Barnet planning guide: Policy CDH05, the tree and bat rows, and the householder checklist
Barnet's householder checklist looks short, but three of its rows are easy to miss: the drawings must show every tree within 15 metres of the extension, a Fire Safety exception statement may be asked for, and removing part of a roof calls for a bat roost assessment. Underneath sits Policy CDH05 in the Local Plan adopted on 4 March 2025. This guide reads both and says which report answers each row. If you want the constraints for your address first, a planning constraints report costs £19.
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Policy CDH05 in the 2025 Local Plan
Barnet's Local Plan 2021-2036 was adopted on 4 March 2025, according to the council's adoption statement, and the council's Local Plan page says it replaces the 2012 version. Extensions are governed by Policy CDH05. Our Barnet house extension drawings page covers the drawing set.
The policy says the council “will support proposals for extensions to any building” that complement the character of the building “particularly in terms of style, form and materials”, are “subordinate to the existing building in terms of size, scale and/or height”, and “incorporate a roof profile sympathetic to the existing property”. It also asks that they “avoid significant adverse impacts on the sunlight/daylight to neighbouring properties”, respect the privacy of surrounding residents and not reduce amenity space below the standards in its Table 10.
CDH05 sets tests rather than a depth in metres, so the drawings carry the argument. Elevations and sections that show the height and roof against the neighbours, and window positions on both sides, are what let an officer apply the sunlight, outlook and privacy tests quickly. Our planning permission page for Barnet covers the wider application.
Barnet Council Planning Guide
from £19
Every price is the full fixed fee you pay. No VAT is charged. Council application fees are paid to the council separately.
What you get
- Policy CDH05 of the Local Plan 2021-2036, quoted from the plan
- The householder checklist: national and Barnet essential rows, and the ones that may be required
- Why the drawings must show trees within 15 metres, and when a tree survey is asked for
- When a heritage statement, flood assessment, bat assessment or daylight report comes in
- Each report your project triggers, linked to its fixed-fee page
- A planning constraints report for your address from £19
- Map the trees
Plot every tree within 15 metres of the extension on the block plan and drawings, on the site or next door.
- Draw to the scales
Floor plans, elevations and sections go at 1:50 or 1:100; the block plan at 1:200 or 1:500.
- Check the roof
If part of the roof is removed, ask whether a bat roost assessment will be needed.
- Keep files small
Electronic files should be PDF, named, and no larger than 20MB each.
What the householder checklist asks for
Barnet's householder checklist is Validation Checklist 1, Works to a dwelling house, reached from the council's validation requirements page, which is marked last updated 2 June 2026. It says “The level of information required for a valid application will depend on the scale and nature of the proposal”, and that the local assessments can be folded into a single planning statement when the issues are straightforward.
The national rows are the form, which must carry data for the Greater London Authority, the ownership certificate, the fee, an Ordnance Survey location plan at 1:1250 with the boundary in red and other land you own in blue, and the plans. A Design and Access Statement is asked for where the work adds 100 square metres or more of floor space in a conservation area, or where the property is a listed building.
Barnet adds its own essential rows. Every application needs the CIL additional information form, drawings with a scale bar of 0 to 5 or 0 to 10 metres and a reference number and the site address on each sheet, floor plans, elevations, roof plans and sections at 1:50 or 1:100, and a block plan at 1:200 or 1:500 with boundaries, adjoining buildings and trees within 15 metres. Electronic files should be PDF, named, and under 20MB each. Our location and block plans page covers the plans, and the CIL form page covers the form.
The council's conservation areas page lists 16 areas, from College Farm and Finchley Church End to Totteridge, Watling Estate and Wood Street, including Hampstead Garden Suburb and Golders Green.
Trees within 15 metres, bats and the other “may be required” rows
The drawings row says to show “trees within 15m of extension”. If a tree stands within 15 metres of the development, on the site or next door and including street trees, the list moves from a mark on the plan to a tree survey and arboricultural statement. A tree survey for planning is prepared by a specialist we coordinate.
The ecological row is the one that catches loft and roof work. Development proposing the removal or partial demolition of a roof “will require a Bat Roost Assessment”. Ask early, because bat work depends on the time of year; a bat survey for planning is arranged through a specialist partner. The same group of rows asks for a parking layout where a garage becomes a habitable room, and a fire safety reasonable exception statement, which our fire safety statement page covers.
Flood zones, daylight and sunlight
A flood risk assessment that follows the standing advice for minor extensions is asked for where the site is in flood zone 2 or 3, or within 20 metres of the top of the bank of a main river. Evidence of sustainable drainage is asked for where impermeable surfacing increases or drainage patterns change, which is the row a rear extension that covers lawn can trigger. A flood risk assessment is the document, and a planning constraints report shows your zone first.
The daylight and sunlight row is “required only in exceptional cases where development may have significant impacts on neighbouring properties”, and the council asks you to seek advice from the planning service. It is not a standard householder item, but where a deep or tall extension sits close to a neighbour's window, a daylight and sunlight report is the evidence that answers CDH05's sunlight and daylight test.
Conservation areas and Article 4
The council's conservation areas page lists 16 areas, from College Farm and Finchley Church End to Totteridge, Watling Estate and Wood Street, including Hampstead Garden Suburb and Golders Green. It says 10 of them are covered by Article 4 directions, which means some work you could usually do without planning permission needs consent, and that it is an offence to demolish, alter or extend a building in a conservation area without consent.
The checklist asks for a heritage statement for extensions to listed buildings. For minor works to locally listed buildings and buildings in a conservation area, the heritage issues can sit in the Design and Access Statement where one is required, and otherwise a Heritage Statement is needed. Proposed landscaping is also asked for in conservation areas. Our heritage statement page and design and access statement page cover the documents.
Building regulations and party walls
Barnet's building control pages set out when approval is needed, how to apply by full plans or building notice, site inspections, charges, and a searchable building control archive of drawings and completion certificates. The archive is a quick way to find out whether an earlier extension on your house was ever signed off. Planning permission and building regulations are separate, so a planning decision does not replace a building control application. Our building regulations reports guide sorts the reports by project, and the Barnet building regulations drawings page covers the set.
The Party Wall etc. Act 1996 is national law that runs beside planning. Where you build on or near a shared wall, our party wall services guide explains the notices to neighbours.
Sources
Every figure on this page, where it comes from and a link to the original.
| Figure | Source | Link |
|---|---|---|
| 4 March 2025 | Barnet Local Plan Adoption Statement: (source wording: "On 4 March 2025 Barnet Council adopted a new Local Plan.") | www.barnet.gov.uk |
| 2 June 2026 | Barnet validation requirements page (householder, full, outline): (source wording: "Last updated 2 June 2026") | www.barnet.gov.uk |
| Policy CDH05 | Barnet Local Plan 2021-2036 Policy CDH05: Extensions: (source wording: "Are subordinate to the existing building in terms of size, scale and/or height") | www.barnet.gov.uk |
| 15 metres | Barnet Validation Checklist 1 (works to a dwelling house): (source wording: "showing trees within 15m of extension") | www.barnet.gov.uk |
| 1:200 or 1:500 | Barnet Validation Checklist 1: (source wording: "Block plan (1:200 or 1:500)showing boundaries, other buildings on the site, trees within 15m and buildings onadjoining sites") | www.barnet.gov.uk |
| 20MB | Barnet Validation Checklist 1: (source wording: "individual file sizes should not exceed20MB, should be in PDF format and be named") | www.barnet.gov.uk |
| 100 square metres | Barnet Validation Checklist 1, Design and Access Statement: (source wording: "involves additional floor space of 100 sq m or more in a conservation area, or The property is a listed building") | www.barnet.gov.uk |
| flood zone 2 or 3; 20 metres | Barnet Validation Checklist 1, Flood Risk Assessment: (source wording: "required where location in flood zone 2 or 3.within 20m of the top of the bank of a mainriver") | www.barnet.gov.uk |
| 16 | Barnet conservation areas page: the page lists sixteen named conservation areas from College Farm to Wood Street (our count of the names listed) | www.barnet.gov.uk |
| 10 | Barnet conservation areas page: (source wording: "Within Barnet there are 10 conservation areas that are either covered by or have article 4 directions in force.") | www.barnet.gov.uk |
The council's own pages
Every report on this page, with its fixed fee
| Report | Fixed fee | What it is |
|---|---|---|
| Planning constraints report | £19 | Conservation area, listing, flood zone and Article 4 checked for your address Written up on fixedfeeplans.co.uk. |
| House extension drawings | Free | Plans, elevations and sections at the scales the checklist names |
| Location and block plans | Free | The 1:1250 location plan and the block plan with trees within 15 metres |
| Tree surveys for planning | £445 | Where a tree stands within 15 metres of the work, including street trees Written up on www.propertyarchitecture.co.uk. |
| Bat surveys for planning | £495 | Asked where part of a roof is removed or altered Written up on www.propertyarchitecture.co.uk. |
| Heritage statements | £595 | For listed buildings, locally listed buildings and conservation areas Written up on fixedfeeplans.co.uk. |
| Design and access statements | £245 | At 100 square metres or more in a conservation area, or for a listed building Written up on fixedfeeplans.co.uk. |
| Flood risk assessments | £395 | In flood zone 2 or 3, or within 20 metres of a main river bank Written up on fixedfeeplans.co.uk. |
| Fire safety statements | £135 | The reasonable exception statement the checklist lists Written up on fixedfeeplans.co.uk. |
| Daylight and sunlight reports | £895 | Asked only in exceptional cases, where neighbours may be significantly affected Written up on www.propertyarchitecture.co.uk. |
| Building regulations reports | £225 | Which building regulations report fits your project |
| Party wall services | £45 | Notices under the Party Wall etc. Act 1996 for semis and terraces |
Questions people ask
Does Barnet have a maximum depth for a rear extension?
Why does Barnet ask for trees within 15 metres on my drawings?
Do I need a bat survey for a loft conversion in Barnet?
When does Barnet ask for a Design and Access Statement?
Which Barnet validation checklist applies to my application?
Photographs: David Howard (CC BY-SA 2.0).
