Havering planning guide: the extensions SPD, the 45 degree angle and what Checklist 001 asks of your drawings

The 2011 extensions guide still sets the numbers

Havering's adopted documents page lists Residential Extensions and Alterations 2011 among its current supplementary planning documents. The document is marked “Adopted March 2011”. For a single storey rear extension, paragraph 5.3 says “houses can be extended from the rear wall of the original dwelling by up to 3 metres in depth for a terrace house and up to 4 metres in depth for a semi-detached or detached dwelling”. Any greater depth “should be within an angle of 45 degrees, taken from the 3 metre or 4 metre dimension on the property boundary”. A flat-roofed single storey extension should generally be no more than 3 metres high, to avoid loss of daylight or sunlight next door.

Two storeys is stricter. Paragraph 5.13 asks for a two storey rear extension to be set in at least 2 metres from the common boundary with an attached dwelling and to project no more than 3 metres, with up to 4 metres in exceptional local circumstances. For side extensions, paragraph 6.6 asks for a first floor to be set back at least one metre from the front wall, to avoid a terracing effect, and paragraph 6.8 says side extensions “will not be permitted where they break a 45 degree line” taken from the sill of a primary original habitable-room window in the neighbour's side wall. Our Havering planning permission page and rear extension drawings apply these measures.

The Local Plan of 17 November 2021: Policies 7, 28 and 32

The council's adopted documents page says approval for the Havering Local Plan 2016 to 2031 was received at full council on 17 November 2021. Policy 7, Residential design and amenity, supports development that does not cause “unacceptable overlooking or loss of privacy or outlook” or “unacceptable loss of daylight and sunlight”. Those two phrases are what an objection from next door will quote, and they are why the elevations need the neighbours' windows and levels.

Policy 28 on heritage assets supports well designed development in a conservation area or its setting that “preserves, enhances or better reveals the character and appearance of the area”, and alterations or extensions to a listed building that would not harm its significance. Policy 32 on flood management is covered below. Our heritage statement page covers the document Policy 28 leads to.

Flood zones, drainage and trees

Checklist 001 asks for a flood risk assessment for all development in Flood Zones 2 and 3, including land benefiting from defences. Policy 32 goes further: the council will require site-specific assessments on sites where drainage problems have been identified by the council, in the Washlands Flood Storage Area, and where it judges one necessary as Lead Local Flood Authority. It also asks for sustainable drainage systems to reduce surface water runoff unless there are practical reasons not to. The plan notes that Havering has “a large proportion of London's floodplains”. Our flood risk assessment page and drainage statement page cover the documents, and a planning constraints report shows your flood zone first.

The tree row asks for a survey or arboricultural method statement where trees or hedges on the site or on adjacent land could be affected, to BS 5837 and BS 8545, showing species, spread, height, position and condition, which trees come down and how the rest are protected. See our tree survey for planning page.

Daylight, basements and the structural survey

A daylight and sunlight assessment is asked for “any application where there is a potential adverse impact” on the daylight and sunlight of adjoining properties or their gardens, prepared to the BRE guide BR 209 (2022 edition). A basement needs a Basement Impact Assessment, which can sit within the flood risk assessment or structural survey, and a structural survey by a chartered engineer. A structural survey is also asked for structural alterations or substantial demolition of a listed building or one in a conservation area. A basement feasibility visit comes before drawings, and a daylight and sunlight report answers the first row.

Building control and the party wall

Havering's building control service takes full plans and building notice applications, regularisation applications for unauthorised work, site visit bookings and progress tracking, and has a page on the Building Safety Levy. Our building regulations reports guide sorts the drawings, a drawing check, comments answered and regularisation. The 2011 SPD itself reminds applicants of the Party Wall Act, and our party wall services guide explains the notices to neighbours.