South East & East England - 0208 183 4321
South West, Wales & Midlands - 01452 346 156
North England & Scotland - 0161 820 3230
We know St Helens's housing stock and what St Helens Borough Council expects
Trusted structural calculations for extensions, lofts, and renovations across St Helens.
Based in Manchester, with engineers around the country for site visits. We've worked extensively across Merseyside and know St Helens well — the Victorian → Modern Victorian terraces, 20th-century suburban housing, new-build estates, the party wall situations that come with them.
More importantly, we know how St Helens Borough Council’s building control team operates and we write our calculations to match. That saves time on site and avoids queries coming back.
Local knowledge
PorthouseDean provides structural engineering for extensions, knock-throughs, loft conversions, and two-storey extensions in St Helens, and has delivered 9,000+ projects across England and Wales since 2012.
Structural engineering is the core of it. It isn’t where we stop.
The calculations and drawings are ours. So are the things around them that usually land on you: a date you can plan around, one place where everyone sees the same documents, and the change of mind nobody priced for. More than 9,000 projects since 2012 have run through the same process, from a single wall removal to a whole new build.
Three things you always know
Every job runs through the same process, so every customer gets the same three answers.
The price, before you commit
Tell us about the project and we’ll tell you the price and the steps that follow. No hourly rate. If the job changes, there is a free change request on every job.
The turnaround, chosen by you
Pick how fast you need it, and pay less if you can wait. You get a date to work back from.
Every step, in one place
Never wonder where it’s up to — just look. Your project hub shows what is happening now, what is next and anything we need from you, with your drawings, documents and invoice alongside. Share it directly with everyone involved in your project.
One document for building control, one for your builder
Building control gets the calculations. Your builder gets the contractor pack. If either of them has a question about the structure, it comes to us, not to you. How we check and what the process looks like.
Fixed fee. No surprises after you've committed.
No extras for building control queries.
Recent Projects Near St Helens
Single storey extension
Single storey extension
Two-storey extension
Single storey extension
Other
Send us your plans
A fixed price before you commit. No obligation, no chasing.
What people say
Frequently Asked
It depends on the size and complexity of your project, so we don't publish a price range for St Helens. Tell us about your project and you get a clear, fixed-fee quote before you commit.
It can. Depending on your location, a coal mining risk assessment may be needed. Our foundation designs will take any potential ground instability into account to ensure your building is safe.
We work with all types, from the older Victorian terraces common in the town centre to the 1960s/70s housing estates and modern homes found throughout the borough.
On a full plans application, St Helens Borough Council has five weeks to decide, or longer if you both agree it in writing (regulation 14A of the Building Regulations 2010). On a building notice there is no plans decision: building control checks the work, and our calculations, as it goes. If they raise a question about the structure, your engineer answers it.
We cover the entire borough of St Helens, including Newton-le-Willows, Rainford, Eccleston, Haydock, and surrounding areas.
If you're removing a wall, converting a loft, building an extension, or doing anything that affects the structure of your house — yes. Building control will require structural calculations before they sign off the work.
A virtual site visit is included in every quote — it's a chance to put a face to the name and talk through specific design requirements with your engineer. But we don't believe a physical visit is necessary for most residential projects. Working remotely allows us to be more economical while maintaining the same quality throughout. If your project does need a physical visit, we have engineers around the country who can arrange one.
On the date you choose when you book. The price follows the date: pick a later one and it costs less, or an earlier one if you need them sooner.
Every quote includes one free amendment because we know projects change — that's normal. Beyond that, we'll quote any further changes clearly so there are no surprises.
The quote's not the product — the project is. The moments that cost you come later: when building control query something, or your builder can't follow the drawings. That's why BC queries, an amendment and a virtual site visit are included — it's where projects actually succeed or fail.
Local Area Information
Understanding St Helens's unique characteristics helps us deliver precise structural solutions.
Structural engineering services in St Helens
Professional Structural Calculations for Merseyside Properties
Your project deserves engineers who know Merseyside inside and out. We work extensively with the area’s building heritage – Victorian → Modern constructions using Victorian terraces, 20th-century suburban housing, new-build estates. Our familiarity with St Helens Borough Council processes means fewer queries and fewer complications for your project.
Structural Calculations Tailored to Merseyside Properties
Every area has its challenges. In Merseyside, we regularly work with Glacial till over Coal Measures and sandstone bedrock, which requires specific foundation design approaches. Located on the Lancashire Coalfield, the geology is dominated by the Pennine Coal Measures Group and Sherwood Sandstone, often with a history of mining and a covering of glacial till. Our structural engineers account for these local conditions in every calculation, ensuring your extension, loft conversion, or structural alteration is built on solid foundations.
Experience Across Merseyside’s Property Types
From Mix of traditional Victorian terraces and extensive 20th-century suburban homes, we’ve worked on projects throughout Merseyside. Whether your property sits near The ‘Dream’ sculpture, World of Glass Museum, Totally Wicked Stadium or benefits from proximity to M62 motorway, St Helens Central and Junction stations, proximity to M6, we understand the local context.
Our established relationship with St Helens Borough Council building control helps expedite your project. We consistently deliver calculations that meet their standards, minimising delays and resubmissions.
Structural Engineering Services Throughout Merseyside
We provide comprehensive structural calculations across Merseyside (population: 183k), covering:
• Loft conversions and dormer additions
• Rear extensions – single and double storey
• Side and wrap-around extensions
• Load-bearing wall removal calculations
• Foundation designs and underpinning assessments
Structural Calculations Quote for Your Merseyside Project
Ready to move forward? Contact PorthouseDean for structural engineering services in Merseyside. We provide clear, competitive quotes within one business day.
Ready to get started?
Send us your plans and you'll have a clear, fixed price before you commit. Or give us a call.