Loft Conversion vs Extension
Make an informed decision about Loft Conversion vs Ground Floor Extension for your North London home.
Loft Conversion
Convert your existing loft space into a habitable room. Most loft conversions in London are dormer or Velux conversions, adding 1-2 rooms within the existing roof structure.
✓ Advantages
- ✓Usually doesn't require planning permission (Permitted Development)
- ✓Faster completion (6-10 weeks typical)
- ✓Less disruptive to daily life
- ✓Doesn't reduce garden space
- ✓Often better views from higher floor
- ✓Typically cheaper than extension
✗ Disadvantages
- ✗Limited by existing roof structure
- ✗Head height restrictions may limit use
- ✗Staircase takes space from floor below
- ✗May not be possible on all properties
- ✗Fire regulation requirements
Best for: Properties with adequate roof height (2.2m+), Homeowners wanting quick results, Those wanting to preserve garden, Budget-conscious projects, Creating extra bedroom/office
Price range: £35,000 - £75,000
Ground Floor Extension
Extend your property's footprint at ground level. Options include rear extensions, side returns, wraparound extensions, or double-storey additions.
✓ Advantages
- ✓More design flexibility
- ✓Can create large open-plan living
- ✓No head height limitations
- ✓Better for kitchen/living expansion
- ✓Can add more square footage
- ✓Greater potential value uplift
✗ Disadvantages
- ✗Often requires planning permission
- ✗More expensive (groundworks, foundations)
- ✗Longer build time (12-20 weeks)
- ✗More disruptive during build
- ✗Reduces garden space
- ✗Neighbour considerations
Best for: Expanding kitchen/dining spaces, Creating open-plan living, Properties with generous gardens, Those wanting dramatic transformation, Long-term family homes
Price range: £50,000 - £150,000
Side-by-Side Comparison
| Feature | Loft Conversion | Ground Floor Extension |
|---|---|---|
| Typical Cost | £35,000 - £75,000 | £50,000 - £150,000 |
| Build Time | 6-10 weeks | 12-20 weeks |
| Planning Permission | Usually not required | Often required |
| Disruption Level | Moderate | High |
| Space Added | 15-30 sqm typical | 20-50 sqm typical |
| Design Flexibility | Limited by roof | Very flexible |
| ROI / Value Added | 10-20% value increase | 15-25% value increase |
| Garden Impact | None | Reduces space |
Our Expert Verdict
For adding a bedroom or office, loft conversions offer better value and less disruption. For transforming your ground floor living space, an extension is worth the investment. Many homeowners do both over time.
Choose Loft Conversion if:
- →You need an extra bedroom or office
- →Budget is a primary concern
- →You want minimal disruption
- →Your garden space is precious
- →You don't need planning complications
Choose Ground Floor Extension if:
- →You want open-plan kitchen/living
- →Your ground floor feels cramped
- →You have a generous garden
- →You're planning a long-term stay
- →Maximum value uplift is the goal
Frequently Asked Questions
Which adds more value to my home?▼
Both add significant value. Loft conversions typically add 10-20% to property value. Extensions can add 15-25%, especially large kitchen-diners in family areas. In Hampstead, extensions often deliver the highest percentage returns.
Can I do both a loft conversion and extension?▼
Yes, many clients do both, either simultaneously or in phases. Doing both together can be cost-effective (shared scaffolding, one planning application). We can project manage combined works.
Do I definitely need planning for an extension?▼
Not always. Permitted Development allows rear extensions up to 3m (attached) or 4m (detached) without planning. However, conservation areas, listed buildings, and large extensions require full planning.
How do I know if my loft is suitable?▼
We offer free loft assessments. Key factors: head height (2.2m minimum from floor joist to ridge), roof structure (trussed roofs need more work), stair positioning, and existing dormers. Most Victorian/Edwardian properties are suitable.
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Need Expert Advice?
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