How Long Does Building Regulations Approval Take?

Should I Get Building Regulations Before Getting Builder Quotes?

It can be very useful.

A technical package gives contractors clearer information about:

• foundations;
• walls;
• floor;
• roof;
• insulation;
• beams;
• drainage.

This makes quotations more comparable.

Without technical information, contractors may make different assumptions.

How Long Does a Building Notice Take?

A Building Notice works differently.

There is no equivalent formal approval period because you do not receive formal approval of detailed plans.

Current GOV.UK guidance says you can normally start work:

2 days

after the Building Notice has been submitted.

But this does not mean:

“Building Regulations are approved in two days.”

There is no Full Plans-style formal approval.

Compliance is assessed during the Building Control process.

Is a Building Notice Faster Than Full Plans?

It can allow a faster start.

But it does not automatically produce a faster overall project.

If important design issues are unresolved, delays can occur during construction.

For example:

Builder starts

↓

Building Control asks for structural calculation

↓

Work pauses

↓

Engineer designs beam

↓

Drawing revised

↓

Steel ordered

That may be slower than designing the beam before construction.

When Is Building Notice Appropriate?

GOV.UK describes Building Notice as an option for smaller projects.

It can suit certain straightforward domestic work where the route is legally available.

But procedural simplicity does not eliminate technical complexity.

If your project contains:

• substantial structural work;
• complex fire safety;
• several interacting regulations;

Full Plans can provide more certainty before construction.

How Long Does Building Control Take With a Registered Building Control Approver?

A Registered Building Control Approver, or RBCA, operates through a different procedure from local-authority Full Plans.

The RBCA and the person carrying out the work normally use the initial notice process.

The local authority has an existing statutory period of 5 working days in which it can reject an initial notice where there are grounds to do so.

If it is not rejected within the applicable period, it can be treated as accepted.

That 5-working-day period should not be confused with:

• technical design time;
• Building Control checking;
• construction;
• final certification.

The RBCA still carries out its Building Control function throughout the project.

Does an RBCA Approve My Plans in 5 Days?

No.

The five-working-day period concerns the local authority's treatment of the initial notice.

It is not a five-day technical approval of your project.

The appointed RBCA will have its own:

• plan review;
• queries;
• inspections;
• certification process.

Ask the chosen RBCA for its expected technical-review timescale.

Local Authority vs RBCA Timescales

For ordinary non-higher-risk residential work:

Local Authority Full Plans

Formal Full Plans decision normally:

5 weeks

or:

2 months with consent

Local Authority Building Notice

Work can normally start:

2 days after submission

No formal plan approval.

Registered Building Control Approver

Initial-notice procedure applies.

Local authority rejection period:

5 working days

Technical-review programme:

provider/project dependent.

Does the Five-Week Rule Apply to Every Building Control Provider?

No.

The well-known five-week decision period relates specifically to the Full Plans process.

Do not assume a private RBCA has exactly the same internal technical review programme.

If programme is important, ask:

• when initial notice will be issued;
• when drawings will be reviewed;
• when comments are expected;
• what information is needed before construction.

How Long Does Building Control Take During Construction?

There is no single standard duration.

Building Control follows the construction programme.

If the project takes:

3 months

Building Control inspections may take place across those three months.

If construction takes:

12 months

the Building Control process may remain open for that period.

The Building Control timeline is therefore partly controlled by the building programme.

How Many Building Control Inspections Are There?

There is no universal number.

The Building Control body determines the inspection requirements based on the project.

Possible domestic inspection stages include:

• excavation;
• foundations;
• oversite;
• drainage;
• structural work;
• insulation;
• roof;
• completion.

A small wall removal may require fewer visits than a new house.

Do Inspections Slow Down Construction?

They should be built into the programme.

Problems arise when:

• the contractor does not give sufficient notice;
• work is covered before inspection;
• defects are identified;
• required information is unavailable.

Good coordination can minimise unnecessary disruption.

What If Building Control Cannot Attend Immediately?

The arrangements depend on the Building Control body.

Contractors should communicate inspection requirements in advance rather than waiting until the work is about to be concealed.

For example, do not finish excavating foundations late Friday afternoon and only then ask for an immediate inspection.

What Happens If Work Is Covered Too Early?

Building Control may need evidence to determine whether the concealed construction complies.

It may request:

• photographs;
• certificates;
• test evidence;
• opening-up.

That can delay the project significantly.

How Long Does a Completion Certificate Take?

Current GOV.UK guidance says that under the Full Plans route you will usually receive a completion certificate within 8 weeks of completion, provided the building work complies.

This is an important distinction:

completion of construction

does not necessarily mean:

completion certificate the same day.

Do I Need to Notify Building Control When the Work Is Complete?

Yes.

Current Building Regulations procedures include formal completion notification requirements.

The project should not simply finish on site without informing the Building Control body.

Relevant dutyholder information and declarations may also be required.

When Should Completion Be Notified?

Current procedural guidance requires relevant notices in connection with completion.

For certain work, notification to the local authority is required within 5 days of completion or occupation, whichever occurs earlier.

The applicable procedure should be followed for the particular project.

Why Can a Completion Certificate Be Delayed?

Possible causes include:

• final inspection not arranged;
• outstanding defects;
• missing electrical certification;
• missing structural information;
• unresolved Building Control comments;
• missing dutyholder declarations;
• outstanding ventilation or commissioning information;
• construction differing from the approved design.

These should be dealt with before the project team considers the Building Control process finished.

Full Plans Approval Is Not the End of Building Control

This is worth repeating.

There are several separate stages:

Stage 1

Technical design.

Stage 2

Full Plans assessment.

Stage 3

Formal plan decision.

Stage 4

Construction.

Stage 5

Inspections.

Stage 6

Completion process.

Stage 7

Completion certificate.

When someone says:

“I've got Building Regs approval.”

they may only mean Stage 3.

The project still has to complete the later stages.

How Long Does Building Regulations Take for an Extension?

For a conventional extension, allow for:

Technical Design

Often days to a few weeks.

Full Plans Assessment

Normally up to:

5 weeks

or:

2 months with consent.

Construction Inspections

Throughout the building programme.

Completion

After works are finished and Building Control is satisfied.

A typical extension can therefore remain within the Building Control process for several months from first technical design to final certificate.

How Long Does Building Regulations Take for a Loft Conversion?

The formal Full Plans period is the same.

But the design stage can be more involved because a loft conversion can require:

• structural calculations;
• new floor;
• beams;
• fire strategy;
• staircase;
• roof alterations;
• insulation;
• ventilation.

The technical package should therefore be started early.

How Long Does Building Regulations Take for a Garage Conversion?

A straightforward garage conversion can have a relatively simple technical design.

But delays can arise where there are questions about:

• garage-door foundation;
• floor insulation;
• damp-proofing;
• wall insulation;
• structural opening;
• drainage.

The formal Full Plans period is still normally five weeks or two months with consent.

How Long Does Building Regulations Take for a Load-Bearing Wall?

A structural opening can be a much smaller project.

The technical stage may consist primarily of:

• survey information;
• beam calculations;
• support details;
• Building Control notification/application.

A Building Notice may sometimes be used where legally available.

However, the steel should not be ordered until the structural design is finalised.

How Long Do Structural Calculations Take?

There is no statutory government period for private structural-design work.

The turnaround depends on:

• provider;
• project;
• complexity;
• information available.

A single steel beam can be much quicker to design than:

• multiple-storey structural alterations;
• frames;
• foundations;
• complex roof work.

Always distinguish the structural designer's turnaround from Building Control's assessment period.

Can Structural Calculations Delay Building Regulations Approval?

Yes, if they are required but not prepared.

For example:

Full Plans submitted

↓

Building Control requests B1 calculation

↓

Designer must be appointed

↓

Information gathered

↓

Calculation prepared

↓

Drawing updated

↓

Response submitted

Preparing structural information before submission can avoid this sequence.

Does Planning Permission Delay Building Regulations?

Planning and Building Regulations are separate.

You can sometimes begin technical Building Regulations design before the planning decision is issued.

This can save time.

But there is a risk:

if planning requires the design to change, some technical work may need to be revised.

Should I Wait for Planning Approval Before Starting Building Regs Drawings?

It depends on planning risk.

Lower Planning Risk

The technical stage may overlap planning to save programme time.

Higher Planning Risk

Waiting until the design is more settled can reduce abortive technical work.

A sensible programme balances:

• time;
• cost;
• risk of redesign.

Can Planning and Building Regulations Run at the Same Time?

Potentially, yes.

There is no universal requirement that all technical design must wait until planning is approved.

For projects with tight programmes, the stages can overlap.

However, the client needs to accept the risk that planning amendments may require corresponding Building Regulations revisions.

How Early Should I Start Building Regulation Drawings?

For a project where a builder is expected to start on a fixed date, allow enough time for:

• drawing preparation;
• structural design;
• revisions;
• Full Plans assessment;
• tendering or final contractor pricing.

Starting only a few days before construction can put unnecessary pressure on the technical design.

Example: Planning a Builder Start in 8 Weeks

Suppose your contractor is available in:

8 weeks.

A better programme could be:

Week 1

Upload existing plans.

Week 1–2

Building Regulation drawings and structural calculations.

Week 2

Submit Full Plans.

Week 2–7

Building Control assessment.

Week 7–8

Resolve final pre-start matters.

Week 8

Construction begins.

This gives the technical stage room to operate.

Again, it is an illustrative programme, not a guaranteed timeline.

Can I Start Building While Building Control Is Reviewing My Plans?

Potentially for ordinary non-higher-risk work.

But doing so reduces the buffer available to respond to changes.

If the work reaches a disputed technical element before the design is settled, construction may pause.

The safest programme is not always the fastest-looking programme.

Can Building Regulations Approval Expire?

Yes.

Current procedural guidance states that Building Control approvals and notices can lapse if work has not been commenced within three years.

The legal meaning of commencement matters.

Simply making a minor symbolic start should not automatically be assumed to preserve approval.

Why the Three-Year Period Matters

A homeowner might:

• obtain Full Plans approval;
• delay the project;
• return several years later.

If the work has not properly commenced within the required period, the old approval may no longer remain effective.

Check the Building Control position before relying on historic approvals.

Important 2026–2028 Transition

The Future Homes and Buildings Standards introduce changes to Building Regulations in England.

For ordinary non-higher-risk work, the relevant changes come into force on:

24 March 2027

There are transitional arrangements.

Where a relevant:

• Building Notice;
• initial notice;
• or Full Plans application

has been given before 24 March 2027, earlier standards can continue to apply to the relevant building where the work is properly commenced before:

24 March 2028

This means the date of submission and the date of commencement can materially affect which technical standards apply.

Should I Rush an Application Before a Regulation Change?

Do not rush an incomplete submission simply to chase a date.

Transitional rules can be technical and project-specific.

The project should:

• use the correct procedure;
• contain reliable information;
• satisfy the applicable commencement requirements.

Where the timing affects the standards that apply, confirm the position carefully with the relevant project professionals and Building Control body.

Higher-Risk Buildings: The Timescale Is Different

Higher-risk buildings in England use the Building Safety Regulator rather than the ordinary domestic Building Control process described above.

The statutory assessment periods are generally:

New Higher-Risk Building

Up to:

12 weeks

Work to an Existing Higher-Risk Building

Up to:

8 weeks

unless an extension is agreed.

These are statutory assessment periods.

Actual experience can differ.

Are Higher-Risk Building Applications Actually Decided Within 12 Weeks?

Not always.

This distinction matters.

The Building Safety Regulator's current guidance gives the statutory assessment period as up to 12 weeks for new HRBs and 8 weeks for existing HRBs, unless extended.

However, current 2026 performance data shows that actual median approval times have often been substantially longer.

For the 12-week period to 1 August 2026, the Building Safety Regulator reported a median determination time of around:

22 weeks

for new higher-risk buildings and conversions.

That has improved considerably from earlier periods but remains longer than the statutory target in many cases.

Ordinary homeowners carrying out house extensions, loft conversions or garage conversions should not confuse HRB Gateway 2 timescales with normal domestic Building Control.

Why Are Higher-Risk Applications Slower?

Higher-risk buildings can involve much more complex assessment of:

• structural safety;
• fire safety;
• design coordination;
• dutyholder information;
• change control;
• compliance documentation.

The Building Safety Regulator also states that processing time depends on:

• complexity;
• quality of the application;
• workload.

This article's five-week Full Plans figure should therefore not be applied to HRB projects.

What Is the Fastest Building Control Route?

There is no universally “fastest” route once the entire project is considered.

Building Notice

can allow the earliest physical start.

Full Plans

can offer more pre-construction certainty.

RBCA

can provide its own commercial review programme.

The right choice depends on:

• complexity;
• programme;
• technical design;
• risk.

Fast Start vs Fast Finish

This distinction is important.

Consider two approaches.

Project A

Starts quickly.

Technical design incomplete.

Queries arise on site.

Work stops.

Beam redesigned.

Drain moved.

Insulation changed.

Project B

Spends more time before construction.

Technical design coordinated.

Structural calculations complete.

Building Control review substantially resolved.

Builder starts later.

Construction progresses with fewer avoidable design interruptions.

Project B may finish first.

How Can I Reduce Building Regulations Delays?

There are several practical steps.

1. Start Technical Design Early

Do not wait until the builder arrives.

2. Use Good Existing Drawings

Upload the planning PDFs or DWGs you already have.

3. Finalise the Layout

Avoid repeatedly moving structural openings during technical design.

4. Prepare Structural Calculations Early

Especially before ordering steel.

5. Investigate Unknowns

Such as foundations, drainage and existing structure where they materially affect design.

6. Submit a Coordinated Package

Make sure calculations and drawings match.

7. Respond Quickly to Building Control

Do not let technical queries sit unanswered.

8. Book Inspections Properly

Do not cover critical work prematurely.

9. Record Changes

Ensure site changes are coordinated.

10. Close Out Completion

Arrange the final inspection and supply outstanding documentation.

A Good Submission Can Be Faster to Assess

Building Control cannot approve what it cannot understand.

A clear package should make it easy to identify:

• existing construction;
• proposed construction;
• relevant details;
• structural elements;
• supporting calculations.

This does not mean excessive drawings are always better.

The goal is:

enough project-specific technical information to explain the work clearly.

Common Timeline Mistakes

Mistake 1: “Planning Is Approved, So I Can Start Tomorrow”

Building Regulations may still need to be dealt with.

Mistake 2: “Building Control Takes 5 Weeks, So I'll Get Drawings in Week 5”

The drawings come first.

Mistake 3: “Building Notice Means Approval in 2 Days”

It does not.

Mistake 4: “My Builder Can Sort the Beam Later”

Late structural design can delay fabrication and construction.

Mistake 5: “Building Control Will Tell Us How to Design It”

Building Control assesses compliance; it does not become the designer.

Mistake 6: “Approval Means the Project Is Finished With Building Control”

Inspections and completion still follow.

Mistake 7: “I'll Arrange the Final Certificate When I Sell”

That can be far more difficult than closing out the process properly at completion.

How Long Should I Allow Before Construction?

For a technically involved domestic project, it is sensible to work backwards from your construction date.

You need to account for:

• technical design;
• structural calculations;
• Building Control assessment;
• possible revisions;
• contractor pricing;
• ordering structural materials.

The appropriate buffer depends on the project.

But if you have an extension, loft conversion or structural alteration planned, starting the Building Regulations stage several weeks before site work is far better than leaving it until the contractor is ready to start.

Building Regulations Timeline for an Extension

A useful planning framework is:

Stage 1 — Planning / Existing Design

Project layout settled.

↓

Stage 2 — Building Regulation Drawings

Technical construction developed.

↓

Stage 3 — Structural Calculations

Engineered elements designed.

↓

Stage 4 — Building Control Submission

Full Plans or other appropriate route.

↓

Stage 5 — Assessment

Normally five weeks for local-authority Full Plans.

↓

Stage 6 — Construction

Inspections take place.

↓

Stage 7 — Completion

Final information and inspection.

↓

Stage 8 — Completion Certificate

Usually within eight weeks of completion under Full Plans where the work complies.

That is the real Building Regulations timeline.

How BuildRegs Can Help Before the Clock Starts

If you already have planning drawings, you may already have the base information needed for the technical stage.

BuildRegs can review:

• PDF drawings;
• DWG files;
• sections;
• elevations;
• planning approval drawings;
• existing structural information.

The project can then be scoped for:

• Building Regulation drawings;
• structural calculations;
• relevant technical details.

BuildRegs Typical Turnaround

Suitable projects typically take around:

7 working days

for the agreed Building Regulation drawing and structural-calculation package, subject to receipt of all required information.

That means you can plan the project in two distinct stages:

BuildRegs

Technical design.

Building Control

Independent regulatory assessment.

Keeping these stages separate makes your programme much easier to understand.

How Much Does the Technical Package Cost?

Current BuildRegs guide prices include:

Single-Storey Extension

From £799

Double-Storey Extension

From £999

Loft Conversion

From £849

Garage Conversion

From £749

Structural Opening / RSJ Calculations

From £249

The project is reviewed first and a fixed quotation is confirmed before you proceed.

What Should I Upload?

Send whatever you already have.

Useful information includes:

• planning drawings;
• permitted-development drawings;
• PDFs;
• DWGs;
• existing and proposed plans;
• elevations;
• sections;
• photographs;
• planning decision;
• Building Control comments;
• existing structural calculations.

You do not need to determine whether the drawings are technically complete before uploading them.

That is part of the review.

How BuildRegs Works

1. Upload Your Plans

Send the project drawings you already have.

2. Scope Review

The technical requirements are reviewed.

3. Fixed Quote

You receive the price before deciding whether to proceed.

4. Technical Design

Building Regulation drawings are prepared.

5. Structural Calculations

Relevant structural calculations are prepared where included in the agreed scope.

6. Digital Delivery

The completed documents are provided for the Building Control process.

Frequently Asked Questions