Two-storey extension plans and drawings in Berkshire

Berkshire at a glance

Nation: England
Price region: South East England
Postcode areas: GU, RG, SL
Towns covered: 14 listed below, plus surrounding villages
Site visits: Free, no obligation

What a set of extension plans involves

Two-storey extension plans involve a measured survey of your house, design options, and a set of scaled drawings showing the existing and proposed floor plans, elevations, a site plan and a location plan. These are the drawings needed for a planning application or lawful development certificate. Building regulations drawings with construction details follow as a separate, more technical set.

Berkshire towns we list: Reading (RG1), Slough (SL1), Bracknell (RG12), Maidenhead (SL6), Wokingham (RG40) and Newbury (RG14). Every other address in Berkshire is covered as well.

Fees

Planning drawings (survey and design) are a guide of £2,000–£3,500 and building regulations drawings and specification £1,500–£4,000, with your design stage priced in writing before it starts.

Rules in England

In England, the plans support either a householder application, costing £548 (or £575 for applications made from 8 December 2026), or a lawful development certificate for permitted development, costing £274 (about £288 for applications from 8 December 2026). They must show the extension's relationship to the original house, the boundaries and neighbours, because two-storey rear permitted development depends on the 3 m and 7 m limits.

Approval in England: Householder planning application: £548 (or £575 for applications made from 8 December 2026). Lawful development certificate: £274 (about £288 for applications from 8 December 2026). Councils should decide householder applications within 8 weeks of validation.

Building regulations: Building regulations approval (full plans recommended) from the council or a registered building control approver, with a completion certificate at the end.

The Party Wall etc. Act 1996 applies, so notices may be needed for work on or near a shared wall or boundary.

Getting the design right

Compare options early

Sketching two or three layouts, such as rear, side or part two-storey, is the cheapest point to make big decisions. Each option comes with a guide cost and a view on the approval route, so you choose with the full picture rather than discovering limits later.

Drawings that can be built

Drawings that ignore steel sizes, floor depths or drain runs often need redesigning once a builder prices them. We coordinate the design with the structural engineer and our build teams, so what is approved is practical to construct.

How we work in Berkshire

Free site visit
We visit your home in Berkshire, look at the structure, access and boundaries, and talk through what you want the new rooms to do.
Drawings and permission
Our designers produce plans and elevations, then we take care of planning or permitted development checks with the council covering Berkshire.
Technical design
We prepare the building regulations drawings, structural calculations and specification so the build price can be fixed.
Finish and certify
Second fix, plastering and making good, then building control's final inspection and the completion paperwork.

Towns we cover in Berkshire

Two-storey extension plans and drawings in Berkshire: questions

Can I use plans from a previous owner's planning permission?

Sometimes. If the permission is still valid, usually within three years of the decision in England, you can build to it. The drawings may still need updating for building regulations, and the design may not suit your needs. We check old plans and permissions at the free site visit.

Do I own the plans once they are drawn?

You receive copies of the drawings to use for your project, including your planning application and building regulations approval. Copyright in drawings normally stays with whoever prepares them unless agreed otherwise. Your written design stage price sets out how the drawings can be used.

Do the plans include structural calculations?

Not at planning stage. Structural calculations and beam design are prepared by a structural engineer once the design is agreed, and they form part of the building regulations package. We coordinate the engineer's work with the drawings so steel sizes and floor depths match.

Neighbouring areas

All extension services in Berkshire · About two-storey extension plans and drawings