House Extension Planning Drawings
House Extension
Drawings.
From £500 + VAT · drawings only
Clear, property-specific drawings for house extensions across the UK.
The short answer
What Architectural Drawings Does Your Extension Need?
House extension drawings are not simply a council requirement. They establish what exists, what you want to change and how the proposal relates to the original house, neighbouring properties and its surroundings.
Estate-agent plans are useful for marketing a property, but they are not normally suitable for design or planning work. They may not be accurately scaled or show the roof, levels, boundaries and neighbouring features that can influence an extension proposal.
- We begin by reviewing your property and what you want to achieve. A straightforward rear extension may only require a conventional planning drawing package. A more constrained proposal could require additional levels, neighbouring windows, local planning precedent or supporting assessments to be considered before the design is finalised.
- Depending on the property and proposal, the appropriate route may be a Lawful Development Certificate, Householder Planning Application, Full Planning Application or Listed Building Consent.
- At AC Design Solution, we consider the existing building, roof form, boundaries, neighbouring properties, local character and planning context before preparing the drawings. The result is a package developed for the actual property—not a standard extension placed onto a generic floor plan.
From approval to construction
Home Extension Plans Made Clear
We survey and draw the existing house before developing the proposed plans, elevations and sections needed to communicate the design clearly.
The example shown is from our approved project at 46 Winston Road in Hackney. The proposal combined a mansard roof extension, alterations above the rear outrigger and a single-storey side and rear extension.
Explore the drawing package
Prepared properly
MCIAT-qualified professionals
Your package is developed by people trained to turn design intent into technical information.
A clear programme
Typically 5–10 working days
Once the required information is available, we confirm the programme and keep the package moving.
Fewer gaps on site
One coordinated package
Architecture, structure and building services are considered together—not left for your builder to untangle.
Your drawing package
What’s Included in Your Plans?
A property-specific drawing package for planning your house extension. We record the existing house, develop the proposal and prepare the plans
Measured Site Survey
We visit the property to record key dimensions, photographs and site information, creating an accurate base for the extension drawings.
Existing Plans & Elevations
Floor plans and elevations show the house as it stands, including the areas affected by the proposed extension.
Design Development
We test the layout, scale, roof form and relationship with the existing house before developing the preferred proposal.
Proposed Floor Plans
Clear plans show the new layout, room relationships, openings and how the extension connects with the existing home.
Elevations & Sections
Proposed elevations and sections explain the external appearance, heights, levels, roof form and key spatial relationships.
Application-Ready Drawing Set
A coordinated PDF drawing package prepared for the appropriate planning route, ready for you or your appointed agent to submit.
What it costs
How Much Do House Extension Plans Cost?
These prices cover the drawing package only and are subject to VAT. Planning application fees, council charges and any separately required specialist surveys or reports are not included.
Planning drawing packages
For straightforward house extensions, drawings for a Lawful Development Certificate or Householder Planning Application start from £500 + VAT.
Complex and heritage projects
Full Planning Application drawings start from £800 + VAT. Listed Building Consent drawings start from £1,500 + VAT, reflecting the additional design and heritage information required.
Lawful Development Certificate
Planning drawings for a house extension that may qualify as permitted development, prepared to clearly demonstrate the proposal to the local authority.
Householder Planning Application
A complete planning drawing set for extensions that require householder planning permission, showing the design in relation to the existing house and its surroundings.
Full Planning Application
Drawings for proposals that need a full planning application, with the additional information and level of detail required for the site and development.
Listed Building Consent
A more detailed drawing package for alterations to a listed property, developed around its architectural character, significance and heritage requirements.
Planning application fees and council charges are paid separately by the client.
We confirm the scope, planning route and fixed quotation before you appoint us.
Real project evidence
A Planning Drawing Package Is Not a Template.
A set of plans can be technically neat and still fail to address the reason a council may object. The value lies in understanding what the drawings need to demonstrate and developing the proposal accordingly.
At 46 Winston Road, an earlier proposal had been refused over its scale, massing and effect on neighbouring daylight. Simply redrawing the same scheme more neatly would not have solved those problems.
Understand the Real Planning Issue
The refusal was read as a design brief. We reviewed the refusal reasons and the planning officer’s comments, but we also challenged their stance not through a lengthy appeal, but by asking targeted questions. In our planning statement, we highlighted similar approved developments in the area. The officer countered that comparable developments needed to be in the “immediate vicinity.”
This was a departure from the usual practice of citing comparables from anywhere on the same street. Fortunately, we had done our research. We knew the house directly opposite had secured planning permission for the exact same development—approved by the very same case officer.
Changing the Design Where It Mattered
The revised design was tested, not merely described. Alongside challenging the council’s inconsistencies, we made targeted changes in response to identified planning concerns, rather than making arbitrary design revisions:
- Reduced Proportions: The revised rear roof extension was reduced in height and depth.
- Chamfered Roof Plane: Introduced to reduce the apparent mass next to the neighbouring property.
- Set-Back Eaves: The new roof was set back from the existing eaves.
Ground-Floor Adjustments: The ground-floor extension was reduced and given a revised roof form.
CLIENT FEEDBACK
Loved by homeowners and builders.Trusted across every detail.
“Excellent service! Very professional and punctual . Competitive price.”
“We used AC Design Solution for planning permission on a single storey extension and loft conversion, plus the building regulation drawings, structural calculations, and party wall surveying. They handled the whole process well and kept us updated throughout, which made things a lot less stressful than we expected. The drawings and structural work were solid, and the party wall side went smoothly too. Would recommend them to anyone needing help with planning and building regs.”
“I had an issue on site that required appointing a Party Wall Surveyor. My architect recommended Zubear from AC Design Solution, who I must say is extremely experienced and kept me updated throughout. We faced a challenging experience with the council and their surveyor, but Zubear overcame the issues, allowing me to get my Party Wall matters sorted out.”
“AC Design Solutions were fantastic in getting the job done promptly and in a professional manner. They also gave us helpful advice which assisted in our decision making with other aspects of the building works. I would highly recommend them.”
“Very supportive and helpful. Very fast response as well! Highly recommend”
Your project
Home Extension Design by Project Type.
Single Storey Extension Plans
A single-storey rear extension can create a larger kitchen, dining area or family space, but its depth and height must be considered in relation to the existing house and neighbouring properties.
We prepare existing and proposed plans, elevations and relevant sections showing the extension as part of the complete property. Explore single-storey extensions.
Side and Side-Return Extension Plans
Side-return extensions can make effective use of narrow space beside a rear outrigger. The roof junction, boundary position, daylight and relationship with adjoining windows need to be resolved carefully.
The drawings must explain how the side and rear elements connect rather than treating them as two unrelated additions..
Wraparound Extension Plans
A wraparound extension combines side and rear development to create a larger connected footprint.
Because the extension occupies more of the plot, its massing, roof form and relationship with the original house require more careful design than a simple rear addition.
Double Storey Extension Plans
Double-storey extensions have a greater effect on the external appearance of the house and the amenity of adjoining properties.
The width, roof design, upper-floor windows, separation from boundaries and balance of the original elevation all become important planning considerations. Explore double-storey extensions
House Extensions With Loft Conversions
Some projects combine a ground-floor extension with a loft conversion, mansard or rear roof addition.
Both parts should be designed together so the application reads as one coherent proposal. The 46 Winston Road project is an example of this coordinated approach.
Explore loft-conversion services
Built around real projects
Relevant project evidence.
2-4 Mill Street LU1
View project
54A Church Road, Richmond — Rear and Side Extension
View project
7 New Apartments Hounslow Isleworth Planning Permission
View project
Akenside Road, Hampstead
View projectPreparing Extension Plans for Your Local Council
Lawful Development Certificate
Some extensions can be carried out under permitted-development rights without applying for conventional planning permission.
A proposed Lawful Development Certificate gives formal confirmation from the local planning authority that the proposal would be lawful for planning purposes.
Permitted-development rights can be restricted or removed through planning conditions or an Article 4 Direction. They also do not apply to every type of residential property. The property must be checked before relying on them.
A Lawful Development Certificate confirms the planning position only. It does not remove the need to comply with Building Regulations or any other applicable consent.
Householder Planning Application
This is the usual planning route for many extensions and alterations to a single dwellinghouse that do not fall within permitted-development rights.
The council normally considers the scale and appearance of the extension, its relationship with the existing property, local character and the effect on neighbouring amenity.
Full Planning Application
A full application may be required where the proposal or property does not fall within the householder application route. This can include works to flats, mixed-use properties or proposals forming part of wider development.
Listed Building Consent
Listed Building Consent may be required for work that affects the special architectural or historic character of a listed building.
The protection can apply to the interior as well as the exterior, and planning permission may also be required. A listed-building application may need more detailed existing information, a heritage statement, a schedule of works and drawings identifying affected historic fabric.
Planning Drawings Are Not Construction Drawings
The distinction matters because each set answers a different question.
Planning Drawings
Planning drawings explain what the extension will look like, where it will sit and how it relates to the existing property and surrounding area.
They focus on design, scale, appearance and planning impact.
Building-Regulation Drawings
Building-regulation drawings explain how the extension will be constructed and how the work will satisfy applicable technical requirements.
They can include construction build-ups, insulation, fire safety, ventilation, drainage and detailed junctions.
Structural Calculations
Structural calculations may be required where the project introduces beams, removes load-bearing walls, alters the roof or requires new foundations to support significant loads.
They should be coordinated with the architectural and building-regulation information.
Party-Wall Matters
An extension close to a shared structure or requiring excavation near a neighbouring building may fall within the Party Wall etc. Act 1996.
Planning permission does not remove party-wall obligations.
Why Use a Chartered Architectural Technologist?
House-extension drawings do not have to be prepared by a registered architect. What matters is that the person producing them understands buildings, design, drawing standards and the planning context in which the proposal will be assessed.
AC Design Solution is led by MCIAT-qualified Chartered Architectural Technologists. Our architectural work is also supported by in-house structural engineering and party-wall experience.
That wider understanding matters because an extension is rarely isolated from the rest of the building. A new layout may require structural openings. A wall position may affect party-wall procedures. A roof form may satisfy a planning objective but introduce a difficult construction junction later.
We keep each professional stage clearly defined while considering how the decisions made during planning may affect the stages that follow.
The service is not valuable because somebody can operate drawing software. It is valuable because the right information is recorded, the right questions are asked and the proposal is developed around the real property before the drawings are issued.
Common questions
Before you begin.
Do All House Extensions Require Planning Permission?
No. Some extensions may qualify as permitted development, while others require a Householder Planning Application, Full Planning Application or another consent.
The route depends on the property, location, planning history and proposed design.
Do I Need Drawings for Permitted Development?
Drawings are still needed to define the proposal and demonstrate that it falls within the relevant permitted-development limitations and conditions.
Many homeowners apply for a Lawful Development Certificate so the council formally confirms the planning position.
Is a Measured Site Survey Included?
A measured site survey is included where stated in your agreed package. It provides the base information required to prepare accurate existing drawings.
We do not use estate-agent plans as a substitute for verified survey information.
What Drawings Will I Receive?
A typical package can include existing and proposed floor plans, elevations, roof plans, relevant sections and site information.
The exact contents are confirmed after reviewing the property and planning route.
How Long Do House Extension Drawings Take?
The programme depends on the size and complexity of the property, the proposed design and whether additional information is required.
We provide a realistic drawing programme before work begins rather than promising the same turnaround for every project.
Do Your Prices Include the Planning Application?
No. The prices on this page cover preparation of the agreed drawing package only.
Application preparation and submission, council charges, specialist reports and post-submission work are separate unless your quotation expressly includes them.
Can Planning Approval Be Guaranteed?
No responsible professional can guarantee the decision of a local planning authority.
We assess the property, develop the proposal around relevant planning considerations and prepare a clear supporting drawing package. The final decision remains with the authority.
Can My Builder Construct the Extension From Planning Drawings?
Planning drawings are not normally detailed enough for construction.
Most extensions need a separate building-regulation package. Structural calculations may also be required before building work begins.
What Additional Reports Could Be Required?
Depending on the property and proposal, supporting information might include a Design and Access Statement, planning statement, heritage assessment, daylight and sunlight assessment, tree information, flood information or another specialist report.
These are not automatically required for every extension.
Can You Help Following a Planning Refusal?
Yes. A refusal should be reviewed before the proposal is redrawn.
The decision notice, officer report, relevant planning policies and design need to be considered together. The Winston Road approval demonstrates why a targeted design response can be more effective than resubmitting a similar proposal.
Do the Same Planning Rules Apply Across the UK?
No. Planning legislation, permitted-development rights, terminology and application procedures vary between England, Wales, Scotland and Northern Ireland.
We confirm the requirements that apply to the location of your property.
Tell us what you are planning
Let’s talk about your Extension.
Send us the property address, photographs, any existing plans and a short explanation of what you want to achieve.
Continue your research
House Extension Advice and Guidance
Previous Owner Built Without Permission: What Should the New Homeowner Do?
Discovering building work that does not appear to have the right approvals can turn what looked like a straightforward renovation into a much more complicated project.
Renovating a Home in a Camden Conservation Area
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Can You Extend the Front of Your House?
Front extensions usually need planning permission. Learn the rules, permitted development limits, building regulations, costs, and design considerations before you build.