Honest comparison
Solid roof upgrade vs full extension
If your existing conservatory feels unusable, you have two options: replace just the roof, or knock the whole thing down and build an extension. Here's the honest comparison of cost, time, planning and resale.
| Factor | Solid roof upgrade | Full extension |
|---|---|---|
| Typical cost | £6,500 – £15,000 | £35,000 – £80,000+ |
| Time on site | 4 – 7 days | 10 – 16 weeks |
| Planning permission | Usually permitted development | Often required |
| Building Regs | Part L + Part A (arranged by you) | Full new-build regs |
| Disruption to home | Minimal, conservatory only | Significant, kitchen/garden access |
| Resale value uplift | Treated as true extension | Higher absolute value, much higher cost |
| Reuses existing structure | Yes, frame and base stay | No, full demolition and rebuild |
| Best for | Existing conservatory needing comfort | Adding new floor space |
Which is better value?
For most homeowners with an existing conservatory, a solid roof upgrade is dramatically better value. You spend roughly a fifth of the cost, finish in days rather than months, avoid most of the disruption, and end up with a fully usable insulated room that valuers treat as proper extension space. A full new-build extension only makes sense if you genuinely need more square footage or the existing conservatory base is structurally beyond saving.
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