If you are planning a house extension, loft conversion or major renovation, Building Regulation drawings are one of the key technical stages between having a design and being ready to build.
But homeowners often find it difficult to work out what they should actually budget for.
A quote described as “Building Regs drawings” may cover the architectural technical package but not structural calculations. Another may include submission to Building Control but exclude the Building Control application fee. More complex projects may also need specialist information for energy performance, fire safety, drainage or other technical matters.
That is why comparing prices without comparing the scope can be misleading.
As checked in August 2026, AC Design Solution’s published prices for Building Regulation drawing packages start from £600 for a single-storey extension, £600 for a loft conversion and £1,300 for a double-storey extension. Basement projects are quoted individually. These are AC Design Solution’s own current starting prices, not national average fees, and the final cost depends on the scope and complexity of the project. Building Control fees are charged separately.
This guide explains what Building Regulation drawings contain, how much they cost in 2026, what additional fees may apply and how the Building Control process currently works.
Regulatory scope: although people commonly search for “Building Regulation drawings cost UK”, the Building Control procedures discussed below relate primarily to England. Scotland, Wales and Northern Ireland have differences in their regulatory systems.
Building Regulation Drawings Cost in 2026: At a Glance
| Project type | AC Design Solution published starting price |
| Single-storey extension | From £600 |
| Loft conversion | From £600 |
| Double-storey extension | From £1,300 |
| Basement project | Individual quotation |
These published packages cover technical drawing information appropriate to the project. AC Design Solution also states that Building Control submission is included within its service while the Building Control fee itself is charged separately.
The important distinction is that these are first-party AC Design Solution prices. They should not be presented as a general UK average.
What Are Building Regulation Drawings?
Building Regulation drawings are detailed technical drawings and specifications prepared to demonstrate how proposed building work will address the relevant requirements of the Building Regulations. They are different from planning drawings.
Planning drawings are primarily used to describe the proposed development for planning purposes, including its appearance, size and relationship with the existing property and surrounding area. Building Regulation drawings go further into how the project will actually be constructed.
Depending on the work involved, they can address structural design, foundations, insulation, fire safety, ventilation, drainage, roof and floor construction, wall build-ups and the junctions between new and existing elements.
For a homeowner, a useful way to understand the difference is:
Planning drawings explain what you are proposing to build. Building Regulation drawings explain how the building can be technically constructed to satisfy the applicable requirements.
What Should Building Regulation Drawings Include?
There is no single standard drawing set that is appropriate for every project. A straightforward rear extension will require different information from a loft conversion, basement or multi-storey development. The scope should reflect the building and the work being proposed.
A typical domestic Building Regulations package may contain:
| Technical information | What it helps establish |
| Existing and proposed plans | Property layout and scope of alteration |
| Building sections | Foundations, floors, walls and roof construction |
| Elevations | Relevant external construction and openings |
| Wall, roof and floor build-ups | Materials, insulation and construction approach |
| Foundation details | How the new structure will be supported |
| Thermal information | Compliance with relevant energy requirements |
| Fire-safety information | Escape, separation and protection where applicable |
| Ventilation information | How adequate ventilation will be provided |
| Drainage details | Foul and surface-water arrangements where relevant |
| Structural coordination | Position of beams and other structural elements |
| Technical notes/specifications | Additional requirements needed to explain construction |
AC Design Solution’s current Building Regulation drawings service states that its packages can include plans, sections, construction details, insulation information, fire-safety information, ventilation, drainage and structural coordination depending on the project.
A strong technical package is not simply produced for a Building Control officer. It also gives the contractor clearer information for pricing and construction.
How Much Do Building Regulation Drawings Cost in 2026?
There is no reliable single national fee for Building Regulation drawings. The price depends on what actually needs to be designed and documented. For example, two single-storey extensions may have almost identical floor areas but very different technical requirements. One might use straightforward masonry construction and a relatively small structural opening. The other might contain wide glazing, multiple steel beams, complex roof geometry and drainage changes.
The second project requires more coordination even though both could be described online as “a single-storey extension”.
AC Design Solution’s current published starting prices provide a more useful reference for its own services:
Single-storey extensions start from £600. Loft conversions start from £600. Double-storey extensions start from £1,300. Basement work is individually quoted.
These prices should be presented as AC Design Solution’s current 2026 pricing, rather than being blended with unsupported national averages.
What Can Increase the Cost of Building Regulation Drawings?
The size of a project matters, but it is not the only factor. Technical complexity can have a greater effect on the final fee. Large structural openings, complicated foundations, unusual roof forms, basement construction, extensive glazing or significant alterations to an existing property may require additional design and coordination.
The starting information also matters. If accurate existing and planning drawings are already available, converting the approved design into a technical package may be relatively straightforward. Where the existing property first needs to be measured or the proposed layout still requires development, additional work may be necessary.
Structural calculations, specialist energy assessments and other consultant information can also be separate from the architectural Building Regulation drawings.
For that reason, the most useful question to ask when comparing quotations is not:
“Who has the cheapest Building Reg drawings?”
It is:
“Exactly what information and professional services are included in this fee?”
Are Structural Calculations Included in Building Regulation Drawing Costs?
Not automatically. Structural drawings and calculations perform a different technical role from architectural Building Regulation drawings, although the two packages often need to be coordinated closely.
If your project involves removing a load-bearing wall, creating a large structural opening, supporting a new roof, installing steel beams or altering foundations, a structural engineer may need to calculate how loads will be transferred safely through the building.
For example, an architectural drawing may establish the position and dimensions of an opening between the existing house and a new extension. The structural engineer then determines what beam, bearings, columns or other supporting structure may be required.
AC Design Solution provides separate structural calculations and drawings for Building Control for projects where engineering design is required. Its structural service specifically covers calculations for elements including beams, foundations, floors and roofs.
When comparing fees, homeowners should therefore confirm whether structural engineering is included, separately quoted or not required for the proposed work.
How Much Are Building Control Fees in 2026?
The Building Control fee is separate from the professional fee charged for preparing technical drawings. There is not one fixed national Building Control application fee.
GOV.UK states that local-authority fees are based on the authority’s costs. The amount can depend on factors such as the work involved, site inspections, number of dwellings and total floor area. Private Registered Building Control Approvers negotiate their fees directly with clients.
That is why publishing a generic statement such as “a Building Control application costs £700” is not sufficiently accurate for a national guide. Instead, homeowners should budget separately for:
Building Regulation drawing fee + structural/specialist professional fees where required + Building Control fee.
The actual Building Control fee should then be obtained from the chosen Building Control body for that specific project.
Who Can Provide Building Control in England in 2026?
This is one of the most important updates from the previous version of this article. The older 2025 article referred to private Approved Inspectors.
For current Building Control work, the relevant private-sector term is Registered Building Control Approver (RBCA).
For work that does not involve a higher-risk building, GOV.UK says Building Control approval can generally be obtained from a local council or a private Registered Building Control Approver. Private Building Control businesses must be registered with the Building Safety Regulator.
For projects involving higher-risk buildings, the Building Safety Regulator has a separate Building Control role.
Most homeowners carrying out ordinary domestic extensions and loft conversions will be dealing with either the local authority or an RBCA.
Full Plans vs Building Notice: What Is the Difference?
Homeowners frequently come across two routes when investigating Building Regulations approval: Full Plans and Building Notice.
For ordinary work that is eligible for these routes, a Full Plans application provides Building Control with detailed technical information before the work proceeds.
GOV.UK describes Full Plans as the most thorough option and currently states that applicants can expect a decision within five weeks, or within two months with their consent.
A Building Notice follows a different process. GOV.UK describes it as being for smaller projects, and says work can generally start two days after the notice has been submitted. Unlike Full Plans, you do not receive formal approval of detailed plans beforehand.
| Full Plans | Building Notice |
| Detailed technical information submitted | Less detailed information at the outset |
| Formal assessment of plans | No formal plans approval in the same way |
| Decision normally within 5 weeks, or 2 months by agreement | Work can generally begin 2 days after submission |
| Gives the project team a clearer approved technical reference | Greater reliance on compliance being demonstrated during construction |
| Often useful where substantial technical coordination is required | More commonly associated with simpler eligible work |
A Full Plans approval should not be described as a guarantee that everything built on site will automatically comply. Construction still has to follow the relevant requirements and is subject to Building Control inspection.
What Is Building Regulations Regularisation?
Regularisation is used in a different situation. It is a retrospective Building Regulations process for eligible building work that was previously carried out without the necessary Building Control approval.
GOV.UK states that a regularisation application can only be made through a local-authority Building Control body, and that this route applies to eligible work carried out after 11 November 1985.
Building Control may need to inspect the existing construction. In some cases, elements of the work may have to be exposed or altered before the authority can determine whether a regularisation certificate can be issued.
This is especially relevant when a homeowner discovers previous unauthorised building work after purchasing a property.
Regularisation should not be confused with retrospective planning permission. They deal with different regulatory issues.
Building Regulation Drawings for Extensions
Extensions bring several technical requirements together in a relatively small area. The new foundations need to respond appropriately to the proposed structure and site conditions. External walls and roofs need suitable build-ups. New openings between the existing house and extension may require engineering design. Drainage, ventilation, insulation, glazing and fire safety may also need to be coordinated.
This is why Building Regulation drawings for extensions contain more technical information than a planning application drawing set.
If you are specifically planning a rear extension, AC Design Solution also has a detailed rear extension Building Regulations guide covering the technical considerations that commonly arise.
Resolving this information before construction gives the builder a much clearer technical basis for pricing the project and reduces the amount of design decision-making that has to happen after work has started.
Building Regulation Drawings for Loft Conversions
Loft conversions can be deceptively complex from a Building Regulations perspective. Even where the proposed room layout looks straightforward, the existing roof may need structural alteration. A new staircase needs to work with the existing floor plan, while fire safety, insulation, ventilation, headroom and structural support must all be coordinated within a restricted space.
For that reason, the Building Regulation package usually contains more information than simply adding dimensions to the planning drawings.
AC Design Solution’s loft conversion Building Regulation drawings service is specifically structured around this type of technical coordination.
What Changed Under the Building Safety Regime?
The Building Safety Act and subsequent amendments to the Building Regulations have increased the emphasis on clear responsibility and professional competence.
Since 1 October 2023, the Building Regulations dutyholder regime has applied to building work in England. Relevant dutyholders include clients, designers, principal designers, contractors and principal contractors. They are expected to plan, manage and monitor their work, cooperate with other dutyholders and ensure that people carrying out design or building work have appropriate competence. This applies beyond major high-rise schemes.
For homeowners, it reinforces an important principle: Building Regulation drawings should not be treated as an isolated piece of paperwork purchased simply to “get approval”.
They form part of the wider design information that architects, architectural technologists, engineers, contractors and Building Control need to coordinate.
What Has Changed in 2026?
There is an important regulatory development to understand when updating an article specifically for 2026. The government published the Future Homes and Buildings Standards and new 2026 editions of Approved Documents L and F on 24 March 2026.
However, publication in 2026 does not mean that every domestic extension being designed in 2026 immediately falls under those new requirements.
The Building Regulations amendments associated with the new standards generally come into force on 24 March 2027. Certain provisions relating to higher-risk building work come into force later, on 24 September 2027, and transitional arrangements apply.
That distinction is important for homeowners and designers.
A technically accurate 2026 article should therefore avoid saying that “the new 2026 standards now apply to every project”.
Which requirements apply depends on the project, the date of the relevant application or notice, commencement and the transitional rules. For authoritative technical guidance, refer to the government’s Building Regulations and Approved Documents index.
How Long Does Building Regulations Approval Take?
There are two separate timescales: preparing the technical design and obtaining the relevant Building Control decision.
Drawing preparation depends on the complexity of the project and the quality of the information already available.
AC Design Solution currently states a typical 5–10 working day delivery period for its Building Regulation drawing packages, although an individual project may vary depending on what information and coordination are required.
For a Full Plans application, GOV.UK currently states that a decision can normally be expected within five weeks, or two months where the applicant agrees to the extended period.
Building Control may also request further information or amendments during the review. The programme should therefore allow time for both drawing production and the formal Building Control process rather than treating them as the same stage.
What Happens During Construction?
Receiving Building Control approval does not mean Building Control involvement has finished. Inspections take place during construction so relevant stages of the work can be reviewed.
Exactly which inspections are needed depends on the project, but they may relate to foundations, drainage, structural work, insulation and completion.
The contractor should also work from the current coordinated technical information. If a construction detail is changed significantly on site, it should be reviewed rather than assuming that the alternative automatically meets the same requirements as the approved design.
This is one reason technically clear drawings provide value beyond the application itself. They become part of the working information used throughout construction.
What Is a Building Regulations Completion Certificate?
A completion certificate is an important record at the end of the Building Control process. Once relevant work has been completed and the Building Control body is satisfied with compliance, the completion process can be concluded.
GOV.UK currently states that under the Full Plans route you will usually receive a completion certificate within eight weeks of completion of the building work, provided that it complies.
This is an important correction to the previous 2025 article, which stated that completion certificates were usually issued within two weeks.
Keep the completion certificate together with your Building Regulation drawings, structural calculations and other relevant project records. Having a clear technical record can be valuable when the property is later sold, refinanced or altered again.
Are Building Regulation Drawings the Same as Construction Drawings?
Not necessarily. Building Regulation drawings are prepared to provide sufficient information relating to technical compliance and Building Control. A detailed construction package can go further.
Depending on the complexity of the project, construction information might also include detailed setting-out dimensions, junction drawings, fixing information, specifications and product-specific construction details required by the contractor.
For straightforward domestic projects there can be significant overlap between the two.
For a complex project, additional construction information may be needed after Building Regulations approval.
When obtaining a quotation, ask exactly what level of technical detail the package includes and whether it is intended only for Building Control or also for direct use by the contractor.
How Should You Budget for Building Regulation Drawings?
A practical budget should separate the different professional and regulatory costs rather than putting everything under one “Building Regs” figure.
Start with the drawing package itself. Then establish whether structural calculations are necessary and whether any specialist reports or calculations will be needed. Finally, obtain the actual fee from the chosen Building Control body.
Also check whether your quotation includes revisions following Building Control comments, submission administration and coordination with other consultants.
AC Design Solution currently states that its Building Control submission and reasonable amendments are included in its technical drawing service, while the Building Control fee is charged separately.
This makes comparisons between providers much more meaningful than looking only at the headline starting price.
Do Building Regulation Drawings Save Money During Construction?
The drawings themselves do not guarantee a cheaper build, but good technical design can reduce uncertainty.
A contractor pricing only from planning drawings may have to make assumptions about foundations, insulation, structural details, drainage and construction junctions. Those assumptions can create variations later.
A coordinated technical package gives the project team more information before work begins and creates an opportunity to identify conflicts between architecture, structure and construction earlier.
For homeowners, that is one of the main practical reasons to prepare Building Regulation drawings properly rather than seeing them only as an administrative requirement.
Conclusion
Understanding Building Regulation drawings cost in 2026 means looking beyond one headline fee. For a straightforward domestic project, AC Design Solution’s current technical drawing packages start from £600. More complex projects cost more because the amount of design, structural coordination and technical information increases.
Building Control charges should be budgeted separately, as should structural engineering and other specialist work where required.
The regulatory framework has also changed since older Building Regulations cost guides were written. Private Building Control now operates through Registered Building Control Approvers, dutyholder responsibilities are established across design and construction, and the Future Homes and Buildings Standards published in 2026 have specific future commencement and transitional arrangements.
A good Building Regulation package therefore does more than support an application. It gives the homeowner, designer, structural engineer, contractor and Building Control body a clearer technical basis from which to work.
If you are preparing an extension, loft conversion or residential alteration, AC Design Solution can provide Building Regulation drawings and technical design support based on the requirements of your individual project.
