What is the average rear extension approval rate in the UK?

Across 160 councils and 481,265 decisions, the average approval rate is 90.2%. But rates vary enormously by council and location.

Which council has the highest rear extension approval rate?

Fareham at 99.8% based on 479 decisions.

How many rear extension applications get refused?

Of 481,265 decisions nationally, 68,739 were refused. That is roughly 1 in 7 applications.

Rear Extension — What Are Your Chances? UK Approval Rates (March 2026)

10 Best Councils for Rear Extensions

These councils approve rear extension applications at the highest rate. But remember — a high council average can hide wards where refusal rates are double the headline figure.

#	Council	Decisions	Refused	Rate
1	Fareham	479	1	99.8%
2	South Lanarkshire	4,892	28	99.4%
3	Carlisle	517	5	99.0%
4	Gosport	483	5	99.0%
5	Stockton-on-Tees	301	3	99.0%
6	Mansfield	634	7	98.9%
7	Broadland	650	8	98.8%
8	Torridge	316	4	98.7%
9	South Norfolk	566	8	98.6%
10	Bromsgrove & Redditch	390	6	98.5%

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10 Hardest Councils for Rear Extensions

These councils refuse rear extensions at the highest rate. If you're planning a rear extension in one of these areas, checking your local data first could save you thousands in wasted fees.

#	Council	Decisions	Refused	Rate
1	Cardiff	265	98	63.0%
2	Greenwich	5,373	1,812	66.3%
3	Brent	12,106	3,314	72.6%
4	Barking & Dagenham	2,715	745	72.6%
5	Kingston	7,226	1,807	75.0%
6	Waltham Forest	7,930	1,959	75.3%
7	Lewisham	4,494	1,104	75.4%
8	Barnet	17,196	4,145	75.9%
9	Hillingdon	9,930	2,229	77.6%
10	Thurrock	3,518	776	77.9%

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All 160 Councils Ranked for Rear Extensions

#	Council	Decisions	Approved	Refused	Rate
1	Fareham	479	478	1	99.8%
2	South Lanarkshire	4,892	4,864	28	99.4%
3	Carlisle	517	512	5	99.0%
4	Gosport	483	478	5	99.0%
5	Stockton-on-Tees	301	298	3	99.0%
6	Mansfield	634	627	7	98.9%
7	Broadland	650	642	8	98.8%
8	Torridge	316	312	4	98.7%
9	South Norfolk	566	558	8	98.6%
10	Bromsgrove & Redditch	390	384	6	98.5%
11	Stirling	481	474	7	98.5%
12	North East Lincolnshire	374	368	6	98.4%
13	Lincoln	941	925	16	98.3%
14	Cheltenham	2,399	2,351	48	98.0%
15	Cornwall	323	316	7	97.8%
16	County Durham	1,451	1,419	32	97.8%
17	Winchester	898	878	20	97.8%
18	Tamworth	1,117	1,091	26	97.7%
19	Knowsley	1,385	1,348	37	97.3%
20	Plymouth	1,196	1,164	32	97.3%
21	Rushmoor	891	867	24	97.3%
22	South Tyneside	681	662	19	97.2%
23	Rugby	1,057	1,025	32	97.0%
24	Derby	1,460	1,413	47	96.8%
25	Doncaster	1,637	1,583	54	96.7%
26	Gateshead	1,377	1,332	45	96.7%
27	Adur & Worthing	2,856	2,758	98	96.6%
28	Wakefield	1,770	1,707	63	96.4%
29	Aberdeen	701	675	26	96.3%
30	North East Derbyshire	1,103	1,062	41	96.3%
31	Basingstoke & Deane	1,799	1,730	69	96.2%
32	North Tyneside	1,244	1,195	49	96.1%
33	Lewes & Eastbourne	293	281	12	95.9%
34	Mid Sussex	1,182	1,134	48	95.9%
35	Forest of Dean	544	521	23	95.8%
36	Norwich	1,397	1,339	58	95.8%
37	Cotswold	2,282	2,181	101	95.6%
38	Sunderland	1,019	974	45	95.6%
39	West Oxfordshire	914	874	40	95.6%
40	Gedling	992	947	45	95.5%
41	Barnsley	3,843	3,666	177	95.4%
42	North Northamptonshire	542	517	25	95.4%
43	Darlington	443	422	21	95.3%
44	Horsham	2,125	2,025	100	95.3%
45	Tewkesbury	1,256	1,197	59	95.3%
46	Broxtowe	1,363	1,297	66	95.2%
47	Cannock Chase	483	460	23	95.2%
48	Telford & Wrekin	2,582	2,457	125	95.2%
49	Torfaen	538	512	26	95.2%
50	Bath & NE Somerset	5,021	4,777	244	95.1%
51	North Somerset	3,146	2,981	165	94.8%
52	Flintshire	575	544	31	94.6%
53	Dudley	4,051	3,822	229	94.3%
54	East Cambridgeshire	1,288	1,213	75	94.2%
55	Nottingham	977	920	57	94.2%
56	Test Valley	703	662	41	94.2%
57	Dorset	708	666	42	94.1%
58	York	2,435	2,292	143	94.1%
59	Lancaster	354	332	22	93.8%
60	Brighton & Hove	506	474	32	93.7%
61	Stevenage	1,128	1,057	71	93.7%
62	Warwick	3,625	3,396	229	93.7%
63	Great Yarmouth	378	353	25	93.4%
64	South Downs	939	876	63	93.3%
65	Camden	3,282	3,059	223	93.2%
66	Solihull	1,279	1,192	87	93.2%
67	Cambridge	1,044	972	72	93.1%
68	Cheshire East	2,071	1,928	143	93.1%
69	Sandwell	2,809	2,613	196	93.0%
70	Swindon	1,075	1,000	75	93.0%
71	Wandsworth	5,992	5,572	420	93.0%
72	Ceredigion	337	313	24	92.9%
73	Dover	890	826	64	92.8%
74	Rotherham	778	721	57	92.7%
75	Chorley	856	793	63	92.6%
76	Hammersmith & Fulham	5,296	4,902	394	92.6%
77	Three Rivers	440	407	33	92.5%
78	New Forest	2,406	2,222	184	92.4%
79	Tonbridge & Malling	1,853	1,710	143	92.3%
80	Sheffield	1,561	1,440	121	92.2%
81	Southwark	3,757	3,462	295	92.1%
82	Isle of Wight	1,381	1,271	110	92.0%
83	Luton	1,839	1,691	148	92.0%
84	Thanet	5,791	5,315	476	91.8%
85	Manchester	2,381	2,181	200	91.6%
86	Exeter	1,020	933	87	91.5%
87	Wigan	590	540	50	91.5%
88	Rushcliffe	2,268	2,073	195	91.4%
89	Selby	789	721	68	91.4%
90	Lichfield	585	533	52	91.1%
91	Bristol	5,501	5,000	501	90.9%
92	Oldham	2,361	2,143	218	90.8%
93	South Gloucestershire	3,783	3,434	349	90.8%
94	Bury	1,150	1,042	108	90.6%
95	Trafford	5,917	5,352	565	90.5%
96	Kingston upon Hull	1,091	986	105	90.4%
97	Hastings	681	614	67	90.2%
98	Newport	643	579	64	90.0%
99	Reigate & Banstead	2,551	2,297	254	90.0%
100	Kensington & Chelsea	3,192	2,864	328	89.7%
101	Surrey Heath	1,177	1,055	122	89.6%
102	Calderdale	1,303	1,162	141	89.2%
103	Kirklees	5,890	5,256	634	89.2%
104	Oxford	1,277	1,139	138	89.2%
105	Portsmouth	2,254	2,010	244	89.2%
106	Dartford	1,944	1,733	211	89.1%
107	Leeds	10,080	8,973	1,107	89.0%
108	Liverpool	987	877	110	88.9%
109	Sefton	426	378	48	88.7%
110	Spelthorne	296	261	35	88.2%
111	Haringey	4,275	3,760	515	88.0%
112	Bradford	5,925	5,202	723	87.8%
113	Sevenoaks	1,735	1,522	213	87.7%
114	Westminster	3,068	2,691	377	87.7%
115	Glasgow	1,282	1,123	159	87.6%
116	Runnymede	3,487	3,055	432	87.6%
117	Epsom & Ewell	2,239	1,960	279	87.5%
118	Birmingham	13,248	11,547	1,701	87.2%
119	Gloucester	949	827	122	87.1%
120	Hart	2,121	1,836	285	86.6%
121	Newark & Sherwood	1,039	899	140	86.5%
122	Caerphilly	439	376	63	85.6%
123	Windsor & Maidenhead	1,934	1,652	282	85.4%
124	Hackney	3,697	3,142	555	85.0%
125	Castle Point	954	810	144	84.9%
126	Hounslow	26,504	22,511	3,993	84.9%
127	Tameside	958	813	145	84.9%
128	Slough	2,671	2,251	420	84.3%
129	Coventry	475	400	75	84.2%
130	Brentwood	3,747	3,150	597	84.1%
131	Ealing	22,565	18,748	3,817	83.1%
132	Hertsmere	924	767	157	83.0%
133	Swansea	604	500	104	82.8%
134	Bexley	7,902	6,527	1,375	82.6%
135	Richmond	6,906	5,682	1,224	82.3%
136	Bromley	10,946	9,001	1,945	82.2%
137	Lambeth	5,992	4,925	1,067	82.2%
138	Havering	8,298	6,773	1,525	81.6%
139	Guildford	3,726	3,035	691	81.5%
140	Merton	5,617	4,576	1,041	81.5%
141	Croydon	10,142	8,224	1,918	81.1%
142	Maldon	660	534	126	80.9%
143	Islington	11,660	9,405	2,255	80.7%
144	Tower Hamlets	1,827	1,470	357	80.5%
145	Sutton	6,821	5,419	1,402	79.4%
146	Enfield	9,329	7,347	1,982	78.8%
147	Newham	4,353	3,420	933	78.6%
148	East Hertfordshire	5,178	4,063	1,115	78.5%
149	Harrow	4,812	3,762	1,050	78.2%
150	Redbridge	12,628	9,847	2,781	78.0%
151	Thurrock	3,518	2,742	776	77.9%
152	Hillingdon	9,930	7,701	2,229	77.6%
153	Barnet	17,196	13,051	4,145	75.9%
154	Lewisham	4,494	3,390	1,104	75.4%
155	Waltham Forest	7,930	5,971	1,959	75.3%
156	Kingston	7,226	5,419	1,807	75.0%
157	Barking & Dagenham	2,715	1,970	745	72.6%
158	Brent	12,106	8,792	3,314	72.6%
159	Greenwich	5,373	3,561	1,812	66.3%
160	Cardiff	265	167	98	63.0%

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What the data tells us

1

Where you live changes everything. The gap between the best council (Fareham, 99.8%) and the worst (Cardiff, 63.0%) is 36.8%. Same project, completely different odds.

2

68,739 rear extension applications have been refused since 2020. Each one cost the homeowner time and money. Most of those refusals were predictable from the local data.

3

National averages hide local variation. Your council rate is useful context. Your ward rate is better. But the comparable decisions near your specific property are the only real predictor of your outcome.

Rear Extension Approval Rates Across the UK

Check Your Postcode for Approval Chances

10 Best Councils for Rear Extensions

10 Hardest Councils for Rear Extensions

Your council's approval rate is just the starting point

All 160 Councils Ranked for Rear Extensions

What the data tells us

The UK average is meaningless. Your street isn't average.

More national planning data