Full Plans vs Building Notice in England: 48 Hours or Plan Checks
Compare full plans and building notice for an England rear extension. Learn how each route affects checks, inspections, certificates, and delay risk.
Full Plans vs Building Notice in England: 48 Hours or Plan Checks
For complex or structural work, such as a rear extension with steel beams, full plans is usually the safer route, because the design is checked before you build. For small, straightforward jobs, a building notice lets you start after 48 hours. Either way, you finish with a completion certificate once inspections are satisfactory.
TL;DR:
- A full plans application requires drawings and structural calculations before work starts; councils aim to decide within five weeks, and approval notices last three years.
- A building notice skips advance plan checks, but work over drains or subject to fire safety rules may require full plans.
- Council fees vary, and total charges can be similar across routes; full plans often involve upfront design costs, while inspection fees may arrive later.
- A building notice can expose problems during construction, so use a builder who understands regulations and arrange inspections before work is covered.
- Keep the completion certificate for a sale or lender request; councils may retain building control records for up to 15 years.
Table of Contents
- What does a full plans application involve?
- How does a building notice work?
- Which route should you choose? A quick checklist
- How do timelines and fees compare?
- What happens at inspections, and why does the completion certificate matter?
- What should you do next for a rear extension?
- Why we handle building control for you
- How we take you from quote to completion certificate
- FAQ
- Sources
What does a full plans application involve?
Full plans is the pre-site approval route. You deposit detailed drawings, a specification and, where the work is structural, calculations with the council before any work begins, as Planning Portal guidance on full plans explains. A location plan usually goes in with them. Our guide to structural calculations for extensions shows what that paperwork covers.
Building control then checks the design against the Building Regulations. Councils aim to decide within about five weeks, and an Approval Notice is normally valid for three years. If the plans fall short, you get a request for changes and resubmit them.
Most homeowners ask an architect or designer to prepare the drawings. Our guide to extension planning drawings covers what to expect.
The benefits are practical:
- You find design problems on paper, not on site.
- Your builder prices and builds from the same approved drawings.
- Approved plans give a clear technical record, which can prevent disputes about methods and quality.
- Lenders and buyers tend to be reassured by a pre-approved design.
Pro Tip: Send your builder the approved plans before they finalise their price, so any change they want is raised before work starts.
How does a building notice work?
A building notice is the simpler, faster route for minor or straightforward domestic work. There is no plan check beforehand. Compliance is verified by inspections as the work progresses.
You submit very little:
- The application form
- A site location plan, at 1:1250 scale where needed
- The fee
You can start 48 hours after submitting the application. Inspectors then check each stage on site. Some councils note that further drawings and calculations may be requested later if the project is complex or sits near sewers or private roads.
There are also firm limits. Under the Building Regulations 2010, some work needs full plans, including building over drains and work subject to fire safety regulation. If your extension crosses a public sewer or sits next to a private road, check with building control first.
The main risk is timing. Problems may only surface during the build, and Homebuilding points out that a non-compliance found by the inspector can mean costly alterations. That makes a competent, regulations-aware builder essential on this route.
Which route should you choose? A quick checklist
Councils such as Manchester advise full plans when you are unsure the work will comply, because it gives the most thorough protection. Work through these questions:
- Does the extension involve structural work, such as removing a wall or adding steel beams?
- Will you build over or near a public sewer or drain?
- Does the site sit beside a private road?
- Will a lender or buyer want evidence the design was approved in advance?
- Do you want your builder to price from approved drawings?
- Can you afford remedial work if an inspector finds a problem?
- Is a quick start more important to you than certainty?
- Is your builder experienced with the Building Regulations?
Mostly “yes” to the first six points to full plans. Mostly “yes” to the last two, on a small simple job, points to a building notice.
The trade-off is plain: full plans costs you time and design fees up front, while a building notice saves time but leaves you exposed to remedial costs later.
Pro Tip: If you are in any doubt, ring your local building control team before you decide. A quick call is cheaper than rebuilding a wall.
How do timelines and fees compare?
Timing and payment are where the routes differ most:
- Building notice: you can start 48 hours after submitting the application, and fees are normally paid when you submit.
- Full plans: allow roughly five weeks for the plan check, which Dover District Council puts at three to five weeks for more complex projects. Statutory time limits can be extended by agreement, and inspection fees are often invoiced later.
- Total cost: some councils note the total can be similar between routes, but charges vary, so check your own council’s scale of fees.
- Your build programme: book your builder around the approval date. A lender releasing funds in stages may also want to see an approval or inspection record before each drawdown.
What happens at inspections, and why does the completion certificate matter?
Inspectors typically visit at these stages of an extension:
- Foundations, before concrete is poured
- Oversite and damp proof course
- Drainage, before it is covered
- First fix, before walls and ceilings hide the work
- Final inspection
Ask your builder to request each visit in good time, because work covered up too early may need to be opened again. If an inspector finds a problem, the builder must put it right and provide any further information the council asks for.
Once everything is satisfactory, the council issues a completion certificate. Treat it as the formal record that the work complies. Keep it safe: you will need it when you sell or when a lender asks. Councils commonly retain records for up to 15 years, and they may charge for duplicates. Our guide to getting a completion certificate walks through the process.
Councils commonly keep building control records, including completion certificates, for up to 15 years, so your own copy is still the safest one to hold.
What should you do next for a rear extension?
Here is a sensible order of play:
- Decide on your preferred route, using the checklist above.
- Confirm any constraints, such as sewers or private roads, with your local authority or an approved inspector.
- Get structural calculations done where beams or wall removals are involved.
- Build plan-checking time into your programme if you choose full plans.
- Bring in a designer for full plans, or a competent builder with a clear inspection schedule for a building notice.
- Budget for design fees, inspection charges and a contingency in case an inspector requires remedial work.
- File your approvals and completion certificate where you can find them later.
Our guide to rear extension design helps with the early decisions. If outdoor works are part of your plan, this outdoor renovation checklist is a useful companion.
Why we handle building control for you
Approvals are where extension projects most often stall, so we manage them ourselves. We prepare the technical submissions, run the structural checks in-house and liaise with building control until the completion certificate is issued. You deal with one team, and our live 3D modelling lets you see the design before anything is submitted. If you want guidance on your own project, get in touch and we will talk it through.
— Esskay
How we take you from quote to completion certificate
We offer a managed, fixed-price route for single-storey rear extensions, with VAT included, and it covers the approvals you have just read about.
- Instant online quote and live 3D design
- Technical drawings and structural calculations prepared by our in-house team
- Planning and building control submissions handled for you
- Project management and construction, backed by a workmanship warranty
Start with our instant quote tool, see how it works, or read about our single-storey rear extension service. Our booking fee is £499, paid once.
FAQ
What is a full plans building control application?
It is an application where detailed drawings, a specification and, where needed, calculations are checked by building control before work starts. You receive an Approval Notice once the plans comply, and inspections follow during the build.
Do I need a building notice?
Not necessarily. A building notice suits small, straightforward domestic work and lets you start after 48 hours. Councils tend to advise full plans when you are unsure the work will comply, or when it is structural or near sewers.
Can I switch from a building notice to full plans?
Whether you can switch depends on your council’s rules and how far work has progressed, so ask your local building control team before you decide. It is far easier to choose the right route at the start.
What are the current building regulations in England?
The legal framework is the Building Regulations 2010. The technical standards sit in the Approved Documents on gov.uk, and gov.uk’s approval guidance sets out the application routes.
Sources
- Extensions – a homeowner’s guide to extending your living space
- Choose which application to use | Check what work you’re doing | Manchester City Council