The Key Difference
Light refurbishment and heavy refurbishment are distinct lending products, not different points on a scale. The classification of your project determines everything: the funding basis, how much you can borrow, when funds are released, what documentation you need, and the rate you pay.
The core distinction is structural. Light refurbishment finance funds cosmetic improvement work against the property's current value. Heavy refurbishment finance funds structural and conversion work partly against the property's future value, the GDV, and releases funds in staged tranches as works progress, overseen by a monitoring surveyor.
The one-line test
If your works require a structural engineer, planning permission, or building regulations approval: it is heavy refurbishment. If none of those apply, it is almost certainly light.
| Light Refurbishment | Heavy Refurbishment | |
|---|---|---|
| Works type | Cosmetic, non-structural | Structural, change of use, conversion |
| Planning permission | Not required | Often required |
| Funding basis | Current "as is" value | Current value + GDV uplift |
| Fund release | Single advance (minimal staging) | Staged tranches with monitoring surveyor sign-off |
| Rate (typical) | 0.55–0.75%/month | 0.65–1.0%/month |
| Maximum LTV | Up to 75% of current value | Up to 70–75% of GDV |
| Typical term | 3–12 months | 6–24 months |
| Time to drawdown | 2–3 weeks | 3–5 weeks |
What Counts as Light vs Heavy?
These categories are more precisely defined than most borrowers expect. Misclassification (applying to a light refurbishment lender for a heavy project) is one of the most common causes of stalled applications.
Light refurbishment: what's included
Light covers improvement work that does not alter the building's structure and does not require planning permission or building regulations approval:
- New kitchen fitting: no structural changes to the room
- New bathroom fitting: no structural changes
- New flooring throughout (all materials)
- Full internal redecoration
- New windows and doors on a like-for-like basis
- Re-wiring within the existing structure
- Re-plumbing within the existing structure
- Central heating replacement or upgrade
- External decoration or render: no structural work
Heavy refurbishment: what's included
Any one of the following triggers a heavy classification:
- Any extension: rear, side, loft, or wraparound
- Loft conversion (even under permitted development)
- Basement dig-out or basement conversion
- Change of use: office to residential, commercial to residential
- HMO conversion: adding bedrooms, shared bathrooms, fire safety works
- Removing or adding load-bearing walls
- Underpinning or structural repairs to foundations
- Any works requiring a structural engineer's sign-off
- Anything requiring building regulations approval
The grey area: open-plan conversions
Removing a wall to create open-plan living is one of the most common sources of misclassification. If the wall is load-bearing (which requires a structural engineer to confirm), the project is heavy refurbishment. Do not assume it is light without professional confirmation.
5 Project Examples: Light or Heavy?
The following real-world examples illustrate how the classification works in practice. In each case the answer is determined by whether structural works are present and whether building regulations or planning permission is required.
- 01
Example 1: Victorian terrace full renovation (LIGHT)
A 3-bed Victorian terrace needs a new kitchen, new bathrooms, full rewire, new plumbing, and complete redecoration. No walls are being moved; the layout is unchanged. No planning permission or building regulations required. Classification: light. The lender advances against current value in a single drawdown. Typical rate: 0.60–0.70%/month.
- 02
Example 2: Rear extension on a semi-detached (HEAVY)
A 3-bed semi-detached requires a rear kitchen extension of 6m under permitted development, plus internal refurbishment. Even though planning permission is not required (permitted development), building regulations approval is needed and a structural engineer must sign off steelwork. Classification: heavy. Funded against current value + GDV with staged tranches.
- 03
Example 3: Loft conversion with dormer (HEAVY)
A terraced house is to have a loft conversion with a dormer window to create an additional bedroom with ensuite. Building regulations approval is required. A structural engineer must certify the floor joists and steelwork. Classification: heavy, regardless of whether planning permission is needed.
- 04
Example 4: Office-to-residential conversion (HEAVY)
A vacant first-floor office above a retail unit is being converted to two flats under prior approval (permitted development, not full planning). Structural and fire safety works are required to create separate dwellings. Classification: heavy. GDV is based on the value of the two completed residential units.
- 05
Example 5: Buy-to-let refresh between tenants (LIGHT)
A landlord's rental property needs a new kitchen, new bathroom, redecoration, new carpets and updated central heating before re-letting. No structural work. No planning or building regulations involved. Classification: light, a straightforward single-advance loan against current value. Typical rate: 0.55–0.65%/month for clean credit.
Rates & Costs
Rates reflect the complexity and risk of the project and the borrower's credit profile. Interest is most commonly retained, deducted from the gross loan at outset, so no monthly payments are required during the works.
| Borrower profile | Monthly rate | Max LTV |
|---|---|---|
| Clean credit, light refurbishment | 0.55–0.65% | 75% of current value |
| Minor adverse credit, light refurbishment | 0.65–0.75% | 70% of current value |
| Clean credit, heavy refurbishment | 0.65–0.75% | 75% of GDV |
| Adverse credit, heavy refurbishment | 0.75–1.0% | 65–70% of GDV |
In addition to the monthly rate, budget for an arrangement fee of 1–2% of the gross loan. For heavy refurbishment, the monitoring surveyor's costs (typically £2,000–£4,000 for multiple site visits) are also payable by the borrower. Include both in your project appraisal from the outset.
Compare on total cost, not headline rate
A lender offering 0.60%/month with a 2% arrangement fee may cost more overall than one offering 0.70%/month with a 1% fee, depending on the loan term. Always model the complete cost of finance before comparing products.
Which Do You Need?
In most cases, the classification is determined by your project, not by preference. Your works either include structural elements or they do not.
Where there is genuine flexibility (for example, a project that could be delivered cosmetically only (light) or with an extension (heavy)), that is a project decision first and a finance decision second. It is not possible to use light refurbishment finance for a heavy project, regardless of how the works are described. The lender's RICS surveyor will assess the scope independently.
Choose light refurbishment finance when:
- All works are cosmetic or non-structural
- No planning permission or building regulations are required
- You want funds released in a single advance with minimal process
- Your project timeline is 3–9 months
- Your exit strategy is sale or refinance to a standard buy-to-let mortgage
Choose heavy refurbishment finance when:
- Any structural works are involved: extensions, conversions, or load-bearing changes
- Planning permission or building regulations approval is required or has been obtained
- You need to borrow against the future GDV to make the project financially viable
- The project runs for 6 months or longer
- You are converting to a different use class or to an HMO
Not sure? Ask before you apply
If your project sits on the boundary, speak to a specialist broker before submitting. Applying to the wrong product type wastes time and triggers unnecessary credit searches. A broker can review the scope and confirm the correct classification without any formal application being made.
FAQs
My project is mostly cosmetic but includes one structural change: which do I need?
Heavy refurbishment. A single structural element (such as removing a load-bearing wall in an otherwise cosmetic project) triggers the heavy classification. Building regulations approval and a structural engineer's sign-off will be required for that element regardless of what else is being done. The lender's RICS surveyor will identify this during the valuation inspection.
Can I start with light refurbishment and switch to heavy if I decide to extend?
No. A light refurbishment bridge is a separate product from a heavy facility. If you decide mid-project to carry out structural works not in the original scope, you would need to refinance, incurring additional legal and valuation costs. Plan the full scope before drawdown and apply for the right product from the outset. If there is any possibility you will add structural works, apply for heavy refurbishment and draw only what you need initially.
Is a loft conversion always heavy refurbishment?
Yes. A loft conversion requires building regulations approval and structural engineering input for floor structure, steelwork, and fire separation. These requirements automatically place it in the heavy category, regardless of whether full planning permission is needed or whether the conversion proceeds under permitted development.
Does the lender decide the category, or do I declare it?
You declare the category when making your enquiry, but the lender verifies it independently through the RICS valuation inspection and their review of your scope of works. If the surveyor concludes the project is heavier than declared, the lender will either restructure to a heavy facility on different terms or decline the application. Accurate self-classification is strongly in your interest.