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House Extension Drawings

Planning a home extension? You need the right drawings before anything else happens. Whether you’re adding a rear extension, going up a storey, or creating open-plan living space, house extension drawings are what make your project legal, buildable, and approved. At AC Design Solution, we’re CIAT Chartered Architectural Technologists who’ve delivered over 10,000 UK projects. We handle your architectural services from design through to building control — at a fixed price, entirely online.

Building regulation drawings - showing block and beam floor make up
2,000+
Building Regulation Drawings
All time
2012
Established
Trusted since
MCIAT
Qualified
Professionally accredited
FREE
BC Submission Included
No hidden costs

How much does an architect actually charge?

Using a traditional architect for drawings for your house extension typically costs between 8% and 15% of the build cost. On a £60,000 extension, that's £4,800 to £9,000 in design fees before a planning application or building control submission — and that's before unexpected costs from amendments or resubmissions.

You shouldn't pay more in design fees than you do in floorboards.

At AC Design Solution, we work on fixed pricing with no hidden costs. Our easy and online home extension service removes the high costs associated with traditional practices. Pre-checked drawings reduce the risk of unexpected costs before submission.

Our architectural designers handle everything remotely — floorplans, elevations, planning drawings, and full building regulation drawings for extensions — all delivered online. Once approved, your tradesperson can build directly from our drawings with confidence.

Cost comparison: traditional architect vs AC Design

A £60,000 extension
Fig 01
Traditional
8–15%
of build cost in design fees
AC Design
£600+
flat fee, plans & elevations included
Line itemCost
Traditional architect (low)£4,800
Traditional architect (high)£9,000
AC Design fixed fee£600–£1,500
Saving on a £60k buildup to £8,400
CALL US TODAY ON 0208 152 4006

5 Star Client Reviews

Don’t just take our word for it – hear directly from satisfied clients about their experience working with us. These real stories demonstrate why businesses trust us to deliver outstanding results every time

Rahul Kukar
I appointed AC Design Solutions for a challenging new build project - demolishing an existing house and replacing it with 7 new flats in Isleworth. The team provided a comprehensive service including architectural design, structural engineering ...
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Rahul Kukar
I appointed AC Design Solutions for a challenging new build project - demolishing an existing house and replacing it with 7 new flats in Isleworth. The team provided a comprehensive service including architectural design, structural engineering calculations, building regulations drawings, and preparation of all the technical reports required for planning (drainage, energy, daylight/sunlight, arboricultural, etc.). The project was taken to Hounslow Planning Committee and we achieved unanimous approval on the first attempt. AC Design Solutions were very responsive throughout, handled all the pre-application consultations, and prepared a strong case that addressed all the planning concerns. Their knowledge of local planning policies and building regulations was excellent, and they coordinated all the specialist consultants we needed. The building regulations drawings were detailed and compliant, ready for submission. I would highly recommend AC Design Solutions for residential development projects in West London. Really pleased to have these guys on my team - they are absolutely on the ball, and I look forward to doing many more projects with them in expansion of my portfolio.
Rahul Kukar
Rahul Kukar
Will Sharpey
GF and Loft Extension PW, Archy, Structures Party Wall, Architecture, Structural and Civil Engineer services. Ground floor extension and loft conversion / extension. All executed in a timely manner at a very reasonable rate.
Will Sharpey
GF and Loft Extension PW, Archy, Structures Party Wall, Architecture, Structural and Civil Engineer services. Ground floor extension and loft conversion / extension. All executed in a timely manner at a very reasonable rate.
Will Sharpey
Will Sharpey
ADAM LORD
If you are looking for honest, straight talking professional advice. Look no further. Extremely efficient and very good at following up on their work. Thanka again and I look forward to working with you again ...
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ADAM LORD
If you are looking for honest, straight talking professional advice. Look no further. Extremely efficient and very good at following up on their work. Thanka again and I look forward to working with you again in the future.
ADAM LORD
ADAM LORD
Gita Kocareva
I apply online and straight away had response. All questions answered . Fast reply to any e mails. All paperwork ready within 3 working days. Thank you.
Gita Kocareva
I apply online and straight away had response. All questions answered . Fast reply to any e mails. All paperwork ready within 3 working days. Thank you.
Gita Kocareva
Gita Kocareva
Laura Saperstein
AC Design worked quickly and professionally on my job seeking a regularisation certificate from building control. I can recommend them
Laura Saperstein
AC Design worked quickly and professionally on my job seeking a regularisation certificate from building control. I can recommend them
Laura Saperstein
Laura Saperstein
Christopher Thompson Royds
Super efficient, good communication, and very quick turn around of the structural report which Buildings Control approved. Really happy and would use again. Thanks Guys
Christopher Thompson Royds
Super efficient, good communication, and very quick turn around of the structural report which Buildings Control approved. Really happy and would use again. Thanks Guys
Christopher Thompson Royds
Christopher Thompson Royds
Ali X
Brilliant staff, always friendly and always available, we’ve done two very successful projects with them and looking forward to working with them again.
Ali X
Brilliant staff, always friendly and always available, we’ve done two very successful projects with them and looking forward to working with them again.
Ali X
Ali X
Gang Hu
We had a great experience with AC Design Solutions. They responded to our request for structural drawings and calculations swiftly and the whole work was delivered very quickly with excellent quality. Highly recommended.
Gang Hu
We had a great experience with AC Design Solutions. They responded to our request for structural drawings and calculations swiftly and the whole work was delivered very quickly with excellent quality. Highly recommended.
Gang Hu
Gang Hu
Ali
Had a great experience with AC Design, the customer service was great and they responded to our questions promptly. Turnaround for designs were quick too. I especially appreciated having a call with the engineer as ...
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Ali
Had a great experience with AC Design, the customer service was great and they responded to our questions promptly. Turnaround for designs were quick too. I especially appreciated having a call with the engineer as it helped us understand why the designs were constructed in a certain way. Highly recommend this company if you require structural drawings done
Ali
Ali
Godwin Temisa
With excellent communication and quick turnaround, they designed a floor plan that will allow more light to come to the bedrooms. I am impressed by how they sectioned the rooms and even managed to create ...
Read More
Godwin Temisa
With excellent communication and quick turnaround, they designed a floor plan that will allow more light to come to the bedrooms. I am impressed by how they sectioned the rooms and even managed to create a large study. Based on my experience, I would like to recommend their service.
Godwin Temisa
Godwin Temisa
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Still Have Questions About Your House Extension Drawings

Getting house extension drawings right from the start saves time and money. Whether you need planning drawings, building regulation drawings, or both, our CIAT Chartered team will tell you exactly what your project needs.

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Types of Home Extension Plans and Design

The types of house extension we draw for include single storey extensions, double storey extensions, side return extensions, and wrap-around extensions. Each type has different planning and building regulation requirements, and your drawings need to reflect that from the outset.

Most homeowners need two sets of drawings. Planning drawings go to your local planning authority when you need planning permission. Building regulation drawings for extensions go to building control and cover the technical construction detail your builder works from. Some projects fall under permitted development, meaning you don’t require planning permission at all — applying for a lawful development certificate confirms this in writing instead. The same drawing process applies whether you’re building an extension or combining it with a loft conversion.

If your extension sits close to a shared boundary, you may also need to serve a party wall notice before building work begins. We flag this early so it doesn’t delay your project.

Building control section drawing for a multi-storey residential building at Kings Road, Chelsea prepared by AC Design Solution

Our Recently completed House extension drawings

01
The honest comparison

Why pay more,
and get less?

Traditional architect services charge for site visits, travel time, and studio overheads. Our architectural services work differently. We operate as online architectural designers — CIAT Chartered professionals, full home extension design from concept through to approval, and pre-checked drawings that remove the risk of costly amendments. We also offer 3D home scanning for complex projects where precision matters.

Traditional Architect

What you're paying for

  • × Site visits, travel time, hourly rates
  • × Studio overheads built into every quote
  • × 8–15% of the build cost in fees
  • × Costly amendments after submission
  • × Long lead times before drawings begin
VS
AC Design Solution

What you actually get

  • CIAT Chartered architectural designers
  • Full home extension design — concept to approval
  • Pre-checked drawings before submission
  • Fixed price from £600 — no hidden costs
  • 3D home scanning for complex projects
02 / Technical drawings

Architectural technologist drawings for extensions

Architectural technologists specialise in the technical side of construction — exactly what extension design and architectural design requires.

Our team produces design drawings and architectural plans that satisfy both the local planning authority and building control, covering floorplans, elevations, and full construction detail for every architectural building project we take on.

Every set of extension building regulations drawings we produce must comply with building regulations under the current approved documents. We coordinate with structural engineers where load-bearing alterations are involved, and work directly with your approved inspector or local authority building control officer throughout. For projects where a full plans application isn't necessary, we advise whether a building notice suits your project instead.

The steps

Plan Your Extension in 4 Easy Steps

Step 1
3
Step 1

Send Your Details

Submit your property information, measurements, and what you’re looking to build. Online home extension plans start here — no site visit needed for most projects.

Step 2
3
Step 2

Submission

We submit your planning application, handle applying for a lawful development certificate, or manage the building control submission — whichever the planning process requires.

Step 3
3
Step 3

WE DO THE DRAWINGS

We handle the entire building regulations application process. We work with your local building control officer or approved inspector on your behalf.

Our complete set of building regs drawings means one thing. Your builder can proceed with confidence once approval is granted. We include full drawings and specifications so your contractor has everything needed on site.

Step 4
3
Step 4

Approval and Build

Once approved, your tradesperson builds directly from our technical drawings. We remain available throughout if your approved inspector or building control officer has queries.

ARCHITECTURAL SERVICES & DESIGN

Existing Drawings

Every project starts with an accurate record of your existing property — measured floorplans and elevations of the existing architectural building before any proposed works are drawn.

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FAQ

Why do I need house extension plans and designs?

You need architectural drawings to apply for planning permission or a certificate of lawfulness, and to comply with building regulations. Without approved drawings, building work cannot legally begin.

How long does it take to get house extension plans and drawings?

Most planning and building regulation drawings for extensions are completed within 2 to 3 weeks. Projects requiring structural input may take slightly longer.

How much do extension drawings and plans cost?

We provide fixed-price quotations before any work begins, so there are no unexpected costs. Contact us for a no-obligation quote based on your extension.

Do I need an architect for my house extension plans and drawings?

No. Chartered Architectural Technologists are fully qualified to produce planning and building regulation drawings for house extensions. Our architectural designers handle everything from design drawings through to submission.

When do I submit my house extension plans and drawings to my local council?

Planning drawings are submitted before work starts. Building regulation drawings for extensions go to building control after planning approval. We manage both and guide you through the full planning process.

Is your 3D Home Scan survey accurate?

Yes. Our 3D scanning produces millimetre-accurate measurements, removing the margin for error that comes with manual measuring.

What if I need design changes?

What if I need design changes?

Revisions are included in our fixed-price packages. We work with you until the drawings reflect exactly what you want to build, with no high costs for changes along the way.

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