An Architect’s Dream: Customisable Architectural Designs at Your Fingertips.
Why Wait?
30 House Types - each comes with a wide variety of already designed:
Back Extensions
Side Extensions
Wrap Around Extensions
Loft Extensions
Porch Extensions
Various styles of extensions to suit whatever need you may have for your project!


















Here at PDE (Pre Designed Extensions), we believe in pushing the boundaries of architectural creativity by providing pre-designed solutions that serve as the perfect foundation for your projects. Our subscription-based service offers architects a time-saving way to access pre designed extensions for Semi-Detached and Terrace properties, all of which can be easily customised to meet the needs of your clients.
For a monthly fee, you’ll gain access to hundreds of extension designs for a large variety of house types, available in both Revit and DWG formats. These files include complete existing and proposed plans, elevations, and 3D views, making them an ideal starting point for any project. Simply request the designs, adjust them as needed with your client, and submit them for planning approval. With no watermarks and full editability, you maintain complete control over the final product.
Our service is designed to fit seamlessly into your workflow, giving you the flexibility to adapt designs and save time, without compromising on quality or creativity. Best of all, your subscription can be cancelled at any time, providing the ultimate in convenience and flexibility.
With a vast catalogue of designs available at a minimal cost, PDE provides an efficient and affordable way for architects to meet deadlines and deliver high-quality results. Whether you’re looking for inspiration or a ready-to-use solution, our platform gives you the freedom to focus on what you do best: designing.
Take a peek inside our Catalogue
Take a closer look at what we offer! Below, you’ll find a preview of one Terrace property and one Semi-Detached property from our extensive design catalogue. Each house style comes with a complete range of extension designs. Explore detailed plans, elevations, and immersive 3D views for every design, giving you the full picture of what's possible.
Terrace
Semi Detached









Why PDE?
With PDE, you can simplify your design process and how you quickly you progress from collecting the properties keys to receiving planning permission
01.
Streamlined Process
Our customisable designs integrate easily into your process, speeding up project turnaround and simplifying planning approvals
02.
Scalability
Save time on RIBA stages 1-3, allowing you to take on more clients and increase project capacity without compromising quality
03.
Instant Access
Gain instant access to a comprehensive library of pre-designed extensions, covering a wide range of house styles
04.
No Commitment
Flexible subscription - cancel anytime with no long-term obligations
05.
Fully Customisable
Modify any design to perfectly suit your project’s unique needs
Getting started is easy
With PDE, you can simplify your design process and how you quickly you progress from collecting the properties keys to receiving planning permission
01.
Choose Your Plan
Select the subscription plan that suits your needs and unlock instant access to hundreds of designs
02.
Subscribe and Access
Subscribe for a flexible, no-commitment service and start exploring our extensive design catalogue
03.
Select Property & Design
Identify your property type -Semi Detached or Terrace, and its type - then choose from a range of pre-designed extensions
04.
Download Drawings
Download the detailed, watermark-free drawings, fully customisable to fit your project’s requirements
05.
Submit For Planning
Submit the designs for planning approval yourself, or let us handle the submission for you
Fixed pricing to suit all
We believe in a fair and transparent pricing model - always know what you'll pay. No hidden costs. One flat fee
Bronze Architect Plan
100£Every monthValid for 12 months- Access to Existing Catalogue
- 1 Download Per Month
- Existing Drawings
- DWG Files
Silver Architect Plan
200£Every monthValid for 12 months- Access to Entire Catalogue
- 2 Downloads Per Month
- Existing & Proposed Drawings
- DWG & Revit Files
- Request New Designs For Existing House Types
Gold Architect Plan
300£Every monthValid for 12 months- Access to Entire Catalogue
- 5 Downloads Per Month
- Existing & Proposed Drawings
- DWG & Revit Files
- Limited Revisions
- Request New House Types & Designs
- 10% Discount on Additional Services
It makes sense
We're everything you need on your journey to success as an Architect
PDE
In House
Large Catalogue Of Designs
Requests & Revisions
Low Cost Scalability
Customisable Design
Flexible Cancellation
Reliable & Consistent
Fixed Price & Affordability
Digital Accessibility & Instant Access
Revit & DWG File Access
Visualise Various Designs of the Property
Fast Design Turnaround
Easily Meet All Project Demands
Additional Services
We offer flexible add-ons to support your unique project needs. No surprises. Just straightforward options to enhance your plans.
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Why should you pick PDE to design your project?There are three key reasons: Transparency: We prioritise transparency in our service. Before making a purchase, you will have a clear understanding of what you will receive, as you can view all drawings beforehand and the associated costs for them. This means you can proceed with confidence, free from concerns about unexpected invoices or delays. Efficiency: Our ability to deliver high-quality drawings within 24 to 72 hours sets us apart. This efficiency enables you to initiate the process of applying for planning permission or a permitted development certificate much sooner than if you were to choose anyone else. Time equates to money, and the longer a project drags on, the greater the financial impact. While you cannot control the duration of the council's decision-making process, you can control how quickly you initiate your application. With our service, you can obtain the keys to a property on a Monday and submit an application to the council by Tuesday—an unprecedented level of speed in the industry. Cost-Effectiveness: Our pricing structure is significantly more affordable than what you would typically pay an architect, who typically charges around 7% of your construction cost. For example, if your project budget is £70,000, an architect's fee would amount to £4,900, which is significantly more than what we charge, even for our full packages with all additional extras.
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How does PDE know the dimensions of your property?We do not provide measurement services as part of our offerings. For planning there are only a few dimensions required. For all the height needs to be stated and, If you are having a back extension, how far from the rear external wall it extends ie. 4m. If you are having a side extension, how wide it is from the side external wall ie. 2m. If you are having a wrap around extension, how far from the rear external wall it extends, and how wide it is from the side external wall. If you are having a loft extension, how wide it is ie. 3m and how close it is to the edges of the roof ie. 200mm Dimensions of your existing property are not relevant and no dimensions are shown on the submitted drawings but those mentioned above.
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How does PDE consistently achieve and maintain impressive project timelines without compromising quality?Our ability to deliver on tight schedules while upholding quality standards is rooted in our extensive catalogue of pre-designed architectural drawings, specifically tailored for various Terraced and Semi Detached houses in the UK, available in an array of style options. Within this collection, you will find an extensive selection of rear, side, wrap-around, and loft extensions, with some also offering porch extension options. Leveraging the prevalence of similar or nearly identical housing designs across the UK, we can efficiently repurpose and adapt existing drawings, swiftly accommodating your specific requirements, however if you can’t find a match for your property, please reach out. Our approach involves a meticulous examination of every detail, resulting in various styles suited to everyone's taste that are also functional, and fully compliant plans that adhere to all relevant regulations. However, given the unique regulatory nuances of different local councils, occasional minor adjustments may be necessary in the later stages of the process.
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What are the next steps upon receiving the drawings?After you have received the drawings, the following steps are typically undertaken: Planning Permission or Permitted Development Certificate: Depending on the scope of your project, you will need to apply online for planning permission or a permitted development certificate. We offer a service to assist with these applications for a fee of £250 per application, in addition to the application fees themselves. Alternatively, you have the option to submit the applications independently. It's worth noting that in some cases, it may be advisable to submit separate applications for various aspects of the project (e.g., one for the back extension and another for the side extension). This approach can help mitigate potential delays if issues arise with one of the applications, allowing you to commence work on one aspect while awaiting approval for others. Additionally, you have a three-year window from the date of approval to commence construction. Therefore, submitting separate applications can provide flexibility if you are unable to undertake all the work at once within that timeframe. Engaging a Builder and Structural Engineer: Once your drawings are approved, and you have obtained the necessary permissions to proceed with your project, the next steps involve hiring a builder and a structural engineer. Please note that our involvement extends only to the planning stage, and our drawings are intended for planning purposes, not construction. A structural engineer or another architect will provide the builder with detailed construction specifications, and they will need to take their own measurements for precise calculations. DWG Files and Revit Model: We offer the option to purchase the DWG files and the Revit model of the project at an additional cost. These files can expedite and economize the transition to the construction phase. However, it is essential to emphasize that these files are intended for planning purposes and must be carefully reviewed for any construction-related issues." Please note that the information provided here is a general guideline, and specific requirements may vary based on your unique project and local regulations.
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Is consultation available to discuss design and project goals?Certainly, we highly recommend scheduling an online consultation before making a purchase. This consultation provides an opportunity for you to address any inquiries and share your ideas, ensuring a clear understanding of your project's objectives.