures, fittings, and finishes
We offer transparent quotations with no hidden surprises.
4. Choose the Right Design
A great extension should complement your existing home — both structurally and aesthetically.
You’ll need to consider:
Roof styles
Window placements
Exterior finishes
Internal flow and functionality
At Nrmltd, our architects create designs that blend perfectly with your home while maximizing natural light and space.
5. Think About the Impact on Your Neighbours
Extensions often affect neighbouring properties — especially in terraced or semi-detached homes.
It’s good practice (and sometimes legally required under the Party Wall Act) to inform your neighbours early.
Building positive communication helps avoid disputes and delays later.
6. Maximise Natural Light
Well-designed extensions capture as much natural light as possible, making new spaces feel bigger and more welcoming.
Options include:
Skylights
Bi-fold doors
Floor-to-ceiling windows
Nrmltd specialises in light-optimised designs that enhance your home’s beauty and comfort.
7. Plan for Heating, Plumbing, and Electrical Work
Don’t forget that extensions often involve extending your home’s services.
Consider:
Additional radiators or underfloor heating
Plumbing for new kitchens, bathrooms, or utility rooms
Extra sockets, lighting, and possibly upgraded fuse boards
We coordinate all mechanical and electrical services as part of your build.
8. Choose an Experienced Builder
Finally, choosing the right construction company is crucial for a successful extension.
Look for:
Proven experience with similar projects
Strong client testimonials
Full insurance and professional guarantees
Transparent communication from start to finish
At Nrmltd, we are proud to offer expert craftsmanship, reliable project management, and a commitment to delivering your dream extension — on time and on budget.
Final Thoughts
Building a house extension is a big investment — but with careful planning and the right team, it can transform your home and lifestyle.
Nrmltd is here to support you at every stage, from initial ideas to final completion.
Ready to extend your home?
Contact Nrmltd today for a free site survey and personalized advice.
Quick FAQs
Q: How long does a house extension take?
Typically, a straightforward extension takes 10 to 16 weeks, depending on complexity.
Q: Will I need to move out during the extension build?
In most cases, you can stay in your home while the work is carried out, with minimal disruption.
Q: How much does a house extension cost?
Costs vary, but you can expect around £1,800 to £2,500 per square metre for a quality extension in London and Essex.
