JG Architecture Ltd

Award-winning chartered practice led by Director James Gavey (12+ years in the industry); Unit 1 Cobo Business Centre, Clos De Salle, Route De Carteret, Castel. Extensions, conversions and new builds through to larger commercial design; added RIBA Chartered Architect Mike McLellan to the team in 2025. Not RICS-regulated. 61 applications as agent 2022-2025.

Extensions, Conversions & New Builds – Guernsey

JG Architecture Ltd’s own words, from jga.gg . Quoted as published — this site neither vets nor endorses any firm.

Images published by JG Architecture Ltd on their own website.

What they specialise in

Work types this firm files more often than the island does — "×3.9" means nearly four times the rate that type appears across all Guernsey applications. Ordered by the value of the work, not the ratio, so the jobs that actually pay come first: a rebuild at ×1.7 is worth far more than window replacement at ×2.5.

"Est. value of this work" is the typical job cost for that type multiplied by how many they filed — a rough sense of where the practice's money sits, not their fees or their turnover. Needs at least 12 applications on file and 3 in the category before a ratio is shown, so a small practice can't look like a specialist on two lucky jobs. Classified from each application's own wording, so a minority will sit in a category a human would read differently.

The properties they work on

Of 61 applications this firm filed, 31 are tied to a later recorded sale of the same address, and 29 of those carry a real price. The midpoint is £1,193,840, each carried forward to 2026 money at the island index. Most of their filed work is in St Peter Port (15), Castel (10), St Martin (8).

2 matched sales recorded at a nominal £1–£100 were excluded — those are family or trust transfers, not market prices. Matching is by address and parish against the States register, not a shared ID, so a shared house name can mismatch. It tells you the value bracket this firm operates in; it is not their fee and not a claim about any individual job.

Work-type mix

Classified from each application's own description text, most common first — the same keyword model this site's planning cost estimates use. Select a type to filter the applications below.

Typical cost of work

£32,193–£59,976 average, estimated per application from its own description text using this site's planning cost model — a rough guide only, not a quote from JG Architecture Ltd or a reflection of what any specific job actually cost, and it does not include design fees. Each row below also carries an estimate at the prices of the year it was filed, deflated with the island house-price index — a proxy, since that index tracks house prices rather than construction costs and the two genuinely diverge (materials spiked in 2021–22 well beyond house-price growth). No Guernsey construction-cost index is published, so this is the best basis available, and it is an estimate on top of an estimate. 8 demolish-and-rebuild applications excluded from the average — that category prices per m² of the rebuild, which isn't recorded per application here.

61 planning applications as agent — real cross-references

Success rate on decided applications: 90% granted (55 granted, 6 refused, of 61 decided — pending/withdrawn excluded)