Question 1

How Can I See What My House Will Look Like with an Extension?

Accepted Answer

The clearest way to see your proposed extension before construction begins is to commission a 3D CGI visualisation from an architectural visualisation studio. The studio takes your architect's drawings, RIBA Stage 2 or Stage 3 design information, and produces photoreal exterior images showing the extension in its surrounding context, including accurate materials, shadows, and neighbouring buildings.

Question 2

What Is CGI in House Extension Planning?

Accepted Answer

CGI stands for computer-generated imagery. In the context of a house extension planning application, it means a photorealistic 3D image produced from your architect's drawings and submitted alongside the standard drawing pack to show the local planning authority how the finished extension will look.

Question 3

What Drawings Do I Need for a House Extension Planning Application?

Accepted Answer

A standard UK householder planning application for an extension requires a location plan, a site plan showing the existing and proposed footprint, and a set of architectural drawings including existing and proposed floor plans, elevations, and a section. Most local planning authorities also expect a Design and Access Statement.

Question 4

How Much Does a House Extension Visualisation Cost?

Accepted Answer

A single photoreal exterior image of a straightforward single-storey rear extension typically costs between £350 and £600. A two-storey or wrap-around extension requiring two or three camera angles runs from £600 to £1,200. Where a verified view is needed for a conservation area, costs often reach £1,500 or more.

Question 5

What Does a 3D Render of a House Extension Show?

Accepted Answer

A 3D render shows the proposed extension as it will appear once built, viewed from one or more agreed external camera positions. It includes the extension's facade materials, window and door frames, roof covering, any visible landscaping, and the surrounding context including the existing house and neighbouring properties.

Question 6

Can I Draw Up My Own Plans for a House Extension?

Accepted Answer

There is no legal requirement in England to use a qualified architect or architectural technologist to prepare planning drawings. However, poorly prepared drawings cause validation failures and delays. Building regulations drawings must demonstrate compliance with Parts A, B, C, L, and other relevant parts of the Building Regulations.

Question 7

How Much Does It Cost to Have Plans Drawn for a House Extension?

Accepted Answer

Planning drawings for a single-storey rear extension from an architectural technologist typically cost £1,200 to £2,000. A two-storey or side-return extension runs from £1,800 to £3,500. A full RIBA service including planning, building regulations, and contract administration typically represents 10 to 15 percent of the build cost.

Question 8

What Is the 50% Rule for House Extension?

Accepted Answer

The 50% rule is a permitted development limit set out in Schedule 2, Part 1, Class A of the Town and Country Planning (General Permitted Development) (England) Order 2015. It states that any extension built under permitted development must not result in buildings covering more than 50% of the area of the original curtilage.

Question 9

Do I Need Planning Permission for a House Extension?

Accepted Answer

Many house extensions in England can be built without a planning application under permitted development rights, provided they meet the size and siting limits in Schedule 2, Part 1 of the GPDO. A single-storey rear extension can extend up to four metres from a detached house, or three metres for a semi-detached or terraced property, without planning permission.

House Extension Visualisation Questions