In-house structural engineering
House Extension
Structural Engineer.
Structural drawings, calculations and connection design for your house extension, coordinated with your plans.
Designed in house. Typical turnaround: seven working days once we have the agreed plans and information.
The short answer
Do You Need a Structural Engineer?
You may need a structural engineer for new openings, roof supports, floors or foundations. Even a small side return can need a steel frame. Your structural engineer checks how loads pass through the existing house and new work to the ground.
Consult a structural engineer while the layout can still change. A structural feasibility review can identify limits early. Beam depths, column positions and foundation requirements can affect your room, door heights and budget.
- When to ask: before removing a load-bearing wall, ordering steel or fixing a wide opening.
- What you receive: calculations, structural drawings and connection design for the agreed scope.
- Working with your plans: we design in house or work from your architectโs drawings.
Designed around your house
Structural Design That Works With Your Extension
We design beams, frames and foundations around your extension plans. Your package brings calculations, drawings and connections together, so your builder can see how the structure fits.
Designed in house
10 yearsโ experience
Our structural engineer brings experience from house projects and major reinforced-concrete work.
A clear programme
Seven working days
Typical design turnaround once we have the agreed plans and information. We confirm your projectโs programme.
Support throughout
Building Control support
Design queries included, with replies within two working days. Call or email our team throughout your project.
Your structural package
Structural Calculations.
Structural calculations, drawings and connection design for your agreed work. We coordinate the supports with your house plans and explain the details your builder needs. Site visits cost extra.
Existing Building Checks
Your structural engineer reviews the walls, floor directions and existing supports. Hidden construction or foundations may need opening up before we can confirm the design.
Steel Beams and Columns
Beam strength, movement and bearings checked against the loads above, supports below and available floor and ceiling space.
Box Frames and Connections
Where a simple beam cannot suit the opening, we design the frame, columns, joints and supports together.
Foundations and Ground Beams
New loads need suitable support. We assess foundation requirements using the house and ground information, with existing foundations exposed where needed.
Floor, Roof and Stair Openings
Supports for floors, rooflights, lanterns and stairs within the agreed scope. Loft and extension loads considered through the house.
Details for Your Builder
Our structural drawings and calculations show the agreed supports. The builder and steel supplier must check site sizes before fabrication.
What it costs
House Extension Structural Engineer Costs.
Starting design fees are shown below, plus VAT. Send your plans for a project quote. The complexity of the project affects your fee: openings, loads, existing construction and foundation requirements.
What the Design Fee Covers
Calculations, drawings and connection design for the agreed scope. Steel supply, installation and building costs are separate.
Site Visits and Changes
Site visits cost extra. Your quote confirms the scope, VAT and how later plan changes will be handled.
Steel beam design
Calculations, drawings and connection design for the agreed scope.
Box frame design
Calculations, drawings and connection design for the agreed scope.
Loft conversion structural design
Calculations, drawings and connection design for the agreed scope.
Single-storey extension structural design
Calculations, drawings and connection design for the agreed scope.
These are starting fees. We confirm the total for your project before work starts.
Real structural evidence
Wrottesley Road: Working Around the Staircase.
At 40 Wrottesley Road, we designed the architecture and structure for a major rebuild of a semi-detached house, including side and rear extensions and a loft conversion.
Removing the flank wall made room for the staircase. The columns could not sit centrally, so our design used box frames.
Following the Loads
The package brings together two box-frame beams, a linking beam, a ground beam and floor and roof supports. Existing foundations taking extra load must be exposed and checked before reuse.
Connections Designed Together
We detailed the frame-column joints at the top and base, plus the concrete around the ground beam. The project is under construction.
CLIENT FEEDBACK
Loved by homeowners and builders.Trusted across every detail.
โGreat experience working with them. Professional, responsive, and technically thorough throughout the project. The structural advice and drawings were clear and delivered promptly. Would definitely recommend their services.โ
โExcellent service! Very professional and punctual . Competitive price.โ
โWe used AC Design Solution for planning permission on a single storey extension and loft conversion, plus the building regulation drawings, structural calculations, and party wall surveying. They handled the whole process well and kept us updated throughout, which made things a lot less stressful than we expected. The drawings and structural work were solid, and the party wall side went smoothly too. Would recommend them to anyone needing help with planning and building regs.โ
โI had an issue on site that required appointing a Party Wall Surveyor. My architect recommended Zubear from AC Design Solution, who I must say is extremelyย experiencedย and kept me updated throughout. We faced a challenging experience with the council and their surveyor, but Zubear overcame the issues, allowing me to get my Party Wall matters sorted out.โ
Your extension
Structural Engineering for Your Extension.
Extensions With Lofts
Floor strengthening, roof changes and staircase openings coordinated with the extension. Your structural engineer checks the supports through each floor below.
Rear and Side Extensions
Supports for rear openings, roofs and foundations. Side-return and wraparound layouts may need linked beams or frames, particularly when removing a corner.
Double-Storey Extensions
Extra floor and roof loads, checked through the supports below. Your structural engineer assesses whether existing walls and foundations can take the increase.
Building an Extension: The Design Process.
1. Send Your Plans
Share existing and proposed drawings, photos and the postcode. Tell us about headroom, glazing or column positions that matter to you.
2. Check the House
Your structural engineer identifies missing information and agrees any structural inspection, photos or opening-up checks needed before design.
3. Design the Supports
Your structural engineer checks beams, joints, bearings and foundations together. We discuss changes that affect your room layout or levels.
4. Issue the Package
Typical design turnaround is seven working days once the scope and required information are agreed. Site checks and later changes can add time.
Load-Bearing Walls, Headroom and Columns.
Keeping Ceiling Height
A deep beam can reduce headroom or door height. We check the available space and beam movement against the glazing supplierโs requirements.
Removing a Corner
Keeping a wall pier can change the design. Removing the whole corner may need a frame and different foundations. See our load-bearing wall removal service.
Support After Design.
Questions About the Design
Call or email our in-house structural engineer with questions about the agreed design. Building Control enquiries are included, with replies within two working days. Site visits cost extra.
Architecture and Engineering
Planning permission, Building Regulations approval and structural design cover different matters. The structural engineer checks the agreed load-bearing elements; the wider technical package covers other requirements. For the wider technical plans, see our Building Regulation drawings. Our house extension drawings service covers the architectural plans.
Common questions
Before you begin.
How Much Does a Structural Engineer Cost?
The opening, loads and existing building affect the structural engineerโs fee. Compare the scope when requesting estimates for a structural design: drawings, connections, visits and later revisions may be priced differently.
Do I Need an Architect and a Structural Engineer?
An architect plans the layout and appearance. A structural engineer checks the supporting structure. We provide both services in house or coordinate our structural engineering with your own architect.
What Does a Structural Inspection Cover?
A structural engineer may carry out an inspection to assess a specific structural concern. They examine accessible parts and advise on further checks. A visit cannot prove every hidden element is structurally sound.
When Should I Hire a Structural Engineer?
When you have an initial layout, before ordering steel or starting structural work. Ask earlier if a wide opening or column position could change the plans.
Do I Need a Site Visit?
It depends on the information available and the work proposed. We agree any visit and its extra fee. Hidden construction may still need opening up.
What if the House Has Movement or Cracking?
Tell us about subsidence, repairs or previous reports before making structural changes. Possible structural defects or a problem with the structure need assessment before extension design. See our structural surveys.
Can My Builder Choose the Beam?
A structural engineer can provide a beam design for the opening, loads and supports. Your builder and steel supplier must then check site dimensions before ordering.
How Do I Choose a Structural Engineer?
When comparing local structural engineers or structural engineering firms, ask about relevant house projects, qualifications and who checks the design. Verify chartered titles and membership claims with either the Institution of Structural Engineers or the Institution of Civil Engineers. The Institutionโs domestic-client guide explains what to check. Do not assume every practice uses chartered structural engineers.
Who Handles Temporary Support?
The builder must plan the sequence and temporary support. Agree who designs temporary works and arranges inspections. Read about temporary works for structural alterations.
Does My Extension Need Party-Wall Advice?
Work near a shared wall or neighbouring foundations may need separate advice. Our party-wall surveyor service can help you understand the next steps.
Tell us what you are planning
Letโs Talk About Your Extension.
Get in touch with your plans and tell us what you want to achieve. We will confirm the structural scope, fee and next steps.
Continue your research
Structural Advice and Guidance.
Steel Connection Design UK: Types, Calculations and Practical Considerations
Steel connections are vital to the strength and stability of any steel structure. This guide covers common connection types, structural roles, fabrication methods, and key considerations to ensure safety, compliance, and performance in steel-framed construction.
Structural Alterations in Period Homes: Problems We Find on London Renovations
Opening up the kitchen, removing a wall or converting the loft can look straightforward on a floor plan. In a period home, however, the structural work behind that change can be considerably more complicated.
How to Identify a Load Bearing Wall
Before you knock down a wall, find out if it’s load-bearing. This guide explains how to identify load-bearing walls, what wall removal involves, and when to call a structural engineer.