Conservation-area CGI and interior visualisation for Kensington and Chelsea schemes

An AVR is a visualisation prepared to the Landscape Institute Technical Guidance Note 06/19, with a documented relationship between the surveyed photograph, camera position, 3D model and proposed scheme so a planning officer can rely on it as evidence. A Kensington and Chelsea project usually needs an AVR rather than illustrative CGI when the proposal materially affects townscape, the setting of a heritage asset, a London View Management Framework view, a conservation-area roofline, or neighbour amenity in a sensitive setting. The Royal Borough planning consultant or design team typically sets the requirement at pre-application stage.

TGN 06/19 defines four visualisation types of increasing rigour. Type 1 is an annotated photograph that identifies the proposed location and visibility envelope without 3D modelling. Type 2 overlays a wireline or wireframe model on the surveyed photograph to show scale, position and form. Type 3 is a rendered photomontage or photowire that integrates material, lighting and context. Type 4 is a fully verified view, prepared with surveyed camera control, ground points and a registered 3D model so the geometry is scale-verifiable. The right type for a Kensington and Chelsea scheme is set by the planning consultant against the sensitivity of the view.

A TVIA is normally required when a Kensington and Chelsea scheme is large enough or visually sensitive enough that the planning officer needs structured evidence of townscape and visual effects. In RBKC that often covers schemes within or adjacent to a conservation area, near a listed building, visible from a London View Management Framework Designated View or Protected Vista, or affecting a sensitive roofline. The TVIA scope, viewpoints, receptors and methodology should be agreed with the planning consultant and townscape consultant at pre-application, with verified views or AVR Type 4 commissioned only after the viewpoint set is fixed.

Local Plan Policy CL7 is the Royal Borough of Kensington and Chelsea policy that controls residential basement development, supplemented by the Basements SPD adopted in April 2016. CL7 limits basement extent (typically a single storey), restricts construction beneath listed buildings, requires retention of garden ground and trees, and requires a Basement Impact Assessment from a chartered engineer covering ground, water, structure and construction logistics. CGI for a CL7 scheme should sit alongside the BIA, daylight and sunlight study and arboricultural report, showing the lightwell, garden loss, tree retention, neighbour amenity and street-facing character impact accurately rather than replacing the engineering evidence.

In practice almost every meaningful basement in Kensington and Chelsea needs full planning permission. RBKC made a borough-wide Article 4 Direction in April 2015 that removed permitted-development rights for basement extensions to single dwelling houses across the entire borough, in force from 28 April 2016, and Basement Policy CL7 imposes further controls. Households with listed buildings or properties inside conservation areas already lacked permitted-development scope for most basement work. Any CGI commissioned for a Kensington and Chelsea basement should therefore be scoped from the start as planning evidence, not as illustrative-only marketing.

A photomontage is a CGI composited into base photography to show a proposed scheme in a real London context. A verified view is a photomontage produced to AVR Type 4 methodology, with surveyed camera position, lens-matched photography, ground control points and a registered 3D model so the geometry is scale-verifiable rather than illustrative. Every verified view is a photomontage, but not every photomontage is verified. For Kensington and Chelsea heritage and townscape submissions, planning officers usually want the verified-view route on sensitive viewpoints and accept illustrative photomontage only on lower-sensitivity views or for design-stage discussion.

Cost varies with the technical rigour and evidence standard required for the intended use. Illustrative interior and exterior CGI views are quoted per package, while Accurate Visual Representations (AVR) and verified views with surveyed control reflect the additional survey, camera-matching, and reporting requirements. Final fees depend on viewpoint count, model complexity, townscape context requirements, and the specific planning or marketing decision the visuals need to support. Send the drawings and viewpoint brief and we will provide a bespoke quote against the actual scope.

A verified view needs surveyed camera positions captured by GNSS or total station, base photography taken with a lens whose focal length matches the assessment requirement (TGN 06/19 specifies a 50mm equivalent for Type 1 single-frame views), the project 3D model in a coordinate system registered to the survey, and a set of OS or LIDAR context data to lock building lines and ground levels to the real world. Photography should be taken in agreed light and weather conditions, ideally at the time of year and time of day relevant to the planning argument. For Kensington and Chelsea views inside the LVMF, viewpoints and methodology should be agreed with the planning consultant before the photographer goes to site.

The Royal Borough of Kensington and Chelsea operates several Article 4 Directions including a borough-wide direction on basement extensions to single dwelling houses (made 15 April 2015, in force 28 April 2016), directions on demolition in conservation areas, and a Class E to C3 commercial-to-residential change of use direction made 20 July 2021 and modified by the Secretary of State on 22 July 2022. An Article 4 Direction removes permitted-development rights, so a project that would normally proceed without planning permission elsewhere may need a full application here. CGI for an Article 4 site usually has to be commissioned earlier and at higher fidelity, framed as planning evidence with conservation-area and heritage-setting context rather than as marketing imagery.

A heritage statement is the document that assesses how a proposal affects the significance and the setting of a heritage asset, and is normally required for listed-building consent and for any Kensington and Chelsea application that affects a listed building or its setting. The CGI should visualise the same alterations the heritage statement describes, using the same fabric vocabulary (retained, repaired, replaced, new intervention), so the planning officer can read the two documents together. We recommend producing the visuals after the heritage statement is drafted, so the imagery shows the agreed conservation strategy rather than an earlier design option that the heritage consultant later changed.