Frequently asked questions
Straight answers about extensions, structural calculations, planning, Building Regulations, party walls and surveys.
Getting started
Do you offer a free consultation?
Yes. Call, WhatsApp or send us an enquiry and we'll talk through your project, the approvals you're likely to need and what we'd provide.
How much will it cost?
Every quote is tailored to the size, complexity and scope of your project. Send us a few details, or your existing drawings, and we'll give you a clear quotation.
What do you need from me to prepare a quote?
The property address, a short description of what you'd like to do and any photos or drawings you already have. Architectural drawings, survey reports, builder's sketches and existing floor plans are all helpful.
Which areas do you cover?
We work throughout the UK, including London, Birmingham, Manchester, Leeds, Liverpool, Sheffield, Nottingham, Leicester, Bristol, Coventry, Reading, Milton Keynes, Oxford, Cambridge, Luton, Watford, Slough, Southampton, Portsmouth, Brighton, Edinburgh, Glasgow and surrounding areas.
Are you insured?
Yes. We hold professional indemnity insurance (£1m), public liability insurance (£6m) and employers' liability insurance (£10m). Copies of our certificates are available on request.
Structural Engineering
Do I need a structural engineer to remove a load-bearing wall?
Yes. Building Regulations require the new beam and its supports to be designed and justified by calculation. We inspect the wall, design the beam, padstones and any temporary support, and issue calculations your builder and Building Control can work from.
What is a padstone?
A padstone is a solid block, usually concrete or engineering brick, placed under each end of a beam to spread its load safely into the wall below. Its size comes from the structural calculations.
Can you work from my architect's drawings?
Yes. Send us the architectural drawings and we'll produce the structural design to match, coordinating any changes with your architect.
How long will my calculations take?
It depends on the size and complexity of the job. We'll confirm the turnaround in your quote before you book.
Architectural Services
Do I need architectural drawings for an extension?
Yes, in practice. You will need proper drawings for planning (if your project needs it) and for Building Regulations approval, and your builder needs accurate drawings to price and build from.
What's the difference between planning drawings and Building Regulations drawings?
Planning drawings show what the finished building will look like and how it affects the street and your neighbours. Building Regulations drawings go further, covering construction details, insulation, fire safety, drainage and structure, so the work can be approved and built correctly.
Can you show me what it will look like?
Yes. We can produce 3D visualisations on request, so you can see the finished design before you commit.
Do you design commercial projects?
Yes. We work on commercial alterations, office fit-outs, restaurant and warehouse alterations, and change-of-use projects.
Planning Permission & Building Control Approvals
Do I need planning permission for a rear extension?
Not always. Many single-storey rear extensions fall under permitted development, but limits apply to size, height and location, and some homes (for example in conservation areas) have fewer rights. We'll check your property and advise. A Lawful Development Certificate gives you formal proof, which helps when you sell.
Full Plans or Building Notice — which is better?
A Full Plans application is checked and approved before work starts, which gives more certainty for larger or structural work. A Building Notice lets work start sooner, with inspections as it goes, and suits simpler jobs. We'll recommend the right one for your project.
How long does planning permission take?
Councils aim to decide most householder applications within eight weeks of the application being validated. Timescales vary by council.
What is a build over agreement?
If you plan to build over or near a public sewer, the water company (such as Thames Water) usually needs to approve it first. We prepare and submit the application for you.
Party Wall Services
When do I need to serve a party wall notice?
Usually when you build on or at the boundary line, work on an existing party wall (for example inserting a beam into it), or excavate within 3 metres (in some cases 6 metres) of a neighbouring building's foundations. Notice must be served before work starts: at least two months ahead for party wall work, and one month for new boundary walls and excavations.
What if my neighbour doesn't reply?
If your neighbour doesn't respond within 14 days, a dispute is treated as having arisen and surveyors are appointed to agree an award. We'll guide you through the process.
Who pays the surveyor's fees?
Usually the owner carrying out the work (the building owner) pays the reasonable costs of the surveyors for both sides.
Surveying Services
What is a Land Registry compliant plan?
A plan drawn to HM Land Registry's requirements (correct scale, north point and clear boundary edging) so it can be used to register land, split a title or grant a lease.
What does a CCTV drainage survey show?
A camera travels through your underground drains to show blockages, cracks, displaced joints, root intrusion and other defects. It's useful before buying a property, before building an extension near drains, or when investigating a drainage problem.
Can my survey be used for the extension design?
Yes. Our measured surveys feed straight into our architectural and structural drawings, so there's no need to measure twice.
Send us your drawings
Our team will review your documents and provide a tailored quotation. You can send us:
- Architectural drawings
- Structural drawings
- Planning drawings
- Building Regs drawings
- Survey reports
- Builder's sketches
- Existing floor plans
Talk to our team
- 0203 355 7094Office landline
- +44 7393 838722Mobile & WhatsApp
- +44 7400 759852Project enquiries & WhatsApp
- info@iravyainfra.comEmail