HMO Planning Permission in Barnet: The 2026 Checklist
If you are a landlord or developer looking to convert a family home (Class C3) into a small House in Multiple Occupation (Class C4) in Barnet, start from one fact: since 29 May 2016, Barnet has operated a borough-wide Article 4 Direction removing the permitted development right for that change of use. In Barnet, planning permission is always required for a C3→C4 conversion — anywhere in the borough, at any scale from three sharers up.
This is the checklist we use on Barnet HMO applications, set against the policies and standards that decide them.
The policy framework — what your application is judged against
The London Plan (2021). The strategic layer above the borough's policies: Policy H9 (the role and protection of HMOs in meeting housing need), Policy H8 (loss of existing housing), Policy D6 (housing quality and space standards) and Policy D12 (fire safety). As everywhere, Policy H16 governs 50+ unit co-living schemes and is not the regime for a small C4 conversion.
Barnet's adopted Local Plan (2023) — Policy HOU04. Small HMO applications are considered against Policy HOU04 (Specialist Housing), with detailed guidance on conversions and HMOs in Barnet's Residential Design Guidance SPD. The tests are the familiar Archetype-A set: the quality of the accommodation proposed, the effect on neighbouring amenity and local character, and the cumulative impact of shared housing in the surrounding area. Barnet's Local Plan is recently adopted, so unlike some neighbours there is no imminent policy changeover to track — the rules below are the rules for the foreseeable.
Barnet's Standards for Houses in Multiple Occupation. This is the document many applicants miss. Barnet has adopted the national minimum standards into its own published Standards for Houses in Multiple Occupation — and applies them to all HMOs in the borough, whether licensable or not. Planning officers assess layouts against it, and licence conditions are built on it, so it effectively sets your floor plan (see the checklist below).
Licensing — separate from planning, and layered. Barnet operates borough-wide additional licensing (HMOs of 3+ people in 2+ households, beyond the mandatory 5+ regime) plus selective licensing in designated areas following its Phase 2 designation. Planning permission is not a licence and a licence is not planning permission — budget for both, in parallel, from day one.
1. The location test (Policy HOU04 + Residential Design Guidance SPD)
Before commissioning drawings, test the site: would the conversion harm the character of the street or tip the cumulative concentration of shared housing in the locality? Barnet's case for its borough-wide Article 4 was explicitly about managing the distribution of HMOs, and officers apply that lens. Check the immediate area's planning history for HMO approvals and refusals — the pattern tells you how the policy is being applied on your street. Conservation areas carry the usual additional presumption toward preserving character.
2. Internal space standards (Barnet HMO Standards + London Plan D6)
Barnet's Standards adopt the national mandatory minimum room sizes, applied to every HMO in the borough:
Single room (one person over 10): 6.51 m²
Double room (two persons over 10): 10.22 m²
Room for a child under 10: 4.64 m² — and no room below 4.64 m² may be used for sleeping
Floor area where the ceiling height is below 1.5 m does not count
Treat these as the legal floor, not the design target — under-sized rooms fail twice, first at planning (accommodation quality under HOU04 and London Plan D6) and again at licensing.
3. Kitchens, bathrooms and amenity (Barnet HMO Standards)
The Standards require proportionate cooking and washing provision for the number of sharers, with one practical rule worth designing around: personal washing facilities and WCs must be available to occupants 24 hours a day — layouts that route one tenant's bathroom access through another's room, or rely on facilities in a lockable annexe, fail. Provide bathrooms, WCs and kitchen capacity scaled to occupancy (the conventional benchmark is one set of facilities per five sharers), with adequate communal space for a shared house. Confirm the current ratios against the published Standards before fixing the layout.
4. External requirements
Refuse and recycling: storage for the intensified use that doesn't blight the street scene or obstruct footways.
Parking and cycle storage: demonstrate the conversion won't create on-street parking stress — a live issue in Barnet's suburban streets — and provide secure, step-free cycle storage; we aim for one space per bedroom.
Amenity space: retain usable private garden space proportionate to the occupancy.
5. Management and safety (London Plan D12)
Where intensification is significant, submit a fire safety strategy in line with London Plan Policy D12, designed to the current BS 9991:2024 code; stack compatible rooms to manage noise; every habitable room needs natural light and ventilation. Barnet's Standards apply to the management of the property in operation, not just its layout on paper.
What it costs
The statutory fee for a C3→C4 change of use application is £610 from 1 April 2026 — £701 submitted via the Planning Portal with its service charge. Licensing fees sit on top under the additional or mandatory scheme. Against the income delta of a compliant shared house, these are transaction costs — the expensive outcome in Barnet is the refused application or the unauthorised conversion, not the fees.
Already running an HMO in Barnet?
If your C4 use predates 29 May 2016 and has continued since, the use is lawful — but after nearly a decade, the evidence is what fades. A Lawful Development Certificate (Existing Use) converts "we've always run it as an HMO" into conclusive proof, usable with enforcement officers, lenders and buyers. A use that began after the direction without permission needs ten years' continuous use before it can be certificated — take advice before anything interrupts the clock.
Common pitfalls to avoid
Assuming permitted development still applies — it went borough-wide in 2016.
Designing to the national room minimums without checking Barnet's Standards apply to every HMO, licensed or not.
Ignoring cumulative-impact signals from the street's planning history.
Treating the licence as planning permission, or vice versa.
Submitting non-compliant drawings — scale bars, waste storage and elevations included.
Designing for compliance in Barnet
Barnet pairs a long-established borough-wide Article 4 with a standards document that reaches every shared house in the borough. Securing approval is about designing to HOU04, the Residential Design Guidance and the HMO Standards together — and evidencing the neighbour-impact points before an objector raises them. The wider London context — which boroughs require permission, and what it costs — is in our complete London HMO guide; the deepest comparison point is our neighbouring Enfield checklist.
Bashkal specialises in residential conversions across London, and we manage Barnet C3→C4 applications end to end — feasibility and concentration check, compliant drawings, planning statement and submission, with the licensing position alongside. If you're weighing up a Barnet property, contact us for a technical appraisal before you commit.
Verified 5 June 2026 against: the Barnet HMO Article 4 Direction (borough-wide, in force 29 May 2016); Barnet Local Plan (2023) Policy HOU04 and the Residential Design Guidance SPD; Barnet's Standards for Houses in Multiple Occupation; Barnet's additional and selective licensing schemes; and the Planning Portal fee schedule (1 April 2026). Confirm the current position for a specific property before relying on this guide.
