Frequently Asked Questions

Welcome to our FAQ page. Here you’ll find answers to many of the most common questions about our services. If you can’t find what you’re looking for, please don’t hesitate to get in touch with us.

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General

What services do RZA Structures provide?
We offer a full range of structural engineering services — from alterations and extensions to new builds, inspections and expert witness reports. See the full list on our Services page.
Do you work on both residential and commercial projects?
Yes. Most of our work is residential (homeowners, developers and contractors), and we also undertake commercial projects.
What areas do you cover?
We’re based in Essex and regularly work across Essex, Suffolk and London. For desktop reviews and reports, we can often assist UK-wide.
Are you qualified and insured?
Yes. Our engineers are professionally qualified in civil and structural engineering. We carry Professional Indemnity Insurance and can share our current certificate on request.

Planning & Building Regulations

Do I need Planning Permission or just Building Regulations approval?
Planning Permission deals with how your project looks and affects neighbours/the area. Building Regulations check that the work is safe and built to technical standards (structure, fire, drainage, etc.). Many small projects fall under permitted development, but Building Regulations still apply.
We can advise what you need at the start if required. Planning Portal website. Building Regulations approval website.
What are Building Regulations, in simple terms?
They’re the UK rules that make sure buildings are safe and fit for purpose. For structure (Part A), we prepare calculations and drawings so Building Control can check and approve your project. Inspectors also visit site to confirm the work matches the approved plans.
Will you deal with Building Control for me?
Yes, we can submit our calculations and drawings and respond to any technical queries from your chosen Building Control body (local authority or an approved inspector).
How long do drawings and calculations take?
It depends on the scope and how complete the information is. As a guide, a typical two-storey extension package is usually delivered in about 2–3 weeks from receiving the architect’s plans. If you have a tight programme, tell us and we’ll do our best to accommodate.

Design Process

When should I appoint a structural engineer?
Bring us in once you have a measured survey or outline architectural plan. Early input helps avoid costly changes and ensures the design is practical for your budget and site conditions.
What info do you need to start?
Architectural plans (if available), any existing drawings, site photos, your aims (e.g. open-plan kitchen), and known site constraints (trees, drains, access). For some projects a site visit is recommended before final design.
Can you visit site during the build?
Yes. We offer ad-hoc inspections or a tailored site-support package to help deal with unexpected findings (e.g. shallow foundations, hidden steel, drainage conflicts).

Costs & Timing

How much does a structural engineer cost?
Fees vary with complexity. A simple beam design can be a few hundred pounds; larger projects run to the thousands. We’ll give you a clear fixed or itemised quote once we understand the scope.
How do I get a quote?
Send us your address, brief description, any drawings and photos. We’ll review and respond with a tailored fee and timescale. Request a quote
What happens after I receive the drawings and calculations?
Your builder uses these to price and construct, and Building Control checks them for compliance. If site conditions differ from expectations, we’ll advise on revisions or alternative details.

Practical Questions

Can you recommend architects or contractors?
Yes — we can share a shortlist of trusted local professionals who suit your project size and style. You remain free to choose whomever you prefer.
Do you offer virtual consultations?
Absolutely. Video calls work well for early advice and to review drawings/photos. For final design, a site visit may still be required.
Do you do structural reports for cracks or movement?
Yes. We inspect, diagnose likely causes (e.g. settlement, thermal movement, trees/drainage) and set out clear remedial steps for you and your insurer/lender if needed.

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Design Process for Residential Construction Projects

Not sure where to start? The steps are slightly different depending on whether you’re changing the outside of your home (extensions, new openings, loft dormers) or making changes inside (removing a wall, new beams). Below we explain both routes in plain English and show where a structural engineer, architect and Building Control fit in.

Quick overview
  • External works Usually two stages: Planning/Permitted Development → Building Regulations approval.
  • Internal works Often handled via a Building Notice with your structural calculations & drawings.
  • Throughout: your contractor builds to the approved drawings; Building Control inspects key stages.

External Alterations: A Step-by-Step Guide

External changes (like extensions, dormers, new openings in external walls, significant alterations to the roofline, or retaining walls) tend to be more involved because they affect the building envelope and the street scene.

Stage 1 Planning Permission or Permitted Development

Before you build, confirm whether you need Planning Permission or if your scheme fits within Permitted Development (PD) rights. An architect can advise on the rules for your property (location, size limits, materials, overlooking etc.) and prepare the submission.

Good practice:
  • If your project is PD, ask the council for a Lawful Development Certificate. It’s optional, but it provides written proof your design is compliant.
  • Check early for constraints: conservation areas, listed buildings, drains, trees, flood zones.

Stage 2 Building Regulations Approval

Once planning or a lawful development certificate is in hand, you’ll need Building Regulations approval. This confirms the work meets the UK’s technical standards (structure, fire, drainage, insulation, ventilation, etc.).

Who does what?
  • Structural Engineer (RZA Structures): designs beams, lintels, frames, foundations, retaining walls and connections; produces structural calculations and drawings for Part A (Structure).
  • Architect: prepares working/construction drawings that address the other Parts (e.g., thermal, fire strategy, layout details).
  • Building Control (Local Authority or Approved Inspector): reviews submissions and inspects site at key stages.
What gets submitted?
  • Structural calculations and structural drawings (Part A).
  • Architectural drawings/specifications covering relevant Parts (B, C, E, F, L, etc., as applicable).
  • Any supporting documents (e.g., drainage layouts, manufacturer data, product certificates).
Contractor Guide

Your approved drawings form the instruction manual for the builder. Clear details reduce the chance of on-site mistakes and delays. If something unexpected appears during the build (e.g., shallow foundations, a hidden steel, or a drain where you planned a footing), we’ll advise on revisions or alternative details.

Note on recent guidance/updates

Recent changes to regulations and guidance have increased the amount of on-site verification. It’s common for structural engineers to review works during construction and issue updated details where real-world conditions differ from assumptions. We factor this into our service so you remain compliant.

For very simple extensions with a competent contractor already on board, the architect’s role can be lighter. In such cases, the structural engineer may provide the structural design while the contractor coordinates other Building Regulations aspects directly with Building Control. This approach carries higher risk of on-site queries, so it’s best reserved for straightforward projects.

Internal Alterations: The Building Notice Route

Internal structural changes—like removing a load-bearing wall, installing a steel beam, trimming joists for a new opening, or strengthening floors—are often processed via a Building Notice rather than a full plans application.

What is a Building Notice?

It’s a short form submitted to your Local Authority Building Control or a Private Approved Inspector. You typically won’t need planning permission for purely internal works (check if your home is listed or in a special area), but you do need to comply with Building Regulations.

What you’ll need
  • Structural calculations and drawings prepared by a structural engineer (Part A).
  • Basic plans/sections/photos showing the existing structure and proposed alterations.
  • Contractor details and proposed start dates for inspection scheduling.
What Building Control does
  • Checks the structural design (in-house or via a third-party reviewer).
  • Visits site at agreed stages to ensure the works match the design (e.g., bearing, padstones, bolted connections, fire protection).
  • Advises on non-structural requirements, such as fire protection to beams, sound insulation, or ventilation where relevant.

Typical sequence for internal works

  1. Initial advice: Send us photos and any existing drawings; we’ll confirm if a site visit is needed.
  2. Design: We calculate loads, size the beams or lintels, specify bearings/padstones, and produce drawings/details.
  3. Building Notice submission: Your chosen Building Control body is notified; our calcs/drawings are provided.
  4. Construction & inspections: Your contractor follows the drawings; Building Control inspects key stages.
  5. Close-out: Building Control issues the Completion Certificate once they are satisfied.

Practical tips to stay on programme

  • Open up early (where safe). Small trial holes or lifting a few floorboards can confirm bearings, joist directions and wall thicknesses before finalising steel sizes.
  • Share site photos. Clear, well-lit photos of the area (and any previous alterations) speed up design and reduce queries.
  • Confirm services & drains. Knowing where gas, electrics and drainage run helps avoid clashes with new structure or foundations.
  • Agree inspection points. Coordinate with your inspector so key stages are viewed before they’re covered over.
  • Keep variations documented. If the builder suggests a change, ask us to confirm it in writing so Building Control can sign it off smoothly.
Need help scoping your project?

Send us your address, brief description and any drawings/photos. We’ll advise which route (Planning/PD, Full Plans, or Building Notice) suits your scheme and provide a clear, itemised fee for the calculations, drawings and submissions you’ll need. Start your enquiry.

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