Planning a home extension is one of the most significant decisions a homeowner can make. It changes how you live in your home, affects its value, and in most cases requires engagement with the planning system. Unsurprisingly, more and more homeowners are turning to online services to navigate the process — looking for professional help without the complexity and cost of a traditional architectural practice.
But what actually exists online? And how do you tell the difference between a service that produces council-ready drawings and one that simply generates something that looks like a plan?
This guide breaks down the types of online services available, what each one is suited for, and what to look for when choosing the right support for your project.
The difference between online tools and online services
Before exploring what's available, it's worth drawing a clear distinction. There are two very different categories of "online help" for home extensions:
Online tools are software applications — Planner 5D, RoomSketcher, HomeByMe — that let you drag and drop rooms, experiment with layouts, and visualise ideas in 3D. They are useful for sketching concepts and sharing rough ideas with family or a builder. They do not produce drawings suitable for planning permission or building regulations approval.
Online services are professionally run architectural design practices that happen to work remotely. They produce the kind of accurate, scaled, compliant drawings that a local planning authority requires. The output is indistinguishable from what a traditional architect produces in person — because the process, skills, and regulatory knowledge behind it are the same.
If your extension needs planning permission or building regulations approval — and most extensions do — you need a professional online service, not a design tool.
What online architectural services offer homeowners
A professional online extension design service typically handles some or all of the following:
Existing and proposed drawings — scaled floor plans and elevations showing your property as it currently stands, alongside detailed drawings of the proposed extension. These are the core documents required for a planning application.
Site location and block plans — OS-based plans showing your property's position within its surroundings, which form part of any planning submission.
Permitted development assessments — many straightforward rear extensions fall within permitted development rights and don't need full planning permission. A good online service will advise on this before you spend money on a full application.
Lawful Development Certificate drawings — where planning permission isn't required, an LDC provides formal written confirmation that your project is lawful. Some homeowners obtain these for peace of mind or when selling.
Building regulations drawings — separate from planning, these detailed technical drawings are required before construction begins and are reviewed by your local building control body or an approved inspector.
At Architectural.Services, we provide all of these services remotely, working with homeowners across the UK. You don't need to arrange a site visit — we work from the information you provide, supplemented by OS mapping and satellite data.
Who are the main online extension design services?
The UK market has a growing number of online architectural services competing for the same homeowner audience. They differ in price, process, and the depth of service they provide.
Full-service online practices handle everything from initial design through to planning submission. They combine architectural knowledge with planning expertise and typically offer fixed fees. Services like Architectural.Services and Resi sit in this category. Architectural.Services works entirely remotely and covers the full range of residential planning and building regulations work. Resi operates a hybrid model, visiting your property once for a digital scan before managing everything else online.
Drawing-only services take your measurements and produce plans without contributing design input. They are lower cost but offer less value if you're still working out what your extension should look like or whether it will get approved.
Freelance platforms such as Fiverr feature individual draughtspeople offering planning drawings at budget prices. Quality varies considerably, and there's little accountability if drawings are rejected by the council.
DIY visualisation tools are best treated as a starting point — useful for exploring ideas, but not a substitute for professional drawings.
What to look for in an online extension design service
Choosing the right service matters. A poorly drawn application can result in a planning refusal, delays, or costly revisions. Here's what to consider:
Relevant experience with residential planning. Extension design is a specific discipline. Look for a service that works primarily with homeowners on residential projects — not one that does extensions alongside commercial fit-outs and masterplanning.
Transparent, fixed fees. Online services should be able to give you a clear price upfront. If a service hedges around costs or bills by the hour, that's worth questioning.
Understanding of local planning policy. Planning decisions are made at local authority level, and what's acceptable in one borough may be refused in another. A good service will factor in local policy and character when advising on your design.
Clear communication throughout. You should know who is working on your drawings, how revisions are handled, and what the process looks like from instruction to submission.
Drawings prepared to validation standards. Councils will reject applications that don't meet their submission requirements. Professional drawings should already account for scale, title blocks, north points, and the drawing types the authority requires.
At Architectural.Services, every set of drawings is prepared with council submission requirements in mind. We also provide guidance throughout the process, so you're never left wondering what happens next. Get a free quote for your extension project here.
Does your extension need planning permission?
This is often the first question homeowners ask. The answer depends on the size, location, and nature of your extension.
Many single-storey rear extensions can be built under permitted development rights without a full planning application — but the rules are specific and depend on factors including property type, location within conservation areas or Article 4 directions, and the cumulative size of any previous extensions.
Two-storey extensions, side extensions, and anything involving significant changes to the roof or front of the property typically require planning permission.
Before committing to any service, it's worth getting a clear steer on whether your project needs permission or whether a Lawful Development Certificate would suffice. Our planning permission drawings service includes an initial assessment of your permitted development position.
Getting started
If you're planning an extension, the most productive first step is usually a conversation about what you're trying to achieve and whether the project needs planning permission. From there, a professional online service can advise on design, prepare the drawings, and guide you through submission.
You don't need to visit an architect's office, commission an expensive full-service project, or navigate the planning system alone. Online architectural services make professional-quality drawings accessible, affordable, and straightforward — wherever you are in the UK.
Request a free quote from Architectural.Services — we'll confirm what drawings your project needs and provide a fixed price with no obligation.