The Complete Guide to House Extensions in 2026
Everything you need to know before extending your home — from planning and costs to choosing the right builder. Written by our team from 39 years of experience.
Eight Chapters of Expert Guidance
Planning Permission vs Permitted Development
When you need planning permission and when you can build under permitted development rights.
Cost Guide by Extension Type
Realistic 2026 pricing for single-storey, double-storey, side-return and wrap-around extensions.
Timeline Expectations
How long each phase takes — from initial design to final handover.
How to Choose a Builder
The essential checklist: accreditations, insurance, references and red flags to avoid.
Common Mistakes to Avoid
The pitfalls that cost homeowners time and money — and how to sidestep them.
VAT, Building Regs & Party Walls
The legal and regulatory requirements you need to understand before breaking ground.
Maximising Return on Investment
Which extensions add the most value — and which don't deliver what you'd expect.
Living Through a Build
Practical advice for staying sane while your home is a building site.
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