Removing Load-Bearing Walls
Creating an open-plan kitchen or living area can require a designed beam and suitable supports to carry the weight above the opening.
Structural Engineering Calculations
Structural Calculations for Your Next Stage of Building
Understand how your proposed structure will be supported, with calculations based on your architectural design.
Structural engineering calculations assess the strength and load-bearing capacity of the elements that support a building. They help establish suitable sizes, materials and support arrangements for the proposed work.
Planning By Design can help you progress from architectural plans to the structural calculations your project needs. Send us your drawings so we can review the design and provide a project-specific quotation.
Do I Need Structural Engineering Calculations?
If your proposal changes how a building carries weight, or introduces a new structure, you may need structural calculations. The requirement depends on the design and the existing building, rather than simply the floor area.
Extensions & New Buildings
New floors, roofs, walls and foundations need a coordinated structural approach appropriate to the proposed design.
Loft Conversions & Roof Changes
Changes to roof structure and the creation of usable floor space can require checks on existing and proposed structural elements.
Larger Openings & Alterations
Widening doors or windows, changing supports or making other structural alterations may require calculations for the affected elements.
Not sure whether the work affects a load-bearing element? Share your plans and discuss the next step before starting structural alterations.
Design-Led Scope
Calculations based on your architectural plans.
Coordinated Services
Architecture, planning and technical design support.
Clear Quotations
A defined scope for your project.
Real Examples
View a sample calculation package below.
What Do Structural Calculations Cover?
Structural calculations examine the loads acting on a building and how those loads pass through its supporting elements. The engineer assesses the relevant parts of your design and identifies the structural requirements.
Loads & Support
Checks consider the weight of the building, its intended use and relevant environmental loads, together with the way the structure transfers those loads to its supports.
Materials & Dimensions
The design may establish the size and specification of elements such as beams, posts, joists or lintels, depending on the agreed scope.
The information needed varies by project. Existing construction, ground conditions and structural connections may require additional investigation or design work. Your quotation should identify the work included.
Architectural Drawings, Building Regulations & Structural Calculations
These services address different parts of the same project. Keeping them coordinated helps the design information work together.
In England, Approved Document A provides guidance on the structural requirements of the Building Regulations. Requirements and procedures differ across the UK; the applicable route depends on your project location.
When Should I Commission the Calculations?
For projects that need planning permission, we generally recommend waiting until permission is in place and the design is settled before commissioning the full structural calculation package. A design change can mean revised calculations and additional fees.
Some proposals benefit from early structural input to check whether a design is practical. Discuss that need at the design stage, especially where the proposal involves substantial openings or complex alterations.
If your project does not need a planning application, the structural and building regulations requirements still need to be considered. Permitted development does not remove the need to assess the proposed structure.
What We Need to Prepare Your Quote
Please provide your full architectural drawing set so we can understand the proposed work and identify the calculation scope.
Your Plans & Project Details
- Existing and proposed plans, elevations and sections, where available
- The property address and a description of the work
- The latest drawing revision and any planning decision
- Your intended construction programme
Any Supporting Information
- Photographs of the areas being altered
- Existing structural drawings or reports, if available
- Any building control queries already received
- Details of known site constraints or proposed design changes
If you do not yet have plans, our architectural design service can help you reach this stage. The engineer may need further measurements, inspections or investigations before completing the design.
What Will You Receive?
Your quotation will confirm the deliverables for your project. Depending on the design and agreed instruction, the package may include:
Project-Specific Calculations
Calculations for the structural elements included in the agreed scope, based on the relevant drawings and design information.
Structural Specifications
Information identifying the required sizes, materials and support arrangements for the elements being designed.
Supporting Details
Structural sketches or details where included, to explain how the designed elements relate to the architectural proposal.
Information for the Next Stage
A calculation package to be read alongside the relevant drawings by the project team and building control, as applicable.
Site visits, ground investigations, temporary works, construction supervision and later design changes should be agreed separately where required. Ask us to clarify any item you need before instructing the work.
How the Process Works
Share Your Drawings
Send the current architectural plans, project address and a short brief. Let us know your planning status and target dates.
Confirm the Scope & Quote
We review the proposal and identify the calculation work to be quoted, together with any further information needed.
Develop the Structural Design
Once instructed and the necessary information is available, the engineer assesses the relevant loads and structural elements.
Coordinate the Information
The structural information is coordinated with the architectural design. Any changes or unresolved details need to be addressed.
Progress to Building Control & Construction
Use the agreed calculations with the relevant drawings for the next stage. Confirm any required approvals and resolve design queries before the affected work begins.
Structural Engineering: Timing & Costs
How Long Does It Take?
The programme depends on the complexity of the design, the information available and whether investigations or design revisions are needed.
Send your plans and intended start date so we can confirm a realistic timescale. Preparation of the calculations and any building control review are separate stages.
How Much Will It Cost?
We need your architectural drawings before we can quote. Fees depend on the structural work involved, rather than the size of the project alone: a compact but complex alteration may need more design input than a larger, simpler scheme.
Request a tailored quote setting out the agreed scope.
Resolve Design Changes Before Building
Planning permission and structural design address different questions. A planning decision does not confirm that a particular beam, wall or foundation design is suitable, and structural calculations do not replace any required planning or building control approvals.
Calculations also rely on the design information and assumptions used. If the layout, loading or site conditions change, ask the engineer to review the affected design before the work proceeds. Building control may request further information; approval is not guaranteed by commissioning calculations alone.
Example Structural Engineering Calculations
Explore the example calculation package below to see how structural information can be presented. Your own package will depend on the design and the services agreed for your project.
Why Choose Planning By Design?
Coordinated Design Support
Connect your architectural plans with the structural and building regulations information needed for the next stage.
A Project-Specific Approach
Start with the proposed design so the scope reflects the actual work involved.
Clear Next Steps
Understand which drawings and supporting details are needed before progressing.
Award-Winning Practice
Recognised for architectural design and town planning, including the BUILD Architecture Awards 2026.
Transparent Scope
Review the services included in your quotation before you instruct the work.
Structural Engineering FAQs
Can you quote without architectural drawings?
We need the full architectural drawing set to assess the design and prepare a project-specific quote. If you do not yet have plans, speak to us about architectural design first.
Can I send plans prepared by another architect?
Yes. Send the latest drawings for review. We will let you know whether further information or clarification is needed before the structural work can be scoped.
Do I need calculations if my project is permitted development?
Potentially. Permitted development concerns the planning route. The need for structural calculations depends on the building work and the elements affected.
Are structural calculations included in building regulations drawings?
They are related but distinct services. Structural calculations support the structural design; building regulations drawings cover a wider range of technical requirements. Your quotation will confirm which services are included.
Should I wait until I have planning permission?
Where planning permission is required, we generally recommend settling that stage before paying for the full calculation package. Early structural advice may still be useful where it affects the feasibility of the design.
What if my design changes after the calculations are completed?
Tell the project team before building the revised design. The engineer will need to assess whether the calculations or details must change, and additional fees may apply.
Will I need a site visit or investigation?
That depends on the proposal and the available information about the existing building and site. Any necessary inspections, measurements or investigations should be identified and agreed as part of the scope.
Do calculations guarantee building control approval?
No. They provide supporting structural information, but building control may need clarification or further details. The wider project must also address all applicable requirements.
Related Services
Meet the Team Behind Your Project
Find out more about the people behind Planning By Design and discuss how our services can support your next stage.
We have developed a variety of partnerships with businesses that may be able to support your planning application and process. Take a look at our partnerships today to find out more about what each business does and how they might be able to help you.
Ready to Discuss Your Structural Calculations?
Tell us about your project and send your architectural plans. We will help you identify the next step and prepare a quotation for the work required.
