“Architect drawings” is the phrase most homeowners use for the scaled plans that a council, a builder and a building inspector all need to see before an extension or loft conversion can start. It isn’t one drawing. It’s a set – floor plans, elevations, sections, site and location plans, and a separate technical set for building control – each produced at a different stage, for a different reader.
This guide explains what each drawing shows, when you actually need it, and what architect drawings cost in 2026. Arkiplan has worked this way for 18 years, with more than 2,000 homes granted permission and a 94% planning and LDC approval rate, working remotely with homeowners across England and Wales.
Architectural plans vs architect drawings – is there a difference?
No. “Architectural plans”, “architect drawings” and “architectural drawings” all describe the same deliverable: the scaled set of floor plans, elevations, sections and site plans your council and your builder work from. Use whichever phrase you like – what matters is that the set is accurate, complete and drawn to scale.
Existing and proposed floor plans
Floor plans are the drawings people picture first: a view looking down on each level of the house with the walls, doors, windows, stairs and fixed fittings marked. They always come in pairs. The existing plan records the house exactly as it is today; the proposed plan shows it with the new work built. Your council compares the two to understand precisely what is changing.
Every affected level is drawn – so a rear extension usually means a ground floor plan, and a loft conversion means the first floor and the new loft level. They’re drawn at 1:50 or 1:100 for a householder application.
The existing plan is the one that quietly causes the most trouble. If it’s traced from an estate agent’s sketch, every dimension after it inherits the error, and the mistake surfaces on site when a steel doesn’t fit. We measure from a millimetre-accurate 3D Home Scan of your home, so nothing on the existing plan is guessed. You can see finished projects that started life as these drawings in our portfolio.
Existing and proposed elevations
Elevations are flat, straight-on views of each face of the house – front, rear and both sides – again drawn as existing and as proposed. They show roof lines, window and door positions, ridge and eaves heights, and the materials of the external finishes.
For a planning application, the elevations do most of the work. A planning officer is judging appearance and the effect on neighbours, and that judgement is made almost entirely from the elevations: how high the ridge sits against the neighbouring roof, whether a dormer reads as part of the house, what the rear wall looks like from the garden behind.
This is also where a design decision is cheapest to change. Moving a window on an elevation costs nothing. Moving it after approval means a fresh application.
Sections
A section is a cut-through – imagine slicing the house vertically and looking at the cut face. It shows floor-to-ceiling heights, floor build-ups, roof pitch, and how levels line up between the old house and the new part.
Councils ask for a section where heights or levels matter – a sloping site, a loft conversion where head height is tight, a flat roof sitting close to a boundary. It’s the drawing that proves the finished rooms will actually be usable, not just the right shape on plan. Sections then carry over into the building regulations set, where the same cut is redrawn with construction detail on it.
Site plan and location plan
These two put your project on the map, and they’re the pair most often confused.
- Site location plan – usually 1:1250, showing your property outlined in red within the surrounding streets, so the council can identify the right address.
- Block plan or site plan – usually 1:200 or 1:500, showing your plot in detail: the outline of the house, the extension, boundaries, parking and distances to neighbours.
The block plan is what a planning officer uses to check how close the work sits to a boundary, and whether garden space is being lost. It’s a small drawing that decides big questions.
There’s more on the full validation set in our guide to planning permission drawings.
Building regulations drawings
Planning drawings and building regulations drawings are two different sets, produced for two different approvals, and mixing them up is the single most common misunderstanding we see.
Planning drawings show what the finished project will look like and how it sits in its surroundings. Building regulations drawings are the technical set your builder and building control work from: construction detail, foundations, structure, insulation, drainage, ventilation and fire safety. They’re drawn at a larger scale with notes and detail callouts, and they usually sit alongside a structural engineer’s calculations where a wall is coming out or an opening is being formed.
Many projects need both. Some need only one – a project that falls under permitted development skips the planning application but still needs building regulations approval before anyone builds it.
What architect drawings cost in 2026
Drawing up plans for a home project in the UK usually costs between £1,000 and £5,000+, depending on the size of the job and whether you need planning drawings only or a full set that includes building regulations. Typical ranges:
| Project type | Planning drawings | Full plans (planning + building regs) |
|---|---|---|
| Single-storey extension | £1,000–£2,500 | £2,500–£5,000 |
| Loft conversion | £1,200–£2,500 | £2,500–£4,500 |
| Two-storey extension | £1,500–£3,000 | £4,000–£6,000 |
| New build home | £2,500–£5,000+ | £4,000–£8,000+ |
Those are the drawings only. Budget separately for your council’s planning application fee (typically £300–£700, paid directly to the council) and, if the structure changes, a structural engineer (typically £700–£2,000).
How you’re charged matters as much as the headline number. A traditional architect often charges around 7–15% of your total build cost for a full service, or £50–£100 an hour – so the figure quoted at the start and the figure you pay at the end can be quite different. A fixed price is agreed before any work starts and doesn’t move. Arkiplan prices start from £1,698, with a monthly plan available from £94 a month, and homeowners save £2,284 on average compared with traditional architects.
Our full breakdown is in the guide to how much an architect costs to draw plans.
Do you need a chartered architect to draw them?
No. For a house extension or loft conversion there’s no legal requirement to use a RIBA-chartered architect. Your council assesses the drawings, not the title of the person who produced them, so what matters is that the plans are accurate, complete and drawn to scale.
An experienced architectural designer or technologist can produce everything you need for planning and building regulations, usually for less than a full architectural practice. The expensive outcome isn’t the fee – it’s a refused application, or a set of drawings your builder can’t work from.
How to get architect drawings without a site visit
Getting drawings remotely used to mean sending someone your own tape-measure sketches and hoping. It doesn’t any more. The measuring step is now a 3D Home Scan of your house, which captures the existing building accurately in one visit, and everything after that happens over video and email:
- A 3D Home Scan to measure your home properly
- A design call with your designer to agree the layout
- Existing and proposed floor plans, elevations, and site and location plans
- A revision round to get the design right
- A permitted development check before you commit to a route
- Council submission and chasing until you get a decision
Planning drawings are typically ready in around eight weeks, and councils aim to decide householder applications within eight weeks of validation. You can pay up front or spread the cost across three monthly instalments, with no interest and no credit checks. Every price includes VAT; council fees are paid separately.
See what’s covered for house extension drawings and loft conversion drawings, or compare the three fixed-price packages.
Common questions
Which drawings do I need for a planning application?
A typical householder application needs a site location plan, a block plan, existing and proposed floor plans of every affected level, existing and proposed elevations of each side of the house, and a section where the council asks for one. Hand sketches and rough plans get applications rejected as invalid, which puts you back at the start of the queue.
Do I need planning permission at all?
Many single-storey extensions and loft conversions fall under permitted development, so no planning application is needed – but permitted development rights differ between England and Wales, so the answer depends on where your house is as well as what you’re building. Our guide on whether you need planning permission for an extension covers the limits, written for houses in England with Wales flagged where the rules differ.
If my project is permitted development, do I still need drawings?
Yes, for two reasons. You’ll still need building regulations drawings before the work is built, and we’d recommend a Lawful Development Certificate – the council formally confirms the work is lawful, which protects you when you come to sell. A certificate application needs the same scaled drawings a planning application would.
How accurate do the existing drawings have to be?
Accurate enough that the proposed drawings built from them are right. That’s the reason we scan rather than sketch: every proposed dimension, every steel, every window opening is derived from the existing drawing, so an error there travels all the way to site.