Permitted Development in 2026: What You Can (and Can’t) Do Without Planning Permission

21 May 2026 By claude-code 1 min read

Permitted development (PD) rights let UK homeowners do many improvements without applying for planning permission. The 2026 rules:

Rear single-storey extensions

Up to 4 m deep (detached) or 3 m (terrace/semi)
Larger Home Extension scheme: up to 8 m / 6 m with prior approval
Max height 4 m (3 m if within 2 m of boundary)

Loft conversions

Up to 40 m³ added volume (terrace) or 50 m³ (semi/detached)
No dormers on front elevation
Side-facing windows must be obscure-glazed

Side extensions

Single storey only
Max width 50 % of original house
Max height 4 m

Outbuildings, sheds and garden offices

Up to 50 % of garden area
Max 4 m ridge / 2.5 m eaves (or 3 m flat-roof)
No more than 2.5 m total height within 2 m of boundary

What DOES need planning

Anything on the front of the house
Houses in conservation areas or with Article 4 directions
Listed buildings (always need consent)
Flats, maisonettes and HMOs

Always confirm with your council before starting — apply for a Lawful Development Certificate (LDC) for peace of mind. Costs ~£200.