James Brown House, 18 Finch Road, Douglas
Not marked as sole agency on the original listing, so this property may also be marketed by other agents not captured in this data.
This looks like a registered building
A property matching this listing's name appears on the Isle of Man's Protected Buildings Register, registered on 27 Jul 1987. Registration is a legal constraint, not a label: altering, extending or demolishing a registered building requires Registered Building Consent under the Town and Country Planning Act 1999, in addition to ordinary planning permission, and that applies to work an unregistered house would not need permission for at all.
Matched by building name against the public register, not by a shared identifier — no such identifier exists. Treat it as a strong prompt to check, not as proof: confirm against Planning and Building Control's own register before you offer, and ask your advocate. Equally, nothing here proves a property is NOT registered — see the full register.
What would improving it be worth?
Value added is the extra floor area priced at £3,229/m² — the midpoint asking price per m² among 6 Douglas properties currently for sale that publish a floor area. Cost uses real Isle of Man build rates: £4,000–£6,000/m² new build and £2,000–£4,000/m² refurbishment, depending on quality. Net is against the mid rate. The last column is how often Isle of Man actually grants that kind of application.
| Improvement | Value it might add | Likely cost | Net | Granted |
|---|---|---|---|---|
| Add a bedroom (single-storey extension) A modest double plus circulation, built new. ~14 m² |
£45,207 | £52,500 14 m² · mid spec new build range £42,000–£63,000 |
−£7,293 | 0% (314) |
| Loft conversion with a bedroom Works inside an existing roof, so it prices as refurbishment rather than new build — which is why it usually wins. ~20 m² |
£64,582 | £41,000 20 m² · mid spec refurb range £33,000–£50,000 |
+£23,582 | 0% (46) |
| Two-storey extension Roughly 14 m² on each of two floors. ~28 m² |
£90,415 | £105,000 28 m² · mid spec new build range £84,000–£126,000 |
−£14,585 | 0% (66) |
| Garage, annexe or outbuilding Detached space is worth less per m² than main-house floor area. ~18 m² |
£34,874 | £67,500 18 m² · mid spec new build range £54,000–£81,000 |
−£32,626 | 0% (199) |
Two things it cannot see. First, it prices floor area at the local average rate — it doesn't know your plot, your roof, your outlook, or whether an extension is physically possible; nor whether your street has a ceiling price that no amount of extending beats. Second, the rate comes from asking prices of other properties currently for sale, because the Isle of Man's sold register records no floor areas at all — so it reflects what sellers ask, not what buyers paid.
The obvious alternative method is worse, which is why it isn't used here: comparing a typical 3-bed with a typical 4-bed suggests a bedroom is worth around £430,000 island-wide. It isn't — a 4-bed is generally a bigger house on a bigger plot, so that figure measures the mix of what's for sale, not the value of adding a room.
Before spending anything, get a builder's quote and talk to an architect — what work of this kind actually gets approved here shows how often applications like yours succeed, and on what grounds the refusals go.
Building work on this property
Same estimate model this site uses on its planning pages (UK cost ranges with the Isle of Man's 18% uplift) — a rough starting point, not a quote. Always get quotes from an Isle of Man builder before budgeting.
See also all Isle of Man property professionals — architects, surveyors, mortgage brokers and trades.
Sale history
No prior sale found in the Isle of Man property register for this address.
Planning history
No planning application found in this site's planning dataset for this address.
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