HMO Refurbishment: What You Need to Spend and What You Can Recoup
The gap between buying an HMO-ready property and buying a property to convert to HMO use is significant — both in terms of cost and return. Understanding what a proper HMO refurbishment involves, what it costs in London in 2026, and what level of finish is commercially optimal is essential before any purchase decision is made.
Categories of HMO Refurbishment
Category A: Cosmetic Refresh (Existing HMO)
A property already in lawful HMO use that needs modernisation — new carpets, decoration, kitchen update, bathroom refresh. Cost range: £15,000-£35,000 for a 5-bed.
Category B: Full Refurbishment (Existing HMO)
Complete internal strip and rebuild while maintaining HMO layout. New kitchens, bathrooms, electrical rewire, plumbing update, insulation, decoration. Cost range: £45,000-£80,000 for a 5-bed.
Category C: Conversion (House to HMO)
Converting a standard house to HMO use — potentially adding rooms, adding en-suites, reconfiguring to maximise room count while meeting minimum sizes. Cost range: £60,000-£120,000 depending on scale of conversion.
Legal Minimum Requirements
Before any commercial considerations, you must meet the legal minimum standards that apply to all HMOs. These are non-negotiable and will be inspected by the local authority:
- Fire safety — minimum 30-minute fire doors to all habitable rooms and escape routes, interlinked Grade D1 smoke alarms on all floors, heat detector in kitchen, emergency lighting on escape routes (for larger HMOs)
- Room sizes — single adult minimum 6.51 sqm, two adults 10.22 sqm
- Kitchen facilities — adequate for the number of occupants (typically 1 full kitchen per 5 occupants; larger HMOs need additional facilities)
- Bathroom provision — typically 1 bathroom per 4-5 occupants (varies by borough licence conditions)
- Electrical installation — EICR required, typically requires rewire on older properties
- Gas safety — annual certificate, all appliances and pipework in safe condition
Cost Breakdown: 5-Bed London HMO Refurbishment 2026
| Item | Category B (Full Refurb) | Category C (Conversion) |
|---|---|---|
| Electrical rewire | £8,000-£14,000 | £10,000-£16,000 |
| Plumbing update | £5,000-£9,000 | £8,000-£15,000 |
| Fire safety (doors, alarms) | £6,000-£12,000 | £8,000-£14,000 |
| Kitchen(s) | £8,000-£15,000 | £10,000-£20,000 |
| Bathrooms (2-3) | £12,000-£22,000 | £15,000-£30,000 |
| Flooring throughout | £6,000-£10,000 | £6,000-£10,000 |
| Decoration | £5,000-£8,000 | £5,000-£8,000 |
| Structural works | — | £15,000-£40,000 |
| Total range | £50,000-£90,000 | £77,000-£153,000 |
What Adds Value
Not all spend delivers equal return. Focus on these areas for commercial impact:
- En-suite bathrooms — rooms with en-suites command a £100-£200/month premium over shared bathrooms; the payback period on a well-executed en-suite is typically 18-24 months
- Double rooms over singles — where room dimensions allow, doubling rooms to take couples or two sharers at a higher rate
- Fast broadband — a genuine basic requirement; poor connectivity is a void risk
- Good quality kitchens — attracts young professionals who are increasingly discerning
- Adequate storage — often overlooked but consistently mentioned in tenant reviews
Common Refurbishment Mistakes
- Underspecifying fire safety to save money — enforcement action is expensive
- Over-specifying finishes for the rental market — luxury spec rarely commands proportional rent increases
- Ignoring room sizes — converting a room that does not meet minimum size requirements means licensing problems
- No contingency in the budget — always budget 20% above your builder's quote
- Starting work before checking Article 4 and licensing requirements
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